/*
Theme Name: QuickQ BlueHarbor Nova
Theme URI: https://quickqvpn.example.com/blueharbor-nova
Author: BlueHarbor Labs
Author URI: https://quickqvpn.example.com
Description: 面向跨境 VPN、隐私 SaaS、远程协作品牌的原创蓝色官网主题。「BlueHarbor Nova · 蓝湾星标」以深海蓝、电光蓝、暮紫蓝和冰白卡片重塑界面，保留蓝色主轴，同时形成更鲜明的深蓝星湾视觉。
Version: 37.0.0
Requires at least: 6.2
Tested up to: 6.8
Requires PHP: 7.4
License: GPLv2 or later
License URI: https://www.gnu.org/licenses/gpl-2.0.html
Text Domain: qq-tidebeacon
Tags: blog, landing-page, vpn, saas, privacy, blue, light, accessibility-ready, two-columns, three-columns
*/

/* =============================================================================
 * 00 · BlueHarbor Nova design tokens
 * ---------------------------------------------------------------------------
 * 主题代号：QuickQ BlueHarbor Nova · 蓝湾星标。
 * 视觉目标：保留蓝色主轴，同时用深海蓝、电光蓝、暮紫蓝和冰白卡片制造空间层次。
 * Logo / Favicon 使用原创星湾 Q、分层波束与定位星点，不沿用旧主题母题。
 * ============================================================================= */

:root {
  /* BlueHarbor Nova surfaces */
  --qtb-bg:           #f0f7ff;
  --qtb-bg-alt:       #d7ecff;
  --qtb-surface:      #ffffff;
  --qtb-surface-soft: #f7fbff;
  --qtb-surface-deep: #071b4f;

  /* BlueHarbor Nova ink */
  --qtb-ink:        #071b4f;
  --qtb-ink-soft:   #123d83;
  --qtb-text:       #25496f;
  --qtb-text-soft:  #627f9e;
  --qtb-text-faint: #a2b8ce;

  /* BlueHarbor Nova brand: 保留蓝色主轴，改为深海蓝 + 暮紫蓝 */
  --qtb-primary:        #1677ff;
  --qtb-primary-strong: #0758c9;
  --qtb-primary-soft:   #e8f3ff;
  --qtb-primary-deep:   #071b4f;
  --qtb-secondary:      #00a8cc;
  --qtb-azure:          #d4f7ff;

  /* BlueHarbor Nova accents */
  --qtb-cyan:           #2bd9e8;
  --qtb-cyan-strong:    #0584a1;
  --qtb-cyan-soft:      #e0fbff;

  --qtb-amber:          #7cffc8;
  --qtb-amber-strong:   #079a6c;
  --qtb-amber-soft:     #e9fff7;

  /* —— signal · 语义色（v17 与冷辅 teal / 暖辅 orange 显式区隔，避免视觉撞色） —— */
  --qtb-success: #059669;        /* emerald-600 · 潮苗翠绿（与 teal 同青系但更绿、与 orange 完全冷暖对仗） */
  --qtb-warn:    #d97706;        /* amber-600 · 警示金（与 orange 色相隔 12° 但彩度更黄） */
  --qtb-danger:  #dc2626;        /* red-600 · 紧急猩红（与 orange 区分仅靠彩度，仅用于关键场景） */

  /* —— borders & shadows · 海雾蓝阴影族 —— */
  --qtb-border:        #a8dafc;
  --qtb-border-strong: #54b8ef;
  --qtb-shadow-xs: 0 1px 2px rgba(22, 119, 255, 0.07);
  --qtb-shadow-sm: 0 2px 14px rgba(22, 119, 255, 0.12);
  --qtb-shadow:    0 18px 44px rgba(22, 119, 255, 0.17);
  --qtb-shadow-lg: 0 36px 80px rgba(7, 27, 79, 0.36);
  --qtb-glow:      0 0 0 6px rgba(22, 119, 255, 0.15),
                  0 14px 32px rgba(43, 217, 232, 0.26);
  --qtb-glow-amber: 0 0 0 6px rgba(22, 119, 255, 0.12),
                   0 14px 32px rgba(124, 255, 200, 0.26);

  /* BlueHarbor Nova hero gradient */
  --qtb-hero-grad:
    radial-gradient(ellipse 78% 86% at 82% 8%, rgba(43, 217, 232, 0.46), transparent 55%),
    radial-gradient(circle at 13% 86%, rgba(22, 119, 255, 0.32), transparent 58%),
    linear-gradient(154deg, #071b4f 0%, #0a3f8f 42%, #1677ff 72%, #7cffc8 112%);
  --qtb-tide-cyan:  radial-gradient(circle, rgba(43, 217, 232, 0.48), transparent 65%);
  --qtb-tide-amber: radial-gradient(circle, rgba(124, 255, 200, 0.34), transparent 65%);

  /* —— radius scale —— */
  --qtb-radius-xs: 8px;
  --qtb-radius-sm: 12px;
  --qtb-radius:    18px;
  --qtb-radius-lg: 26px;
  --qtb-radius-xl: 36px;
  --qtb-pill:      999px;

  /* —— layout —— */
  --qtb-container: 1180px;
  --qtb-gutter:    24px;

  /* —— motion —— */
  --qtb-ease:     cubic-bezier(0.32, 0.72, 0, 1);
  --qtb-ease-out: cubic-bezier(0.2, 0.9, 0.3, 1);
  --qtb-tx-xs:    0.18s var(--qtb-ease);
  --qtb-tx-sm:    0.26s var(--qtb-ease);
  --qtb-tx-md:    0.42s var(--qtb-ease);
  --qtb-tx-lg:    0.72s var(--qtb-ease-out);

  /* —— typography —— */
  --qtb-font:
    -apple-system, BlinkMacSystemFont, "Segoe UI Variable", "Segoe UI", Inter,
    Roboto, "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB",
    Helvetica, Arial, sans-serif;
  --qtb-font-mono:
    "JetBrains Mono", "Cascadia Code", ui-monospace, "SFMono-Regular",
    "Roboto Mono", monospace;
}

/* =============================================================================
 * 01 · Reset & base
 * ============================================================================= */

*,
*::before,
*::after { box-sizing: border-box; }

html {
  scroll-behavior: smooth;
  text-size-adjust: 100%;
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  font-family: var(--qtb-font);
  font-size: 16px;
  color: var(--qtb-text);
  background: var(--qtb-bg);
  /* BlueHarbor Nova 三轴微光：右上电光蓝、左上深蓝、底部暮紫 */
  background-image:
    radial-gradient(circle at 94% -4%,  rgba(45, 212, 255, 0.18), transparent 42%),
    radial-gradient(circle at 4% 6%,    rgba(11, 107, 255, 0.14), transparent 40%),
    radial-gradient(circle at 52% 108%, rgba(255, 138, 76, 0.14), transparent 50%);
  background-attachment: fixed;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

body.qtb-no-scroll { overflow: hidden; }

a { color: inherit; text-decoration: none; }
a[role="link"] { cursor: pointer; }

img,
svg { max-width: 100%; display: block; }

button { font-family: inherit; }

::selection {
  background: var(--qtb-cyan);
  color: #fff;
}

:focus-visible {
  outline: 3px solid var(--qtb-amber);
  outline-offset: 2px;
}

/* =============================================================================
 * 02 · Layout primitives
 * ============================================================================= */

.qtb-shell {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  overflow-x: clip;
}

.qtb-container {
  width: min(92%, var(--qtb-container));
  margin-inline: auto;
}

.qtb-main { flex: 1; }

.qtb-section { padding: 96px 0; }
.qtb-section--tight { padding-top: 32px; }
.qtb-section--alt {
  position: relative;
  background:
    linear-gradient(180deg, rgba(3, 105, 161, 0.05), transparent 55%),
    linear-gradient(180deg, rgba(20, 184, 166, 0.05), transparent 85%);
}

.qtb-section-head {
  text-align: center;
  max-width: 820px;
  margin: 0 auto 50px;
}

/* eyebrow · 深青软底 + 潮翡灯辉带渐变线 */
.qtb-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 0.76rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--qtb-primary-strong);
  background: linear-gradient(90deg, var(--qtb-primary-soft), #fff 70%);
  border: 1px solid rgba(3, 105, 161, 0.20);
  border-radius: var(--qtb-pill);
  padding: 7px 16px 7px 10px;
  margin: 0 0 16px;
}

.qtb-eyebrow::before {
  content: "";
  width: 14px;
  height: 2px;
  border-radius: 2px;
  background: linear-gradient(90deg, var(--qtb-primary), var(--qtb-cyan));
  box-shadow: 0 0 0 3px rgba(20, 184, 166, 0.18);
}

.qtb-section-head h2 {
  margin: 0 0 14px;
  font-size: clamp(1.65rem, 3.2vw, 2.4rem);
  letter-spacing: -0.01em;
  color: var(--qtb-ink);
  line-height: 1.22;
}

.qtb-section-head p {
  margin: 0;
  color: var(--qtb-text-soft);
  font-size: 1.04rem;
}

/* 渐变文字 · 深青 → 潮翡灯辉 → 丹橘焰辉 */
.qtb-gradient-text {
  background: linear-gradient(95deg, var(--qtb-primary) 12%, var(--qtb-cyan) 55%, var(--qtb-amber));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  color: transparent;
}

/* —— 屏幕阅读器专用文本 —— */
.qtb-sr {
  position: absolute !important;
  clip: rect(1px, 1px, 1px, 1px);
  width: 1px;
  height: 1px;
  overflow: hidden;
  white-space: nowrap;
}

/* —— 跳过到主内容 · a11y —— */
.qtb-skip {
  position: absolute;
  top: -40px;
  left: 12px;
  background: var(--qtb-primary);
  color: #fff;
  padding: 10px 16px;
  border-radius: var(--qtb-radius-sm);
  z-index: 999;
  transition: top 0.2s var(--qtb-ease);
}

.qtb-skip:focus { top: 12px; }

/* =============================================================================
 * 03 · Header & Navigation
 * ============================================================================= */

.qtb-header {
  position: sticky;
  top: 0;
  z-index: 60;
  background: rgba(244, 245, 251, 0.80);
  backdrop-filter: blur(18px) saturate(170%);
  -webkit-backdrop-filter: blur(18px) saturate(170%);
  border-bottom: 1px solid transparent;
  transition: border-color var(--qtb-tx-xs), box-shadow var(--qtb-tx-xs),
              background var(--qtb-tx-xs);
}

.qtb-header.is-pinned {
  border-bottom-color: rgba(3, 105, 161, 0.16);
  box-shadow: var(--qtb-shadow-sm);
  background: rgba(255, 255, 255, 0.96);
}

.qtb-header__inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 24px;
  min-height: 74px;
}

.qtb-brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  font-weight: 700;
  font-size: 1.1rem;
  white-space: nowrap;
  color: var(--qtb-ink);
}

/* logo 容器 · 深海蓝 + 右上冰青 + 左下柠檬电光点 */
.qtb-brand__mark {
  width: 40px;
  height: 40px;
  flex-shrink: 0;
  border-radius: 12px;
  background: linear-gradient(150deg, #081436 0%, #0f2c75 52%, #245bff 100%);
  padding: 7px;
  display: grid;
  place-items: center;
  box-shadow: 0 8px 24px rgba(23, 54, 181, 0.42);
  position: relative;
  overflow: hidden;
}

.qtb-brand__mark::after {
  content: "";
  position: absolute;
  inset: 0;
  background:
    radial-gradient(circle at 80% 20%, rgba(34, 211, 238, 0.58), transparent 55%),
    radial-gradient(circle at 20% 78%, rgba(200, 255, 90, 0.36), transparent 55%);
  pointer-events: none;
}

.qtb-brand__mark img,
.qtb-brand__mark svg {
  width: 100%;
  height: 100%;
  position: relative;
  z-index: 1;
}

.qtb-brand__name {
  background: linear-gradient(95deg, var(--qtb-ink) 30%, var(--qtb-primary) 65%, var(--qtb-cyan));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  color: transparent;
}

.qtb-nav { display: flex; }

.qtb-nav ul,
.qtb-mobile-nav ul {
  display: flex;
  gap: 4px;
  list-style: none;
  padding: 0;
  margin: 0;
}

.qtb-nav a {
  display: inline-flex;
  align-items: center;
  color: var(--qtb-text-soft);
  font-weight: 500;
  font-size: 0.95rem;
  padding: 9px 14px;
  border-radius: var(--qtb-radius-sm);
  transition: color var(--qtb-tx-xs), background var(--qtb-tx-xs);
  position: relative;
}

.qtb-nav a:hover,
.qtb-nav a:focus-visible,
.qtb-nav a[aria-current] {
  color: var(--qtb-primary-strong);
  background: var(--qtb-primary-soft);
}

/* 当前页指示：底部 2px 潮翡灯辉 → 丹橘焰辉朝霞渐变线 */
.qtb-nav a[aria-current]::after {
  content: "";
  position: absolute;
  left: 14px; right: 14px; bottom: 4px;
  height: 2px;
  border-radius: 2px;
  background: linear-gradient(90deg, var(--qtb-cyan), var(--qtb-amber));
}

.qtb-header__actions {
  display: flex;
  align-items: center;
  gap: 10px;
}

.qtb-menu-toggle {
  display: none;
  border: 1px solid var(--qtb-border);
  background: var(--qtb-surface);
  color: var(--qtb-ink);
  border-radius: var(--qtb-radius-sm);
  font-weight: 600;
  padding: 9px 14px;
  cursor: pointer;
  transition: background var(--qtb-tx-xs), border-color var(--qtb-tx-xs);
}

.qtb-menu-toggle:hover {
  background: var(--qtb-primary-soft);
  border-color: var(--qtb-primary);
}

/* —— 移动端抽屉 —— */
.qtb-mobile-overlay {
  position: fixed;
  inset: 0;
  z-index: 110;
  background: rgba(8, 47, 73, 0.55);
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--qtb-tx-md);
  backdrop-filter: blur(4px);
}

.qtb-mobile-overlay.is-shown {
  opacity: 1;
  pointer-events: auto;
}

.qtb-mobile-panel {
  position: fixed;
  top: 0;
  right: 0;
  width: min(82vw, 380px);
  height: 100vh;
  z-index: 120;
  background: var(--qtb-surface);
  border-left: 1px solid var(--qtb-border);
  box-shadow: -28px 0 70px rgba(8, 47, 73, 0.3);
  transform: translate3d(108%, 0, 0);
  visibility: hidden;
  pointer-events: none;
  will-change: transform;
  transition: transform 0.46s var(--qtb-ease),
              visibility 0s linear 0.46s;
  padding: 22px 0;
  touch-action: pan-y;
}

.qtb-mobile-panel.is-shown {
  transform: translate3d(0, 0, 0);
  visibility: visible;
  pointer-events: auto;
  transition: transform 0.46s var(--qtb-ease),
              visibility 0s linear 0s;
}

.qtb-mobile-panel__head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 20px;
}

.qtb-mobile-close {
  width: 38px;
  height: 38px;
  border-radius: var(--qtb-radius-sm);
  border: 1px solid var(--qtb-border);
  background: var(--qtb-surface);
  color: var(--qtb-ink);
  font-size: 1.2rem;
  cursor: pointer;
}

.qtb-mobile-nav ul {
  flex-direction: column;
  gap: 8px;
}

.qtb-mobile-nav a {
  display: block;
  border: 1px solid var(--qtb-border);
  border-radius: var(--qtb-radius-sm);
  padding: 13px 15px;
  color: var(--qtb-text);
  font-weight: 500;
  transition: background var(--qtb-tx-xs), border-color var(--qtb-tx-xs);
}

.qtb-mobile-nav a:hover {
  background: var(--qtb-primary-soft);
  border-color: var(--qtb-primary);
  color: var(--qtb-primary-strong);
}

.qtb-mobile-cta {
  display: flex;
  width: 100%;
  margin-top: 18px;
}

/* =============================================================================
 * 04 · Buttons（深青主轴 + 潮翡灯辉强调按钮 + 丹橘焰辉朝霞光晕）
 * ============================================================================= */

.qtb-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  border-radius: var(--qtb-radius-sm);
  border: 1px solid transparent;
  padding: 13px 24px;
  font-weight: 600;
  font-size: 0.97rem;
  letter-spacing: 0.01em;
  transition: transform var(--qtb-tx-xs), background var(--qtb-tx-xs),
              color var(--qtb-tx-xs), border-color var(--qtb-tx-xs),
              box-shadow var(--qtb-tx-xs);
  cursor: pointer;
  text-align: center;
  white-space: nowrap;
  position: relative;
  overflow: hidden;
  isolation: isolate;
}

.qtb-btn:focus-visible {
  outline: 3px solid var(--qtb-amber);
  outline-offset: 2px;
}

/* 主按钮 · 渊海墨青 → 深渊墨蓝；hover 在右下绽放潮翡灯辉光晕 */
.qtb-btn--primary {
  background: linear-gradient(135deg, var(--qtb-primary) 0%, var(--qtb-primary-strong) 100%);
  color: #fff;
  box-shadow: 0 10px 26px rgba(3, 105, 161, 0.40);
}

.qtb-btn--primary::before {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, var(--qtb-primary-strong) 0%, var(--qtb-primary-deep) 100%);
  opacity: 0;
  transition: opacity var(--qtb-tx-xs);
  z-index: -1;
}

.qtb-btn--primary::after {
  content: "";
  position: absolute;
  width: 80%;
  height: 220%;
  right: -25%;
  bottom: -140%;
  background: radial-gradient(ellipse, rgba(20, 184, 166, 0.55), transparent 70%);
  opacity: 0;
  transition: opacity var(--qtb-tx-md), transform var(--qtb-tx-md);
  z-index: -1;
}

.qtb-btn--primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 18px 36px rgba(3, 105, 161, 0.46),
              0 8px 22px rgba(20, 184, 166, 0.32);
}

.qtb-btn--primary:hover::before { opacity: 1; }
.qtb-btn--primary:hover::after  { opacity: 1; transform: translate(-18%, -12%); }

/* 潮翡灯辉强调按钮 · 用于二级强 CTA */
.qtb-btn--cyan {
  background: linear-gradient(135deg, var(--qtb-cyan) 0%, var(--qtb-cyan-strong) 100%);
  color: #fff;
  box-shadow: 0 10px 26px rgba(20, 184, 166, 0.42);
}

.qtb-btn--cyan:hover {
  transform: translateY(-2px);
  box-shadow: 0 18px 36px rgba(20, 184, 166, 0.52);
  filter: brightness(1.04);
}

/* 幽灵按钮 · 描边 + hover 深青填充 */
.qtb-btn--ghost {
  background: var(--qtb-surface);
  color: var(--qtb-ink);
  border-color: var(--qtb-border);
}

.qtb-btn--ghost:hover {
  border-color: var(--qtb-primary);
  color: var(--qtb-primary-strong);
  background: var(--qtb-primary-soft);
  transform: translateY(-1px);
}

/* 暗底反白按钮 · hero 内使用 */
.qtb-btn--on-dark {
  background: rgba(255, 255, 255, 0.10);
  color: #fff;
  border-color: rgba(255, 255, 255, 0.32);
  backdrop-filter: blur(6px);
}

.qtb-btn--on-dark:hover {
  background: #fff;
  color: var(--qtb-primary-strong);
}

.qtb-btn--inverted {
  background: #fff;
  color: var(--qtb-primary-strong);
}

.qtb-btn--inverted:hover {
  background: var(--qtb-cyan-soft);
  color: var(--qtb-cyan-strong);
}

.qtb-btn--lg {
  padding: 15px 30px;
  font-size: 1.02rem;
  border-radius: var(--qtb-radius);
}

/* =============================================================================
 * 05 · Hero — 蓝湾星标连接面板
 * ============================================================================= */

.qtb-hero { padding: 56px 0 36px; }

.qtb-hero__panel {
  position: relative;
  border-radius: var(--qtb-radius-xl);
  padding: 72px 60px;
  background: var(--qtb-hero-grad);
  color: #fff;
  overflow: hidden;
  box-shadow: var(--qtb-shadow-lg);
  isolation: isolate;
}

/* hero 背景：钴蓝微粒 + 斜向扫描纹（港湾航线感） */
.qtb-hero__panel::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    radial-gradient(1.2px 1.2px at 14% 22%,   rgba(255,255,255,0.85), transparent),
    radial-gradient(1px 1px   at 76% 18%,     rgba(255,255,255,0.65), transparent),
    radial-gradient(1.4px 1.4px at 36% 64%,   rgba(255,255,255,0.80), transparent),
    radial-gradient(1px 1px   at 62% 78%,     rgba(255,255,255,0.55), transparent),
    radial-gradient(1.6px 1.6px at 88% 48%,   rgba(255,255,255,0.85), transparent),
    radial-gradient(1px 1px   at 22% 86%,     rgba(255,255,255,0.50), transparent),
    repeating-linear-gradient(
      115deg,
      rgba(255, 255, 255, 0.035) 0,
      rgba(255, 255, 255, 0.035) 1px,
      transparent 1px,
      transparent 44px
    );
  mask-image: linear-gradient(180deg, rgba(0, 0, 0, 0.85), rgba(0, 0, 0, 0.5));
  -webkit-mask-image: linear-gradient(180deg, rgba(0, 0, 0, 0.85), rgba(0, 0, 0, 0.5));
  pointer-events: none;
}

/* hero 右上极光青光斑 */
.qtb-hero__panel::after {
  content: "";
  position: absolute;
  width: 620px;
  height: 620px;
  right: -180px;
  top: -260px;
  border-radius: 50%;
  background: var(--qtb-tide-cyan);
  pointer-events: none;
  z-index: 0;
}

/* hero 左下柠檬电光斑（与冰青形成对角张力） */
.qtb-hero__panel > .qtb-glow-amber {
  position: absolute;
  width: 380px;
  height: 380px;
  left: -130px;
  bottom: -140px;
  border-radius: 50%;
  background: var(--qtb-tide-amber);
  pointer-events: none;
  z-index: 0;
}

/* hero 右上航标十字光痕 */
.qtb-hero__panel > .qtb-beacon {
  position: absolute;
  width: 110px;
  height: 110px;
  right: 8%;
  top: 14%;
  pointer-events: none;
  z-index: 0;
  opacity: 0.9;
}

.qtb-hero__panel > .qtb-beacon::before,
.qtb-hero__panel > .qtb-beacon::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(90deg, transparent 0%, rgba(255, 255, 255, 0.85) 50%, transparent 100%);
  filter: blur(0.4px);
}

.qtb-hero__panel > .qtb-beacon::before {
  height: 1.5px;
  top: 50%;
  transform: translateY(-50%);
  box-shadow: 0 0 10px rgba(34, 211, 238, 0.86);
  animation: qmBeaconHorz 2.6s ease-in-out infinite;
}

.qtb-hero__panel > .qtb-beacon::after {
  width: 1.5px;
  left: 50%;
  transform: translateX(-50%);
  background: linear-gradient(180deg, transparent 0%, rgba(255, 255, 255, 0.85) 50%, transparent 100%);
  box-shadow: 0 0 10px rgba(200, 255, 90, 0.80);
  animation: qmBeaconVert 2.6s ease-in-out infinite;
}

@keyframes qmBeaconHorz {
  0%, 100% { opacity: 0.6; transform: translateY(-50%) scaleX(1);   }
  50%      { opacity: 1;   transform: translateY(-50%) scaleX(1.4); }
}

@keyframes qmBeaconVert {
  0%, 100% { opacity: 0.6; transform: translateX(-50%) scaleY(1);   }
  50%      { opacity: 1;   transform: translateX(-50%) scaleY(1.4); }
}

.qtb-hero__grid {
  position: relative;
  display: grid;
  gap: 44px;
  grid-template-columns: 1.15fr 1fr;
  align-items: center;
  z-index: 1;
}

.qtb-hero__eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-weight: 700;
  font-size: 0.78rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: #a5f3fc;
  border: 1px solid rgba(255, 255, 255, 0.30);
  border-radius: var(--qtb-pill);
  padding: 7px 16px 7px 12px;
  margin: 0 0 22px;
  background: rgba(255, 255, 255, 0.06);
  backdrop-filter: blur(6px);
}

.qtb-hero__eyebrow::before {
  content: "";
  width: 14px;
  height: 2px;
  border-radius: 2px;
  background: linear-gradient(90deg, var(--qtb-cyan), var(--qtb-amber));
  box-shadow: 0 0 0 3px rgba(20, 184, 166, 0.30);
}

.qtb-hero__title {
  margin: 0 0 20px;
  font-size: clamp(2.1rem, 4.8vw, 3.3rem);
  line-height: 1.14;
  letter-spacing: -0.025em;
  font-weight: 800;
}

/* 高亮词 · 柠檬电光 → 冰青（冷亮反相） */
.qtb-hero__title em {
  font-style: normal;
  background: linear-gradient(95deg, #d9ff6a 0%, #67e8f9 32%, #a5b4fc 76%, #ffffff 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  color: transparent;
}

.qtb-hero__lead {
  margin: 0 0 32px;
  color: rgba(255, 255, 255, 0.86);
  font-size: 1.08rem;
  max-width: 560px;
  line-height: 1.7;
}

.qtb-hero__cta-row {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
}

.qtb-hero__chips {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 24px;
}

.qtb-hero__chip {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  border: 1px solid rgba(255, 255, 255, 0.22);
  background: rgba(255, 255, 255, 0.08);
  border-radius: var(--qtb-pill);
  padding: 8px 14px;
  font-size: 0.86rem;
  color: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(4px);
}

.qtb-hero__chip::before {
  content: "";
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--qtb-amber);
  box-shadow: 0 0 0 4px rgba(200, 255, 90, 0.28);
}

/* hero 右侧实时面板 · 毛玻璃 + 深海蓝→冰青→柠檬渐变描边 */
.qtb-hero__widget {
  background: rgba(255, 255, 255, 0.08);
  border: 1px solid rgba(255, 255, 255, 0.18);
  backdrop-filter: blur(10px);
  border-radius: var(--qtb-radius);
  padding: 24px;
  position: relative;
  overflow: hidden;
}

.qtb-hero__widget::before {
  content: "";
  position: absolute;
  inset: -1px;
  border-radius: inherit;
  padding: 1px;
  background: linear-gradient(135deg,
    rgba(36, 91, 255, 0.58) 0%,
    rgba(34, 211, 238, 0.62) 50%,
    rgba(200, 255, 90, 0.52) 100%);
  -webkit-mask:
    linear-gradient(#fff 0 0) content-box,
    linear-gradient(#fff 0 0);
  -webkit-mask-composite: xor;
  mask-composite: exclude;
  pointer-events: none;
}

.qtb-hero__widget h2 {
  margin: 0 0 18px;
  font-size: 1.08rem;
  color: #fff;
  display: flex;
  align-items: center;
  gap: 8px;
}

.qtb-hero__widget h2::before {
  content: "";
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--qtb-amber);
  box-shadow: 0 0 0 4px rgba(200, 255, 90, 0.30);
  animation: qmTidePulse 1.8s ease-in-out infinite;
}

@keyframes qmTidePulse {
  0%, 100% { transform: scale(1);    opacity: 1;    }
  50%      { transform: scale(1.35); opacity: 0.55; }
}

.qtb-metric-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 12px;
}

.qtb-metric {
  border-radius: var(--qtb-radius-sm);
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid rgba(255, 255, 255, 0.14);
  padding: 14px 16px;
}

.qtb-metric small {
  display: block;
  color: rgba(255, 255, 255, 0.74);
  font-size: 0.8rem;
  margin-bottom: 4px;
}

.qtb-metric strong {
  display: block;
  font-size: 1.32rem;
  color: #fff;
  font-weight: 800;
}

/* =============================================================================
 * 06 · Trust strip / 信任 KPI 条
 * ============================================================================= */

.qtb-stats-strip { padding: 40px 0 16px; }

.qtb-stats-strip__grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 18px;
}

.qtb-stat-tile {
  background: var(--qtb-surface);
  border: 1px solid var(--qtb-border);
  border-radius: var(--qtb-radius);
  padding: 22px 22px;
  text-align: center;
  box-shadow: var(--qtb-shadow-sm);
  position: relative;
  overflow: hidden;
  transition: transform var(--qtb-tx-sm), box-shadow var(--qtb-tx-sm);
}

/* 悬停下方升起一根 深青→翡青→丹橘 三段渐变线 */
.qtb-stat-tile::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 50%;
  height: 3px;
  width: 0;
  border-radius: 3px 3px 0 0;
  background: linear-gradient(90deg, var(--qtb-primary), var(--qtb-cyan), var(--qtb-amber));
  transition: width var(--qtb-tx-md), left var(--qtb-tx-md);
}

.qtb-stat-tile:hover {
  transform: translateY(-3px);
  box-shadow: var(--qtb-shadow);
}

.qtb-stat-tile:hover::after {
  width: 70%;
  left: 15%;
}

.qtb-stat-tile strong {
  display: block;
  font-size: 1.45rem;
  color: var(--qtb-ink);
  font-weight: 800;
  letter-spacing: -0.01em;
}

.qtb-stat-tile span {
  color: var(--qtb-text-soft);
  font-size: 0.88rem;
}

/* =============================================================================
 * 07 · Card grids（功能 / 场景 / 帮助 / FAQ / 博客）
 * ============================================================================= */

.qtb-card-grid {
  display: grid;
  gap: 22px;
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

.qtb-cap-card,
.qtb-download-card,
.qtb-plan-card,
.qtb-faq-item,
.qtb-blog-card,
.qtb-help-card {
  background: var(--qtb-surface);
  border: 1px solid var(--qtb-border);
  border-radius: var(--qtb-radius);
  box-shadow: var(--qtb-shadow-xs);
  transition: transform var(--qtb-tx-md), border-color var(--qtb-tx-xs),
              box-shadow var(--qtb-tx-md);
}

.qtb-cap-card {
  padding: 28px 26px;
  position: relative;
  overflow: hidden;
}

/* 卡片 hover 左侧探出 3px 深青→翡青→丹橘渐变线 */
.qtb-cap-card::before {
  content: "";
  position: absolute;
  top: 16px;
  bottom: 16px;
  left: 0;
  width: 3px;
  border-radius: 0 3px 3px 0;
  background: linear-gradient(180deg, var(--qtb-primary), var(--qtb-cyan), var(--qtb-amber));
  transform: scaleY(0.2);
  transform-origin: top;
  opacity: 0;
  transition: transform var(--qtb-tx-md), opacity var(--qtb-tx-md);
}

.qtb-cap-card:hover {
  transform: translateY(-4px);
  border-color: rgba(3, 105, 161, 0.30);
  box-shadow: var(--qtb-shadow);
}

.qtb-cap-card:hover::before {
  transform: scaleY(1);
  opacity: 1;
}

.qtb-cap-card__icon {
  display: inline-grid;
  place-items: center;
  width: 46px;
  height: 46px;
  border-radius: 12px;
  background: linear-gradient(135deg, var(--qtb-primary-soft), var(--qtb-cyan-soft));
  font-size: 1.4rem;
  margin-bottom: 18px;
  box-shadow: 0 6px 14px rgba(3, 105, 161, 0.18);
}

.qtb-cap-card h3 {
  margin: 0 0 10px;
  font-size: 1.05rem;
  color: var(--qtb-ink);
}

.qtb-cap-card p {
  margin: 0;
  color: var(--qtb-text-soft);
  font-size: 0.94rem;
  line-height: 1.65;
}

/* =============================================================================
 * 08 · Plan cards / 订阅套餐 / 计费切换
 * ============================================================================= */

.qtb-billing-switch {
  display: inline-flex;
  align-items: center;
  margin: 0 auto 38px;
  background: var(--qtb-surface);
  border: 1px solid var(--qtb-border);
  border-radius: var(--qtb-pill);
  padding: 4px;
  gap: 4px;
  box-shadow: var(--qtb-shadow-xs);
}

.qtb-billing-switch button {
  border: 0;
  background: transparent;
  border-radius: var(--qtb-pill);
  padding: 9px 18px;
  font-size: 0.92rem;
  font-weight: 600;
  color: var(--qtb-text-soft);
  cursor: pointer;
  transition: background var(--qtb-tx-xs), color var(--qtb-tx-xs);
}

.qtb-billing-switch button.is-active {
  background: linear-gradient(135deg, var(--qtb-primary), var(--qtb-cyan));
  color: #fff;
  box-shadow: 0 6px 14px rgba(3, 105, 161, 0.32);
}

.qtb-plans {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 22px;
  align-items: stretch;
}

.qtb-plan-card {
  padding: 30px 28px;
  display: flex;
  flex-direction: column;
  gap: 12px;
  position: relative;
}

.qtb-plan-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--qtb-shadow);
  border-color: rgba(3, 105, 161, 0.30);
}

.qtb-plan-card__head {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
}

.qtb-plan-card h3 {
  margin: 0;
  font-size: 1.15rem;
  color: var(--qtb-ink);
}

.qtb-plan-card__note {
  margin: 0;
  color: var(--qtb-text-soft);
  font-size: 0.92rem;
  min-height: 38px;
}

.qtb-plan-card__price {
  margin: 6px 0 14px;
  font-weight: 800;
  font-size: 2.05rem;
  color: var(--qtb-ink);
  letter-spacing: -0.02em;
}

.qtb-plan-card__price span {
  font-size: 0.96rem;
  font-weight: 500;
  color: var(--qtb-text-soft);
  margin-left: 6px;
}

.qtb-plan-card ul {
  list-style: none;
  margin: 0 0 18px;
  padding: 0;
  flex: 1;
  display: grid;
  gap: 10px;
}

.qtb-plan-card li {
  position: relative;
  padding-left: 24px;
  font-size: 0.94rem;
  color: var(--qtb-text);
}

.qtb-plan-card li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 6px;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--qtb-primary-soft), var(--qtb-amber-soft));
  border: 1.6px solid var(--qtb-primary);
}

.qtb-plan-card li::after {
  content: "";
  position: absolute;
  left: 4px;
  top: 9px;
  width: 6px;
  height: 3px;
  border-left: 1.6px solid var(--qtb-primary);
  border-bottom: 1.6px solid var(--qtb-primary);
  transform: rotate(-45deg);
}

.qtb-plan-card .qtb-btn {
  width: 100%;
}

.qtb-plan-badge {
  display: inline-flex;
  align-items: center;
  background: var(--qtb-bg-alt);
  color: var(--qtb-text-soft);
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  padding: 4px 10px;
  border-radius: var(--qtb-pill);
  text-transform: uppercase;
}

.qtb-plan-badge--accent {
  background: linear-gradient(135deg, var(--qtb-cyan), var(--qtb-primary));
  color: #fff;
  box-shadow: 0 4px 10px rgba(20, 184, 166, 0.30);
}

/* 推荐套餐 · 渐变描边 + ribbon */
.qtb-plan-card--featured {
  border-color: transparent;
  background:
    linear-gradient(var(--qtb-surface), var(--qtb-surface)) padding-box,
    linear-gradient(140deg, var(--qtb-primary), var(--qtb-cyan) 60%, var(--qtb-amber)) border-box;
  border-width: 2px;
  border-style: solid;
  box-shadow: 0 18px 38px rgba(3, 105, 161, 0.22);
}

.qtb-plan-card--featured::after {
  content: attr(data-ribbon);
  position: absolute;
  top: -14px;
  right: 22px;
  background: linear-gradient(135deg, var(--qtb-cyan), var(--qtb-primary));
  color: #fff;
  font-size: 0.74rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  padding: 6px 14px;
  border-radius: var(--qtb-pill);
  box-shadow: 0 6px 14px rgba(20, 184, 166, 0.34);
}

/* =============================================================================
 * 09 · Comparison table
 * ============================================================================= */

.qtb-compare-wrap {
  background: var(--qtb-surface);
  border: 1px solid var(--qtb-border);
  border-radius: var(--qtb-radius);
  overflow: hidden;
  box-shadow: var(--qtb-shadow-sm);
  overflow-x: auto;
}

.qtb-compare-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.95rem;
}

.qtb-compare-table thead {
  background: linear-gradient(180deg, var(--qtb-primary-soft), transparent);
}

.qtb-compare-table th,
.qtb-compare-table td {
  padding: 16px 18px;
  text-align: left;
  border-bottom: 1px solid var(--qtb-border);
  vertical-align: top;
}

.qtb-compare-table thead th {
  font-weight: 700;
  color: var(--qtb-ink);
  font-size: 0.95rem;
}

.qtb-compare-table tbody th {
  font-weight: 600;
  color: var(--qtb-ink);
  background: var(--qtb-surface-soft);
  width: 30%;
}

.qtb-compare-table tbody tr:last-child th,
.qtb-compare-table tbody tr:last-child td {
  border-bottom: 0;
}

/* =============================================================================
 * 10 · Download cards
 * ============================================================================= */

.qtb-download-grid {
  display: grid;
  gap: 18px;
  grid-template-columns: repeat(5, minmax(0, 1fr));
}

.qtb-download-card {
  padding: 22px 20px;
  text-align: center;
  display: flex;
  flex-direction: column;
  gap: 6px;
  color: var(--qtb-text);
  position: relative;
  isolation: isolate;
  overflow: hidden;
}

.qtb-download-card::before {
  content: "";
  position: absolute;
  inset: -1px;
  border-radius: inherit;
  background: linear-gradient(135deg,
    rgba(3, 105, 161, 0) 0%,
    rgba(20, 184, 166, 0) 50%,
    rgba(249, 115, 22, 0) 100%);
  z-index: -1;
  transition: background var(--qtb-tx-md);
}

.qtb-download-card:hover {
  transform: translateY(-3px);
  border-color: rgba(3, 105, 161, 0.35);
  box-shadow: var(--qtb-shadow);
}

.qtb-download-card:hover::before {
  background: linear-gradient(135deg,
    rgba(3, 105, 161, 0.07) 0%,
    rgba(20, 184, 166, 0.05) 50%,
    rgba(249, 115, 22, 0.07) 100%);
}

.qtb-download-card__platform {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--qtb-ink);
}

.qtb-download-card__hint {
  color: var(--qtb-text-soft);
  font-size: 0.86rem;
}

/* =============================================================================
 * 11 · Testimonials carousel
 * ============================================================================= */

.qtb-testimonials {
  position: relative;
  overflow: hidden;
  padding: 4px;
}

.qtb-testimonials__track {
  display: flex;
  gap: 22px;
  transition: transform var(--qtb-tx-md);
}

.qtb-testimonial-card {
  flex: 0 0 calc((100% - 44px) / 3);
  background: var(--qtb-surface);
  border: 1px solid var(--qtb-border);
  border-radius: var(--qtb-radius);
  padding: 26px 24px;
  box-shadow: var(--qtb-shadow-xs);
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.qtb-testimonial-card p {
  margin: 0;
  color: var(--qtb-text);
  line-height: 1.7;
  font-size: 0.96rem;
}

.qtb-testimonial-card strong {
  color: var(--qtb-text-soft);
  font-weight: 600;
  font-size: 0.86rem;
}

.qtb-carousel-controls {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 18px;
  margin-top: 22px;
}

.qtb-carousel-arrow {
  width: 38px;
  height: 38px;
  border-radius: 50%;
  border: 1px solid var(--qtb-border);
  background: var(--qtb-surface);
  color: var(--qtb-ink);
  font-size: 1.1rem;
  cursor: pointer;
  transition: background var(--qtb-tx-xs), border-color var(--qtb-tx-xs);
}

.qtb-carousel-arrow:hover {
  background: var(--qtb-primary-soft);
  border-color: var(--qtb-primary);
  color: var(--qtb-primary-strong);
}

.qtb-carousel-dots {
  display: flex;
  gap: 8px;
}

.qtb-carousel-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  border: 0;
  padding: 0;
  background: var(--qtb-border-strong);
  cursor: pointer;
  transition: background var(--qtb-tx-xs), transform var(--qtb-tx-xs);
}

.qtb-carousel-dot.is-active {
  background: linear-gradient(135deg, var(--qtb-primary), var(--qtb-cyan));
  transform: scale(1.25);
}

/* =============================================================================
 * 12 · Step list（5-step quickstart）
 * ============================================================================= */

.qtb-step-list {
  list-style: none;
  padding: 0;
}

.qtb-step-list li {
  display: flex;
  gap: 16px;
  align-items: flex-start;
  background: var(--qtb-surface);
  border: 1px solid var(--qtb-border);
  border-radius: var(--qtb-radius);
  padding: 18px 22px;
  box-shadow: var(--qtb-shadow-xs);
}

.qtb-step-num {
  flex-shrink: 0;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  display: grid;
  place-items: center;
  font-weight: 800;
  color: #fff;
  background: linear-gradient(135deg, var(--qtb-primary), var(--qtb-cyan));
  box-shadow: 0 6px 14px rgba(3, 105, 161, 0.34);
}

.qtb-step-list strong {
  color: var(--qtb-ink);
}

/* =============================================================================
 * 13 · FAQ accordion
 * ============================================================================= */

.qtb-faq {
  display: grid;
  gap: 14px;
  max-width: 880px;
  margin: 0 auto;
}

.qtb-faq-item {
  padding: 0;
  overflow: hidden;
  transition: border-color var(--qtb-tx-xs), box-shadow var(--qtb-tx-xs);
}

.qtb-faq-item.is-open {
  border-color: rgba(3, 105, 161, 0.32);
  box-shadow: var(--qtb-shadow-sm);
}

.qtb-faq-question {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  border: 0;
  background: transparent;
  text-align: left;
  cursor: pointer;
  padding: 20px 22px;
  font: inherit;
  font-size: 1rem;
  font-weight: 600;
  color: var(--qtb-ink);
  transition: color var(--qtb-tx-xs);
}

.qtb-faq-question::after {
  content: "+";
  font-size: 1.4rem;
  color: var(--qtb-primary);
  transition: transform var(--qtb-tx-sm);
}

.qtb-faq-item.is-open .qtb-faq-question {
  color: var(--qtb-primary-strong);
}

.qtb-faq-item.is-open .qtb-faq-question::after {
  transform: rotate(45deg);
}

.qtb-faq-answer {
  padding: 0 22px 22px;
  color: var(--qtb-text-soft);
  line-height: 1.7;
  font-size: 0.96rem;
}

.qtb-faq-answer p { margin: 0; }

/* =============================================================================
 * 14 · Blog cards
 * ============================================================================= */

.qtb-blog-grid {
  display: grid;
  gap: 22px;
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.qtb-blog-archive {
  display: grid;
  gap: 22px;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  margin-bottom: 40px;
}

.qtb-blog-card {
  padding: 0;
  overflow: hidden;
  display: flex;
  flex-direction: column;
}

.qtb-blog-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--qtb-shadow);
  border-color: rgba(3, 105, 161, 0.30);
}

.qtb-blog-card__thumb {
  display: block;
  aspect-ratio: 16 / 9;
  background: var(--qtb-bg-alt);
  overflow: hidden;
}

.qtb-blog-card__thumb img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform var(--qtb-tx-md);
}

.qtb-blog-card:hover .qtb-blog-card__thumb img {
  transform: scale(1.04);
}

.qtb-blog-card__body {
  padding: 22px 22px 24px;
  display: flex;
  flex-direction: column;
  gap: 8px;
  flex: 1;
}

.qtb-blog-card__meta {
  margin: 0;
  font-size: 0.82rem;
  color: var(--qtb-text-faint);
}

.qtb-blog-card__title {
  margin: 0;
  font-size: 1.05rem;
  line-height: 1.45;
}

.qtb-blog-card__title a {
  color: var(--qtb-ink);
  transition: color var(--qtb-tx-xs);
}

.qtb-blog-card__title a:hover {
  color: var(--qtb-primary-strong);
}

.qtb-blog-card__excerpt {
  margin: 0;
  color: var(--qtb-text-soft);
  font-size: 0.92rem;
  line-height: 1.65;
  flex: 1;
}

.qtb-blog-card__link {
  margin-top: 8px;
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--qtb-primary);
  align-self: flex-start;
  transition: color var(--qtb-tx-xs);
}

.qtb-blog-card__link:hover { color: var(--qtb-cyan-strong); }

/* =============================================================================
 * 15 · Tag cloud
 * ============================================================================= */

.qtb-tag-cloud {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.qtb-tag-cloud a {
  display: inline-flex;
  background: var(--qtb-surface);
  border: 1px solid var(--qtb-border);
  color: var(--qtb-text);
  padding: 7px 14px;
  border-radius: var(--qtb-pill);
  font-size: 0.88rem;
  transition: background var(--qtb-tx-xs), color var(--qtb-tx-xs),
              border-color var(--qtb-tx-xs);
}

.qtb-tag-cloud a:hover {
  background: linear-gradient(135deg, var(--qtb-primary-soft), var(--qtb-cyan-soft));
  border-color: var(--qtb-primary);
  color: var(--qtb-primary-strong);
}

/* =============================================================================
 * 16 · CTA strip
 * ============================================================================= */

.qtb-cta-strip {
  background: var(--qtb-hero-grad);
  border-radius: var(--qtb-radius-xl);
  padding: 56px 48px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 28px;
  color: #fff;
  position: relative;
  overflow: hidden;
  box-shadow: var(--qtb-shadow-lg);
}

.qtb-cta-strip::after {
  content: "";
  position: absolute;
  width: 480px;
  height: 480px;
  right: -120px;
  top: -160px;
  border-radius: 50%;
  background: var(--qtb-tide-cyan);
  pointer-events: none;
}

.qtb-cta-strip > * { position: relative; z-index: 1; }

.qtb-cta-strip h2 {
  margin: 0 0 8px;
  font-size: clamp(1.5rem, 2.6vw, 2rem);
  letter-spacing: -0.01em;
}

.qtb-cta-strip p {
  margin: 0;
  color: rgba(255, 255, 255, 0.84);
}

.qtb-cta-strip__actions {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
}

/* =============================================================================
 * 17 · Footer
 * ============================================================================= */

.qtb-footer {
  margin-top: 80px;
  background: linear-gradient(180deg, transparent, rgba(3, 105, 161, 0.04));
  border-top: 1px solid var(--qtb-border);
  padding: 60px 0 28px;
  color: var(--qtb-text-soft);
}

.qtb-footer__inner {
  display: grid;
  grid-template-columns: 1.5fr repeat(4, minmax(0, 1fr));
  gap: 36px;
  padding-bottom: 36px;
  border-bottom: 1px solid var(--qtb-border);
}

.qtb-footer__col--brand { min-width: 0; }

.qtb-footer__contact-list {
  list-style: none;
  padding: 0;
  margin: 16px 0 0;
  display: grid;
  gap: 6px;
  font-size: 0.88rem;
  line-height: 1.55;
}

.qtb-footer__contact-list li {
  display: grid;
  grid-template-columns: minmax(110px, 140px) 1fr;
  gap: 8px;
  align-items: baseline;
}

.qtb-footer__contact-label {
  color: var(--qtb-text-faint);
  letter-spacing: 0.02em;
  font-size: 0.78rem;
  text-transform: uppercase;
  font-weight: 600;
}

.qtb-footer__contact-list a {
  color: var(--qtb-primary-strong);
  word-break: break-word;
  border-bottom: 1px dashed transparent;
  transition: color var(--qtb-tx-xs), border-color var(--qtb-tx-xs);
}

.qtb-footer__contact-list a:hover {
  color: var(--qtb-cyan-strong);
  border-bottom-color: var(--qtb-cyan);
}

/* —— v10 信任徽章带（顶置 · ISO / SOC 2 / CSA STAR） —— */
.qtb-footer__trust {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 16px;
  padding: 0 0 26px;
  border-bottom: 1px dashed var(--qtb-border);
  margin-bottom: 26px;
}

.qtb-footer__trust-label {
  color: var(--qtb-text-faint);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  font-size: 0.74rem;
  font-weight: 700;
}

.qtb-footer__trust-list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 10px;
  list-style: none;
  margin: 0;
  padding: 0;
}

.qtb-footer__trust-item {
  display: inline-flex;
  align-items: center;
  padding: 6px 12px;
  border-radius: var(--qtb-pill);
  background: var(--qtb-cyan-soft);
  color: var(--qtb-cyan-strong);
  font-weight: 700;
  font-size: 0.78rem;
  letter-spacing: 0.02em;
  border: 1px solid rgba(20, 184, 166, 0.18);
}

/* —— 社交矩阵条 —— */
.qtb-footer__social {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  align-items: center;
  font-size: 0.92rem;
  padding: 22px 0 0;
}

.qtb-footer__social-label {
  color: var(--qtb-text-faint);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  font-size: 0.74rem;
  font-weight: 700;
}

.qtb-footer__social a {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 12px;
  border-radius: var(--qtb-pill);
  background: var(--qtb-primary-soft);
  color: var(--qtb-primary-strong);
  font-weight: 600;
  font-size: 0.84rem;
  border: 1px solid transparent;
  transition: background var(--qtb-tx-xs),
              border-color var(--qtb-tx-xs),
              transform var(--qtb-tx-xs);
}

.qtb-footer__social a:hover {
  background: #fff;
  border-color: var(--qtb-primary);
  transform: translateY(-1px);
}

.qtb-footer h4 {
  margin: 0 0 16px;
  font-size: 0.92rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--qtb-ink);
}

.qtb-footer ul {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  gap: 8px;
}

.qtb-footer ul a {
  color: var(--qtb-text-soft);
  font-size: 0.92rem;
  transition: color var(--qtb-tx-xs);
}

.qtb-footer ul a:hover { color: var(--qtb-primary-strong); }

.qtb-footer__brand-text {
  margin: 12px 0 0;
  font-size: 0.92rem;
  line-height: 1.7;
  max-width: 360px;
}

.qtb-footer__brand-text a { color: var(--qtb-primary-strong); }

.qtb-footer__bottom {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 12px;
  font-size: 0.86rem;
  color: var(--qtb-text-faint);
  padding-top: 24px;
}

.qtb-footer__friends {
  display: inline-flex;
  align-items: center;
  gap: 10px;
}

.qtb-footer__friends a {
  color: var(--qtb-primary);
  transition: color var(--qtb-tx-xs);
}

.qtb-footer__friends a:hover { color: var(--qtb-cyan-strong); }

/* =============================================================================
 * 18 · Page banner（用于 blog / help / privacy / terms / about / contact）
 * ============================================================================= */

.qtb-page-banner {
  position: relative;
  padding: 96px 0 60px;
  background:
    radial-gradient(ellipse 80% 60% at 80% 10%, rgba(20, 184, 166, 0.20), transparent 55%),
    radial-gradient(ellipse 60% 50% at 12% 90%, rgba(249, 115, 22, 0.15), transparent 55%),
    linear-gradient(180deg, rgba(3, 105, 161, 0.08), transparent 100%);
  border-bottom: 1px solid var(--qtb-border);
  text-align: center;
  overflow: hidden;
}

.qtb-page-banner h1 {
  margin: 8px auto 14px;
  font-size: clamp(1.7rem, 3.2vw, 2.4rem);
  color: var(--qtb-ink);
  max-width: 880px;
  letter-spacing: -0.01em;
  line-height: 1.25;
}

.qtb-page-banner p {
  margin: 0 auto;
  max-width: 720px;
  color: var(--qtb-text-soft);
  font-size: 1rem;
}

.qtb-page-body {
  padding: 60px 0 96px;
}

/* =============================================================================
 * 19 · Breadcrumb
 * ============================================================================= */

.qtb-breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-size: 0.86rem;
  color: var(--qtb-text-soft);
  margin-bottom: 28px;
}

.qtb-breadcrumb a {
  color: var(--qtb-text-soft);
  transition: color var(--qtb-tx-xs);
}

.qtb-breadcrumb a:hover { color: var(--qtb-primary-strong); }

.qtb-breadcrumb__sep { color: var(--qtb-text-faint); }

.qtb-breadcrumb [aria-current="page"] {
  color: var(--qtb-ink);
  font-weight: 600;
}

/* =============================================================================
 * 20 · Single post
 * ============================================================================= */

.qtb-single { padding: 48px 0 96px; }

.qtb-post-header { margin-bottom: 28px; }

.qtb-post-title {
  margin: 0 0 14px;
  font-size: clamp(1.7rem, 3.4vw, 2.6rem);
  color: var(--qtb-ink);
  letter-spacing: -0.01em;
  line-height: 1.2;
}

.qtb-post-meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-size: 0.88rem;
  color: var(--qtb-text-soft);
}

.qtb-post-meta a {
  color: var(--qtb-primary);
  transition: color var(--qtb-tx-xs);
}

.qtb-post-meta a:hover { color: var(--qtb-cyan-strong); }

.qtb-post-meta__sep { color: var(--qtb-text-faint); }

.qtb-read-time {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: var(--qtb-primary-soft);
  color: var(--qtb-primary-strong);
  padding: 4px 10px;
  border-radius: var(--qtb-pill);
  font-size: 0.78rem;
  font-weight: 600;
}

.qtb-read-time::before {
  content: "⌛";
  font-size: 0.86rem;
}

/* TL;DR 摘要框 */
.qtb-tldr {
  background: linear-gradient(135deg, var(--qtb-primary-soft), var(--qtb-cyan-soft));
  border-left: 4px solid var(--qtb-primary);
  border-radius: var(--qtb-radius-sm);
  padding: 16px 20px;
  margin: 0 0 28px;
  color: var(--qtb-ink-soft);
  line-height: 1.7;
  font-size: 0.96rem;
}

.qtb-tldr strong { color: var(--qtb-primary-strong); }

.qtb-post-thumbnail {
  margin: 0 0 28px;
  border-radius: var(--qtb-radius);
  overflow: hidden;
  box-shadow: var(--qtb-shadow-sm);
}

.qtb-post-featured-image {
  width: 100%;
  height: auto;
  display: block;
}

/* TOC 自动目录 */
.qtb-toc {
  background: var(--qtb-surface);
  border: 1px solid var(--qtb-border);
  border-left: 4px solid var(--qtb-primary);
  border-radius: var(--qtb-radius-sm);
  padding: 18px 22px;
  margin: 0 0 32px;
  font-size: 0.94rem;
}

.qtb-toc strong {
  display: block;
  margin-bottom: 10px;
  color: var(--qtb-ink);
  font-size: 0.95rem;
}

.qtb-toc ol {
  margin: 0;
  padding-left: 20px;
  display: grid;
  gap: 6px;
}

.qtb-toc a {
  color: var(--qtb-text-soft);
  transition: color var(--qtb-tx-xs);
}

.qtb-toc a:hover { color: var(--qtb-primary-strong); }

/* Prose */
.qtb-prose,
.qtb-post-content {
  color: var(--qtb-text);
  line-height: 1.8;
  font-size: 1rem;
  max-width: 760px;
  margin: 0 auto;
}

.qtb-prose h2,
.qtb-post-content h2 {
  margin: 40px 0 14px;
  color: var(--qtb-ink);
  font-size: 1.4rem;
  letter-spacing: -0.005em;
  scroll-margin-top: 90px;
}

.qtb-prose h3,
.qtb-post-content h3 {
  margin: 28px 0 10px;
  color: var(--qtb-ink);
  font-size: 1.16rem;
  scroll-margin-top: 90px;
}

.qtb-prose p,
.qtb-post-content p {
  margin: 0 0 16px;
}

.qtb-prose ul,
.qtb-prose ol,
.qtb-post-content ul,
.qtb-post-content ol {
  padding-left: 22px;
  margin: 0 0 18px;
}

.qtb-prose li,
.qtb-post-content li { margin: 6px 0; }

.qtb-prose code,
.qtb-post-content code {
  font-family: var(--qtb-font-mono);
  background: var(--qtb-bg-alt);
  border: 1px solid var(--qtb-border);
  border-radius: 6px;
  padding: 2px 6px;
  font-size: 0.9em;
  color: var(--qtb-cyan-strong);
}

.qtb-prose blockquote,
.qtb-post-content blockquote {
  margin: 22px 0;
  padding: 14px 22px;
  border-left: 4px solid var(--qtb-cyan);
  background: linear-gradient(90deg, var(--qtb-cyan-soft), transparent 80%);
  color: var(--qtb-text);
  font-style: italic;
  border-radius: 0 var(--qtb-radius-sm) var(--qtb-radius-sm) 0;
}

.qtb-prose__callout {
  background: linear-gradient(135deg, var(--qtb-primary-soft), var(--qtb-amber-soft));
  border: 1px solid rgba(3, 105, 161, 0.18);
  border-radius: var(--qtb-radius);
  padding: 18px 22px;
  margin: 0 0 30px;
  color: var(--qtb-ink-soft);
  font-size: 0.97rem;
  line-height: 1.7;
}

.qtb-bullets {
  list-style: none;
  padding: 0;
  display: grid;
  gap: 8px;
}

.qtb-bullets > li {
  position: relative;
  padding-left: 22px;
}

.qtb-bullets > li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 10px;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--qtb-primary), var(--qtb-cyan));
}

/* Author bio · E-E-A-T */
.qtb-author-bio {
  display: flex;
  gap: 18px;
  align-items: flex-start;
  background: var(--qtb-surface);
  border: 1px solid var(--qtb-border);
  border-radius: var(--qtb-radius);
  padding: 22px 24px;
  margin: 40px 0 0;
  box-shadow: var(--qtb-shadow-xs);
}

.qtb-author-bio__mark {
  width: 56px;
  height: 56px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--qtb-primary), var(--qtb-cyan));
  color: #fff;
  display: grid;
  place-items: center;
  font-weight: 800;
  font-size: 1.4rem;
  flex-shrink: 0;
  box-shadow: 0 8px 20px rgba(3, 105, 161, 0.34);
}

.qtb-author-bio__body { flex: 1; }

.qtb-author-bio__name {
  display: block;
  color: var(--qtb-ink);
  font-size: 1rem;
}

.qtb-author-bio__role {
  color: var(--qtb-primary-strong);
  font-size: 0.84rem;
  margin-left: 8px;
}

.qtb-author-bio__desc {
  margin: 8px 0 0;
  color: var(--qtb-text-soft);
  font-size: 0.94rem;
  line-height: 1.7;
}

/* Related posts */
.qtb-related {
  margin: 40px 0 0;
}

.qtb-related h2 {
  margin: 0 0 16px;
  color: var(--qtb-ink);
  font-size: 1.2rem;
}

.qtb-related__grid {
  display: grid;
  gap: 14px;
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.qtb-related__item {
  display: block;
  background: var(--qtb-surface);
  border: 1px solid var(--qtb-border);
  border-radius: var(--qtb-radius-sm);
  padding: 16px 18px;
  color: var(--qtb-ink);
  transition: border-color var(--qtb-tx-xs), box-shadow var(--qtb-tx-xs),
              transform var(--qtb-tx-xs);
  font-weight: 600;
  line-height: 1.5;
  font-size: 0.94rem;
}

.qtb-related__item small {
  display: block;
  color: var(--qtb-text-faint);
  font-size: 0.78rem;
  font-weight: 500;
  margin-bottom: 4px;
}

.qtb-related__item:hover {
  border-color: rgba(3, 105, 161, 0.32);
  box-shadow: var(--qtb-shadow-sm);
  transform: translateY(-2px);
}

/* Post navigation · prev / next */
.qtb-post-nav {
  display: grid;
  gap: 14px;
  grid-template-columns: 1fr 1fr;
  margin-top: 48px;
}

.qtb-post-nav__prev,
.qtb-post-nav__next {
  background: var(--qtb-surface);
  border: 1px solid var(--qtb-border);
  border-radius: var(--qtb-radius);
  padding: 16px 20px;
  color: var(--qtb-ink);
  transition: border-color var(--qtb-tx-xs), box-shadow var(--qtb-tx-xs);
}

.qtb-post-nav__next { text-align: right; }

.qtb-post-nav__prev:hover,
.qtb-post-nav__next:hover {
  border-color: rgba(3, 105, 161, 0.32);
  box-shadow: var(--qtb-shadow-sm);
}

.qtb-post-nav__label {
  display: block;
  font-size: 0.78rem;
  color: var(--qtb-primary);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin-bottom: 4px;
}

.qtb-post-nav__title {
  display: block;
  font-weight: 600;
  font-size: 0.95rem;
}

.qtb-post-pages {
  margin: 24px 0 0;
  font-size: 0.92rem;
  color: var(--qtb-text-soft);
}

.qtb-post-pages a {
  display: inline-block;
  background: var(--qtb-surface);
  border: 1px solid var(--qtb-border);
  padding: 4px 10px;
  border-radius: var(--qtb-radius-sm);
  margin: 0 4px;
  color: var(--qtb-text);
}

/* =============================================================================
 * 21 · Help center grid
 * ============================================================================= */

.qtb-help-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 22px;
  margin-bottom: 50px;
}

.qtb-help-card {
  padding: 24px 22px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.qtb-help-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--qtb-shadow);
  border-color: rgba(3, 105, 161, 0.30);
}

.qtb-help-card__icon {
  display: inline-grid;
  place-items: center;
  width: 42px;
  height: 42px;
  border-radius: 12px;
  background: linear-gradient(135deg, var(--qtb-primary-soft), var(--qtb-amber-soft));
  font-size: 1.2rem;
}

.qtb-help-card__links {
  list-style: none;
  padding: 0;
  margin: 6px 0 0;
  display: grid;
  gap: 6px;
}

.qtb-help-card__links a {
  color: var(--qtb-text-soft);
  font-size: 0.9rem;
  transition: color var(--qtb-tx-xs);
}

.qtb-help-card__links a:hover { color: var(--qtb-primary-strong); }

.qtb-help-section {
  background: var(--qtb-surface);
  border: 1px solid var(--qtb-border);
  border-radius: var(--qtb-radius);
  padding: 28px 32px;
  margin: 0 0 24px;
  box-shadow: var(--qtb-shadow-xs);
  scroll-margin-top: 90px;
}

.qtb-help-section h2 {
  margin: 0 0 14px;
  color: var(--qtb-ink);
  font-size: 1.3rem;
  letter-spacing: -0.005em;
}

.qtb-help-section h3 {
  margin: 24px 0 10px;
  color: var(--qtb-ink);
  font-size: 1.05rem;
  scroll-margin-top: 90px;
}

.qtb-help-section p {
  margin: 0 0 14px;
  color: var(--qtb-text);
  line-height: 1.75;
}

.qtb-help-section ul {
  margin: 0 0 16px;
  padding-left: 22px;
  color: var(--qtb-text);
}

.qtb-help-section li { margin: 6px 0; }

.qtb-help-section code {
  font-family: var(--qtb-font-mono);
  background: var(--qtb-bg-alt);
  border: 1px solid var(--qtb-border);
  border-radius: 6px;
  padding: 2px 6px;
  font-size: 0.9em;
  color: var(--qtb-cyan-strong);
}

/* —— Contact 表单 + 联系信息块 —— */
.qtb-contact-grid {
  display: grid;
  grid-template-columns: 1.1fr 1fr;
  gap: 32px;
  align-items: start;
}

.qtb-contact-card {
  background: var(--qtb-surface);
  border: 1px solid var(--qtb-border);
  border-radius: var(--qtb-radius);
  padding: 26px 28px;
  box-shadow: var(--qtb-shadow-xs);
}

.qtb-contact-card h3 {
  margin: 0 0 10px;
  color: var(--qtb-ink);
}

.qtb-contact-card p,
.qtb-contact-card a {
  color: var(--qtb-text);
}

.qtb-contact-card ul {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  gap: 8px;
}

.qtb-contact-card ul li::before {
  content: "›";
  color: var(--qtb-primary);
  margin-right: 8px;
  font-weight: 700;
}

/* =============================================================================
 * 22 · Pagination
 * ============================================================================= */

.qtb-pagination {
  display: flex;
  justify-content: center;
  margin: 36px 0;
}

.qtb-pagination ul {
  list-style: none;
  display: flex;
  gap: 8px;
  padding: 0;
  margin: 0;
  flex-wrap: wrap;
  justify-content: center;
}

.qtb-pagination a,
.qtb-pagination span {
  display: inline-grid;
  place-items: center;
  min-width: 38px;
  height: 38px;
  padding: 0 12px;
  border-radius: var(--qtb-radius-sm);
  border: 1px solid var(--qtb-border);
  background: var(--qtb-surface);
  color: var(--qtb-ink);
  font-weight: 600;
  font-size: 0.92rem;
  transition: background var(--qtb-tx-xs), color var(--qtb-tx-xs),
              border-color var(--qtb-tx-xs);
}

.qtb-pagination a:hover {
  background: var(--qtb-primary-soft);
  border-color: var(--qtb-primary);
  color: var(--qtb-primary-strong);
}

.qtb-pagination .current {
  background: linear-gradient(135deg, var(--qtb-primary), var(--qtb-cyan));
  color: #fff;
  border-color: transparent;
}

/* =============================================================================
 * 23 · Responsive
 * ============================================================================= */

@media (max-width: 1024px) {
  .qtb-card-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .qtb-plans { grid-template-columns: 1fr; }
  .qtb-download-grid { grid-template-columns: repeat(3, minmax(0, 1fr)); }
  .qtb-blog-grid,
  .qtb-blog-archive { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .qtb-help-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .qtb-related__grid { grid-template-columns: 1fr; }
  .qtb-footer__inner {
    grid-template-columns: 1.4fr 1fr 1fr;
    grid-auto-rows: minmax(0, auto);
  }
  .qtb-footer__col--brand { grid-column: 1 / -1; }
  .qtb-hero__grid { grid-template-columns: 1fr; }
  .qtb-hero__panel { padding: 56px 36px; }
  .qtb-stats-strip__grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .qtb-testimonial-card { flex: 0 0 calc((100% - 22px) / 2); }
  .qtb-contact-grid { grid-template-columns: 1fr; }
}

@media (max-width: 768px) {
  .qtb-section { padding: 64px 0; }
  .qtb-card-grid { grid-template-columns: 1fr; }
  .qtb-download-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .qtb-blog-grid,
  .qtb-blog-archive,
  .qtb-help-grid { grid-template-columns: 1fr; }
  .qtb-footer__inner { grid-template-columns: 1fr; }
  .qtb-footer__col--brand { grid-column: auto; }
  .qtb-footer__contact-list li { grid-template-columns: 1fr; gap: 2px; }
  .qtb-nav { display: none; }
  .qtb-menu-toggle { display: inline-flex; }
  .qtb-hero__panel { padding: 44px 24px; }
  .qtb-hero__title { font-size: clamp(1.7rem, 7vw, 2.2rem); }
  .qtb-cta-strip { padding: 38px 28px; flex-direction: column; align-items: flex-start; }
  .qtb-testimonial-card { flex: 0 0 100%; }
  .qtb-post-nav { grid-template-columns: 1fr; }
  .qtb-help-section { padding: 22px 20px; }
}

@media (max-width: 480px) {
  .qtb-stats-strip__grid { grid-template-columns: 1fr; }
  .qtb-billing-switch { width: 100%; }
  .qtb-billing-switch button { flex: 1; }
}

/* =============================================================================
 * 24 · Reveal-on-scroll
 * ============================================================================= */

[data-qtb-reveal] {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity 0.7s var(--qtb-ease-out), transform 0.7s var(--qtb-ease-out);
}

[data-qtb-reveal].is-shown {
  opacity: 1;
  transform: none;
}

@media (prefers-reduced-motion: reduce) {
  [data-qtb-reveal] { opacity: 1; transform: none; }
  *, *::before, *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
  }
}

/* =============================================================================
 * 25 · Print stylesheet
 * ============================================================================= */

@media print {
  .qtb-header,
  .qtb-footer,
  .qtb-mobile-overlay,
  .qtb-mobile-panel,
  .qtb-cta-strip,
  .qtb-related,
  .qtb-post-nav,
  .qtb-tag-cloud,
  .qtb-skip,
  [data-qtb-reveal] { display: none !important; opacity: 1 !important; }

  body { background: #fff !important; color: #000 !important; }
  .qtb-prose, .qtb-post-content { max-width: none !important; }
  a { color: inherit !important; text-decoration: underline !important; }
  a[href]::after { content: " (" attr(href) ")"; font-size: 0.85em; color: #555; }
}

/* =============================================================================
 * 26 · Legacy shims — 兼容旧 qb-* / qp-* 类名（保护既有插件 / 编辑器内容）
 * 仅为视觉兜底；新增内容应一律使用 qtb-* 命名空间。
 * ============================================================================= */

.qb-shell, .qp-shell           { min-height: 100vh; display: flex; flex-direction: column; overflow-x: clip; }
.qb-container, .qp-container   { width: min(92%, var(--qtb-container)); margin-inline: auto; }
.qb-main, .qp-main             { flex: 1; }
.qb-section, .qp-section       { padding: 96px 0; }
.qb-prose,  .qp-prose,
.qb-post-content,
.qp-post-content               { color: var(--qtb-text); line-height: 1.8; }
.qb-footer, .qp-footer         { margin-top: 80px; padding: 60px 0 28px; }

/* =============================================================================
 * 27 · BlueHarbor Nova 协议徽章 / 蓝湾星标装饰
 * ---------------------------------------------------------------------------
 * 用法：
 *   <span class="qtb-wing-badge">WireGuard</span>
 *   <div class="qtb-trail-deco" aria-hidden="true"></div>
 * 设计意图：在文章 / 卡片中加入"双层海图折线"装饰，呼应 Logo 的定位线路母题。
 * ============================================================================= */

.qtb-wing-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 4px 12px 4px 8px;
  border-radius: var(--qtb-pill);
  background: linear-gradient(95deg,
              var(--qtb-primary-soft) 0%,
              #ffffff 100%);
  color: var(--qtb-primary-strong);
  font-size: 0.74rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  border: 1px solid rgba(3, 105, 161, 0.22);
  line-height: 1;
}

.qtb-wing-badge::before {
  content: "";
  width: 14px;
  height: 14px;
  border-radius: 999px;
  background:
    radial-gradient(circle at 30% 30%, #fdba74 0%, transparent 60%),
    radial-gradient(circle at 70% 70%, #fdba74 0%, transparent 60%),
    var(--qtb-primary);
  box-shadow: 0 0 0 2px rgba(3, 105, 161, 0.20);
}

.qtb-trail-deco {
  position: relative;
  height: 1px;
  width: 100%;
  margin: 24px 0;
  background: linear-gradient(90deg,
              transparent 0%,
              var(--qtb-primary) 18%,
              var(--qtb-cyan) 50%,
              var(--qtb-amber) 82%,
              transparent 100%);
  opacity: 0.45;
}

.qtb-trail-deco::before,
.qtb-trail-deco::after {
  content: "";
  position: absolute;
  top: -3px;
  width: 7px;
  height: 7px;
  border-radius: 999px;
}

.qtb-trail-deco::before {
  left: 18%;
  background: var(--qtb-primary);
  box-shadow: 0 0 0 4px rgba(3, 105, 161, 0.18);
}

.qtb-trail-deco::after {
  right: 18%;
  background: var(--qtb-amber);
  box-shadow: 0 0 0 4px rgba(249, 115, 22, 0.20);
}

/* =============================================================================
 * 29 · BlueHarbor Nova final visual override
 * ---------------------------------------------------------------------------
 * 最终可见层：保留蓝色基本色调，显著改为深海蓝、电光蓝、暮紫蓝和冰白卡片。
 * ============================================================================= */

:root {
  --qtb-bg:           #eef6ff;
  --qtb-bg-alt:       #dbeafe;
  --qtb-surface:      #ffffff;
  --qtb-surface-soft: #f8fbff;
  --qtb-surface-deep: #06123d;

  --qtb-ink:        #06123d;
  --qtb-ink-soft:   #17316f;
  --qtb-text:       #27476f;
  --qtb-text-soft:  #647b9a;
  --qtb-text-faint: #9fb0c7;

  --qtb-primary:        #2563eb;
  --qtb-primary-strong: #1d4ed8;
  --qtb-primary-soft:   #e7f0ff;
  --qtb-primary-deep:   #06123d;
  --qtb-secondary:      #38bdf8;
  --qtb-azure:          #dff4ff;

  --qtb-cyan:           #38bdf8;
  --qtb-cyan-strong:    #0284c7;
  --qtb-cyan-soft:      #e0f2fe;

  --qtb-amber:          #8b5cf6;
  --qtb-amber-strong:   #6d28d9;
  --qtb-amber-soft:     #f1efff;

  --qtb-border:        #b8d4ff;
  --qtb-border-strong: #60a5fa;
  --qtb-shadow-xs: 0 1px 2px rgba(37, 99, 235, 0.08);
  --qtb-shadow-sm: 0 2px 16px rgba(37, 99, 235, 0.13);
  --qtb-shadow:    0 20px 48px rgba(37, 99, 235, 0.18);
  --qtb-shadow-lg: 0 40px 86px rgba(6, 18, 61, 0.38);
  --qtb-glow:      0 0 0 6px rgba(37, 99, 235, 0.15),
                  0 16px 34px rgba(56, 189, 248, 0.28);
  --qtb-glow-amber: 0 0 0 6px rgba(139, 92, 246, 0.14),
                   0 16px 34px rgba(37, 99, 235, 0.24);

  --qtb-hero-grad:
    radial-gradient(ellipse 70% 82% at 78% 6%, rgba(96, 165, 250, 0.45), transparent 54%),
    radial-gradient(circle at 16% 84%, rgba(139, 92, 246, 0.36), transparent 56%),
    linear-gradient(150deg, #06123d 0%, #102a75 42%, #2563eb 74%, #38bdf8 112%);
  --qtb-tide-cyan:  radial-gradient(circle, rgba(56, 189, 248, 0.48), transparent 65%);
  --qtb-tide-amber: radial-gradient(circle, rgba(139, 92, 246, 0.34), transparent 65%);
}

body {
  background-image:
    radial-gradient(circle at 92% -5%, rgba(56, 189, 248, 0.22), transparent 42%),
    radial-gradient(circle at 4% 8%, rgba(37, 99, 235, 0.16), transparent 40%),
    radial-gradient(circle at 54% 108%, rgba(139, 92, 246, 0.18), transparent 50%);
}

.qtb-brand__mark {
  border-radius: 14px;
  background: linear-gradient(150deg, #06123d 0%, #1d4ed8 48%, #38bdf8 100%);
  box-shadow: 0 10px 26px rgba(37, 99, 235, 0.36);
}

.qtb-brand__mark::after {
  background:
    radial-gradient(circle at 80% 18%, rgba(224, 242, 254, 0.62), transparent 52%),
    radial-gradient(circle at 24% 82%, rgba(139, 92, 246, 0.42), transparent 58%);
}

.qtb-brand__name {
  background: linear-gradient(95deg, var(--qtb-ink) 24%, var(--qtb-primary) 58%, var(--qtb-amber));
  -webkit-background-clip: text;
  background-clip: text;
}

.qtb-hero__panel {
  background: var(--qtb-hero-grad);
}

.qtb-nav a[aria-current]::after,
.qtb-trail-deco {
  background: linear-gradient(90deg, var(--qtb-cyan), var(--qtb-primary), var(--qtb-amber));
}

.qtb-footer {
  background:
    radial-gradient(circle at 92% 0%, rgba(56, 189, 248, 0.14), transparent 30%),
    radial-gradient(circle at 10% 100%, rgba(139, 92, 246, 0.10), transparent 34%),
    linear-gradient(180deg, transparent, rgba(37, 99, 235, 0.06));
}

/* =============================================================================
 * 28 · BlueHarbor Nova archived override
 * ============================================================================= */

:root {
  --qtb-bg:           #f0f7ff;
  --qtb-bg-alt:       #d7ecff;
  --qtb-surface:      #ffffff;
  --qtb-surface-soft: #f7fbff;
  --qtb-surface-deep: #071b4f;
  --qtb-ink:          #071b4f;
  --qtb-ink-soft:     #123d83;
  --qtb-text:         #25496f;
  --qtb-text-soft:    #627f9e;
  --qtb-primary:        #1677ff;
  --qtb-primary-strong: #0758c9;
  --qtb-primary-soft:   #e8f3ff;
  --qtb-primary-deep:   #071b4f;
  --qtb-secondary:      #00a8cc;
  --qtb-cyan:           #2bd9e8;
  --qtb-cyan-strong:    #0584a1;
  --qtb-cyan-soft:      #e0fbff;
  --qtb-amber:          #7cffc8;
  --qtb-amber-strong:   #079a6c;
  --qtb-amber-soft:     #e9fff7;
  --qtb-border:         #a8dafc;
  --qtb-border-strong:  #54b8ef;
  --qtb-shadow:         0 18px 44px rgba(22, 119, 255, 0.17);
  --qtb-shadow-lg:      0 36px 80px rgba(7, 27, 79, 0.36);
  --qtb-glow:           0 0 0 6px rgba(22, 119, 255, 0.15),
                        0 14px 32px rgba(43, 217, 232, 0.26);
  --qtb-glow-amber:     0 0 0 6px rgba(22, 119, 255, 0.12),
                        0 14px 32px rgba(124, 255, 200, 0.26);
  --qtb-hero-grad:
    radial-gradient(ellipse 78% 86% at 82% 8%, rgba(43, 217, 232, 0.46), transparent 55%),
    radial-gradient(circle at 13% 86%, rgba(22, 119, 255, 0.32), transparent 58%),
    linear-gradient(154deg, #071b4f 0%, #0a3f8f 42%, #1677ff 72%, #7cffc8 112%);
}

body {
  background-color: var(--qtb-bg);
  background-image:
    radial-gradient(circle at 96% -4%, rgba(43, 217, 232, 0.18), transparent 42%),
    radial-gradient(circle at 3% 12%, rgba(22, 119, 255, 0.14), transparent 38%),
    radial-gradient(circle at 54% 110%, rgba(124, 255, 200, 0.12), transparent 46%);
}

.qtb-brand__mark {
  background:
    linear-gradient(135deg, rgba(22, 119, 255, 0.22), rgba(43, 217, 232, 0.16)),
    #f8fbff;
  box-shadow: 0 10px 28px rgba(22, 119, 255, 0.24);
}

.qtb-hero__panel {
  background:
    linear-gradient(115deg, rgba(7, 27, 79, 0.94), rgba(10, 63, 143, 0.88)),
    var(--qtb-hero-grad);
}

.qtb-hero__title em {
  background: linear-gradient(92deg, #ffffff 0%, #b6f8ff 42%, #7cffc8 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.qtb-btn--primary,
.qtb-pagination .current {
  background: linear-gradient(135deg, #1677ff 0%, #2bd9e8 58%, #7cffc8 126%);
  box-shadow: 0 16px 34px rgba(22, 119, 255, 0.26);
}

.qtb-plan-card--featured {
  border-color: rgba(22, 119, 255, 0.42);
  box-shadow: 0 28px 70px rgba(22, 119, 255, 0.22);
}

.qtb-footer {
  background:
    radial-gradient(circle at 12% 0%, rgba(43, 217, 232, 0.18), transparent 34%),
    radial-gradient(circle at 88% 10%, rgba(124, 255, 200, 0.12), transparent 36%),
    linear-gradient(180deg, #09235d 0%, #071b4f 100%);
}

/* =============================================================================
 * 28 · BlueHarbor Nova archived visual layer
 * ============================================================================= */

:root {
  --qtb-bg:           #eef6ff;
  --qtb-bg-alt:       #dbeafe;
  --qtb-surface:      #ffffff;
  --qtb-surface-soft: #f4f8ff;
  --qtb-surface-deep: #03143d;
  --qtb-ink:          #03143d;
  --qtb-ink-soft:     #173d7a;
  --qtb-text:         #274867;
  --qtb-text-soft:    #647d98;
  --qtb-primary:        #0057ff;
  --qtb-primary-strong: #003db8;
  --qtb-primary-soft:   #e5efff;
  --qtb-primary-deep:   #03143d;
  --qtb-secondary:      #6d5dfc;
  --qtb-cyan:           #25d7ff;
  --qtb-cyan-strong:    #067ea5;
  --qtb-cyan-soft:      #dcf8ff;
  --qtb-amber:          #c8ff3d;
  --qtb-amber-strong:   #6f8f00;
  --qtb-amber-soft:     #f7ffe2;
  --qtb-border:         #b8d7ff;
  --qtb-border-strong:  #76a8ff;
  --qtb-shadow:         0 18px 44px rgba(0, 87, 255, 0.18);
  --qtb-shadow-lg:      0 36px 80px rgba(3, 20, 61, 0.36);
  --qtb-glow:           0 0 0 6px rgba(0, 87, 255, 0.15),
                        0 14px 32px rgba(37, 215, 255, 0.28);
  --qtb-glow-amber:     0 0 0 6px rgba(0, 87, 255, 0.12),
                        0 14px 32px rgba(200, 255, 61, 0.28);
  --qtb-hero-grad:
    radial-gradient(ellipse 74% 84% at 84% 10%, rgba(37, 215, 255, 0.48), transparent 55%),
    radial-gradient(circle at 15% 84%, rgba(109, 93, 252, 0.36), transparent 58%),
    linear-gradient(154deg, #03143d 0%, #082b7c 40%, #0057ff 70%, #c8ff3d 112%);
}

body {
  background-color: var(--qtb-bg);
  background-image:
    radial-gradient(circle at 96% -4%, rgba(37, 215, 255, 0.20), transparent 42%),
    radial-gradient(circle at 3% 12%, rgba(109, 93, 252, 0.16), transparent 38%),
    radial-gradient(circle at 54% 110%, rgba(200, 255, 61, 0.12), transparent 46%);
}

.qtb-brand__mark {
  background:
    linear-gradient(135deg, rgba(0, 87, 255, 0.24), rgba(37, 215, 255, 0.16)),
    #f8fbff;
  box-shadow: 0 10px 28px rgba(0, 87, 255, 0.24);
}

.qtb-hero__panel {
  background:
    linear-gradient(115deg, rgba(3, 20, 61, 0.94), rgba(8, 43, 124, 0.88)),
    var(--qtb-hero-grad);
}

.qtb-hero__title em {
  background: linear-gradient(92deg, #ffffff 0%, #9ff0ff 42%, #c8ff3d 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.qtb-btn--primary,
.qtb-pagination .current {
  background: linear-gradient(135deg, #0057ff 0%, #25d7ff 58%, #c8ff3d 126%);
  box-shadow: 0 16px 34px rgba(0, 87, 255, 0.26);
}

.qtb-plan-card--featured {
  border-color: rgba(0, 87, 255, 0.42);
  box-shadow: 0 28px 70px rgba(0, 87, 255, 0.22);
}

.qtb-footer {
  background:
    radial-gradient(circle at 12% 0%, rgba(37, 215, 255, 0.18), transparent 34%),
    radial-gradient(circle at 88% 10%, rgba(200, 255, 61, 0.12), transparent 36%),
    linear-gradient(180deg, #061b4f 0%, #03143d 100%);
}

/* =============================================================================
 * 28 · BlueHarbor Nova archived skin
 * ---------------------------------------------------------------------------
 * 历史视觉层：保留蓝色基本色调，已由文件末尾 BlueHarbor Nova 覆盖层接管
 * 信号点。历史样式仍作为兼容层存在，本节负责覆盖可见主题。
 * ============================================================================= */

:root {
  --qtb-bg:           #edf5ff;
  --qtb-bg-alt:       #dbe9ff;
  --qtb-surface:      #ffffff;
  --qtb-surface-soft: #f5fbff;
  --qtb-surface-deep: #07133f;

  --qtb-ink:        #07133f;
  --qtb-ink-soft:   #123a7a;
  --qtb-text:       #294765;
  --qtb-text-soft:  #607994;
  --qtb-text-faint: #9db3ca;

  --qtb-primary:        #1f6fff;
  --qtb-primary-strong: #123fb9;
  --qtb-primary-soft:   #e5f0ff;
  --qtb-primary-deep:   #07133f;
  --qtb-secondary:      #00b8ff;
  --qtb-azure:          #bfeeff;

  --qtb-cyan:        #21d7ff;
  --qtb-cyan-strong: #087fa8;
  --qtb-cyan-soft:   #def8ff;

  --qtb-amber:        #ff8b6a;
  --qtb-amber-strong: #c94d2d;
  --qtb-amber-soft:   #fff0eb;

  --qtb-border:        #b9daf7;
  --qtb-border-strong: #7bbcff;
  --qtb-shadow-xs: 0 1px 2px rgba(31, 111, 255, 0.07);
  --qtb-shadow-sm: 0 2px 14px rgba(31, 111, 255, 0.12);
  --qtb-shadow:    0 18px 46px rgba(18, 63, 185, 0.18);
  --qtb-shadow-lg: 0 36px 84px rgba(7, 19, 63, 0.34);
  --qtb-glow:      0 0 0 6px rgba(31, 111, 255, 0.14),
                  0 16px 34px rgba(33, 215, 255, 0.28);
  --qtb-glow-amber: 0 0 0 6px rgba(31, 111, 255, 0.12),
                   0 16px 34px rgba(255, 139, 106, 0.26);

  --qtb-hero-grad:
    radial-gradient(ellipse 68% 80% at 86% 10%, rgba(33, 215, 255, 0.46), transparent 58%),
    radial-gradient(circle at 16% 82%, rgba(255, 139, 106, 0.30), transparent 58%),
    radial-gradient(circle at 62% 20%, rgba(109, 92, 255, 0.34), transparent 48%),
    linear-gradient(148deg, #07133f 0%, #0d2775 38%, #1f6fff 70%, #a7edff 100%);
  --qtb-tide-cyan:  radial-gradient(circle, rgba(33, 215, 255, 0.52), transparent 66%);
  --qtb-tide-amber: radial-gradient(circle, rgba(255, 139, 106, 0.40), transparent 66%);
}

body {
  color: var(--qtb-text);
  background-color: var(--qtb-bg);
  background-image:
    radial-gradient(circle at 90% -6%, rgba(33, 215, 255, 0.20), transparent 42%),
    radial-gradient(circle at 8% 0%, rgba(109, 92, 255, 0.15), transparent 40%),
    radial-gradient(circle at 54% 108%, rgba(255, 139, 106, 0.15), transparent 50%),
    linear-gradient(180deg, rgba(255,255,255,0.70), rgba(237,245,255,0.18));
}

.qtb-header {
  background: rgba(255, 255, 255, 0.84);
  border-bottom-color: rgba(123, 188, 255, 0.34);
  box-shadow: 0 18px 48px rgba(7, 19, 63, 0.08);
}

.qtb-brand__mark {
  background:
    radial-gradient(circle at 72% 24%, rgba(33, 215, 255, 0.70), transparent 32%),
    radial-gradient(circle at 28% 74%, rgba(255, 139, 106, 0.58), transparent 28%),
    linear-gradient(135deg, #07133f 0%, #1f6fff 66%, #21d7ff 100%);
  box-shadow: 0 14px 34px rgba(31, 111, 255, 0.24);
}

.qtb-hero__panel,
.qtb-cta-strip {
  background: var(--qtb-hero-grad);
  border: 1px solid rgba(191, 238, 255, 0.28);
  box-shadow: 0 34px 86px rgba(7, 19, 63, 0.32);
}

.qtb-hero__panel::before {
  background-image:
    linear-gradient(rgba(191, 238, 255, 0.13) 1px, transparent 1px),
    linear-gradient(90deg, rgba(191, 238, 255, 0.13) 1px, transparent 1px);
  background-size: 36px 36px;
  mask-image: linear-gradient(120deg, transparent 0%, #000 24%, #000 72%, transparent 100%);
}

.qtb-btn--primary {
  background: linear-gradient(135deg, #1f6fff, #00b8ff 60%, #21d7ff);
  box-shadow: 0 16px 34px rgba(31, 111, 255, 0.26);
}

.qtb-btn--primary:hover {
  box-shadow: 0 20px 44px rgba(31, 111, 255, 0.34);
}

.qtb-plan-card--featured {
  border-color: rgba(31, 111, 255, 0.45);
  box-shadow: 0 22px 58px rgba(18, 63, 185, 0.20);
}

.qtb-plan-badge--accent,
.qtb-footer__trust-item::before,
.qtb-wing-badge::before {
  background:
    radial-gradient(circle at 32% 28%, #fff 0%, transparent 46%),
    linear-gradient(135deg, #ff8b6a, #21d7ff);
}

.qtb-footer {
  background:
    radial-gradient(circle at 88% 6%, rgba(33, 215, 255, 0.16), transparent 34%),
    radial-gradient(circle at 12% 80%, rgba(255, 139, 106, 0.12), transparent 36%),
    linear-gradient(180deg, rgba(255,255,255,0.84), rgba(225,239,255,0.92));
  border-top-color: rgba(123, 188, 255, 0.34);
}

/* =============================================================================
 * 28 · BlueHarbor Nova archived skin
 * ---------------------------------------------------------------------------
 * 最终视觉层：保留蓝色主调，改用深海蓝、亮青蓝、紫蓝和薄荷绿，
 * 并把旧的航线感转为网格光点与湾形面板。
 * ============================================================================= */

:root {
  --qtb-bg:           #eaf3ff;
  --qtb-bg-alt:       #d8e9ff;
  --qtb-surface:      #ffffff;
  --qtb-surface-soft: #f3f8ff;
  --qtb-surface-deep: #04154a;

  --qtb-ink:        #04154a;
  --qtb-ink-soft:   #183a7a;
  --qtb-text:       #28456f;
  --qtb-text-soft:  #64789c;
  --qtb-text-faint: #a9b8d4;

  --qtb-primary:        #0b5cff;
  --qtb-primary-strong: #073bb5;
  --qtb-primary-soft:   #e3eeff;
  --qtb-primary-deep:   #04154a;
  --qtb-secondary:      #00a7ff;
  --qtb-azure:          #c7ecff;

  --qtb-cyan:        #18d5ff;
  --qtb-cyan-strong: #0878a5;
  --qtb-cyan-soft:   #dcf8ff;

  --qtb-amber:        #35f0b4;
  --qtb-amber-strong: #079b72;
  --qtb-amber-soft:   #e5fff6;

  --qtb-border:        #b8d5ff;
  --qtb-border-strong: #74b8ff;
  --qtb-shadow-xs: 0 1px 2px rgba(4, 21, 74, 0.07);
  --qtb-shadow-sm: 0 2px 14px rgba(11, 92, 255, 0.12);
  --qtb-shadow:    0 18px 44px rgba(11, 92, 255, 0.18);
  --qtb-shadow-lg: 0 36px 80px rgba(4, 21, 74, 0.34);
  --qtb-glow:      0 0 0 6px rgba(24, 213, 255, 0.16),
                  0 14px 32px rgba(11, 92, 255, 0.22);
  --qtb-glow-amber: 0 0 0 6px rgba(53, 240, 180, 0.16),
                   0 14px 32px rgba(53, 240, 180, 0.24);

  --qtb-hero-grad:
    radial-gradient(ellipse 72% 82% at 82% 10%, rgba(24, 213, 255, 0.42), transparent 58%),
    radial-gradient(circle at 16% 88%, rgba(53, 240, 180, 0.24), transparent 58%),
    radial-gradient(circle at 66% 24%, rgba(121, 74, 255, 0.30), transparent 44%),
    linear-gradient(154deg, #04154a 0%, #06266d 38%, #0b5cff 68%, #8be8ff 100%);
  --qtb-tide-cyan:  radial-gradient(circle, rgba(24, 213, 255, 0.50), transparent 65%);
  --qtb-tide-amber: radial-gradient(circle, rgba(53, 240, 180, 0.34), transparent 65%);
}

body {
  background-color: var(--qtb-bg);
  background-image:
    radial-gradient(circle at 92% -6%, rgba(24, 213, 255, 0.18), transparent 42%),
    radial-gradient(circle at 8% 2%, rgba(121, 74, 255, 0.12), transparent 38%),
    radial-gradient(circle at 52% 108%, rgba(53, 240, 180, 0.14), transparent 50%),
    linear-gradient(180deg, #f7fbff 0%, #eaf3ff 100%);
}

.qtb-brand__mark {
  border-radius: 14px;
  background: linear-gradient(145deg, #04154a 0%, #073bb5 50%, #00a7ff 100%);
  box-shadow: 0 10px 28px rgba(4, 21, 74, 0.36);
}

.qtb-brand__mark::after {
  background:
    radial-gradient(circle at 78% 18%, rgba(24, 213, 255, 0.58), transparent 55%),
    radial-gradient(circle at 22% 82%, rgba(53, 240, 180, 0.44), transparent 55%);
}

.qtb-brand__name {
  background: linear-gradient(95deg, var(--qtb-ink) 28%, var(--qtb-primary) 62%, #00a7ff 82%, #35f0b4);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  color: transparent;
}

.qtb-hero__panel,
.qtb-cta-strip {
  background: var(--qtb-hero-grad);
}

.qtb-hero__panel::before,
.qtb-cta-strip::before {
  background-image:
    linear-gradient(rgba(255,255,255,0.08) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,0.08) 1px, transparent 1px);
  background-size: 42px 42px;
  mask-image: radial-gradient(circle at 70% 25%, #000 0%, transparent 64%);
}

.qtb-btn--primary,
.qtb-billing-switch button.is-active {
  background: linear-gradient(135deg, var(--qtb-primary) 0%, #00a7ff 62%, #35f0b4 100%);
  box-shadow: 0 16px 34px rgba(11, 92, 255, 0.28);
}

.qtb-cap-card__icon,
.qtb-step-num,
.qtb-plan-badge--accent {
  background: linear-gradient(135deg, var(--qtb-primary), var(--qtb-cyan) 58%, var(--qtb-amber));
}

.qtb-nav a[aria-current]::after,
.qtb-trail-deco {
  background: linear-gradient(90deg, var(--qtb-primary), var(--qtb-cyan), var(--qtb-amber));
}

/* =============================================================================
 * 34 · BlueHarbor Nova archived visual layer
 * ---------------------------------------------------------------------------
 * 作为最终覆盖层生效：保留蓝色主调，但用更深的靛蓝底、湖蓝主按钮、
 * 历史视觉层，最终由文件末尾 BlueHarbor Nova 覆盖层接管。
 * ============================================================================= */

:root {
  --qtb-bg:           #e8f4ff;
  --qtb-bg-alt:       #d1e7ff;
  --qtb-surface:      #ffffff;
  --qtb-surface-soft: #f1f8ff;
  --qtb-surface-deep: #04154a;

  --qtb-ink:        #04154a;
  --qtb-ink-soft:   #123b7a;
  --qtb-text:       #284869;
  --qtb-text-soft:  #66819b;
  --qtb-text-faint: #9eb4c8;

  --qtb-primary:        #0b5cff;
  --qtb-primary-strong: #073bb5;
  --qtb-primary-soft:   #e4efff;
  --qtb-primary-deep:   #04154a;
  --qtb-secondary:      #18a8ff;
  --qtb-azure:          #c4ecff;

  --qtb-cyan:        #18d5ff;
  --qtb-cyan-strong: #087b93;
  --qtb-cyan-soft:   #e1fbff;

  --qtb-amber:        #35f0b4;
  --qtb-amber-strong: #9a5b00;
  --qtb-amber-soft:   #fff5dc;

  --qtb-border:        #b7d6f7;
  --qtb-border-strong: #77b6f2;
  --qtb-shadow-xs: 0 1px 2px rgba(20, 85, 255, 0.07);
  --qtb-shadow-sm: 0 2px 16px rgba(20, 85, 255, 0.12);
  --qtb-shadow:    0 22px 54px rgba(20, 85, 255, 0.18);
  --qtb-shadow-lg: 0 40px 92px rgba(7, 22, 61, 0.38);
  --qtb-glow:      0 0 0 6px rgba(85, 215, 232, 0.18),
                  0 16px 36px rgba(20, 85, 255, 0.26);
  --qtb-glow-amber: 0 0 0 6px rgba(246, 183, 60, 0.18),
                   0 16px 36px rgba(20, 85, 255, 0.18);

  --qtb-hero-grad:
    radial-gradient(ellipse 72% 82% at 76% 12%, rgba(85, 215, 232, 0.34), transparent 56%),
    radial-gradient(circle at 12% 86%, rgba(246, 183, 60, 0.24), transparent 58%),
    linear-gradient(150deg, #04154a 0%, #06266d 42%, #0b5cff 70%, #8be8ff 100%);
  --qtb-tide-cyan:  radial-gradient(circle, rgba(85, 215, 232, 0.48), transparent 65%);
  --qtb-tide-amber: radial-gradient(circle, rgba(246, 183, 60, 0.38), transparent 65%);
}

body {
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.28), transparent 30%),
    radial-gradient(circle at 88% -4%, rgba(85, 215, 232, 0.20), transparent 42%),
    radial-gradient(circle at 4% 8%, rgba(20, 85, 255, 0.16), transparent 40%),
    radial-gradient(circle at 54% 108%, rgba(246, 183, 60, 0.14), transparent 50%),
    var(--qtb-bg);
}

.qtb-header {
  background: rgba(232, 244, 255, 0.88);
}

.qtb-header.is-pinned {
  border-bottom-color: rgba(20, 85, 255, 0.18);
  background: rgba(255, 255, 255, 0.96);
}

.qtb-brand__mark {
  border-radius: 12px;
  background: linear-gradient(145deg, #04154a 0%, #0b5cff 62%, #18d5ff 100%);
  box-shadow: 0 12px 30px rgba(20, 85, 255, 0.36);
}

.qtb-brand__mark::after {
  background:
    radial-gradient(circle at 74% 22%, rgba(85, 215, 232, 0.56), transparent 54%),
    radial-gradient(circle at 24% 78%, rgba(246, 183, 60, 0.42), transparent 56%);
}

.qtb-brand__name {
  background: linear-gradient(95deg, var(--qtb-ink) 22%, var(--qtb-primary) 58%, var(--qtb-cyan));
  -webkit-background-clip: text;
  background-clip: text;
}

.qtb-hero__panel,
.qtb-page-banner,
.qtb-cta-strip {
  background: var(--qtb-hero-grad);
}

.qtb-btn--primary,
.qtb-billing-switch button.is-active,
.qtb-plan-card--featured .qtb-plan-badge,
.qtb-download-card__icon,
.qtb-cap-card__icon {
  background: linear-gradient(135deg, var(--qtb-primary), var(--qtb-cyan));
}

.qtb-cap-card,
.qtb-plan-card,
.qtb-download-card,
.qtb-blog-card,
.qtb-help-card,
.qtb-footer__trust {
  border-color: rgba(119, 182, 242, 0.58);
}

.qtb-nav a[aria-current]::after,
.qtb-trail-deco {
  background: linear-gradient(90deg, var(--qtb-primary), var(--qtb-cyan), var(--qtb-amber));
}

/* =============================================================================
 * 33 · BlueHarbor Nova archived visual layer
 * ---------------------------------------------------------------------------
 * 最终覆盖层：保留蓝色主轴，改用夜航蓝、钴蓝、极光青与星雾紫，
 * 形成原创星环控制台视觉，并覆盖前序历史变量副本。
 * ============================================================================= */

:root {
  --qtb-bg:           #eef5ff;
  --qtb-bg-alt:       #dceaff;
  --qtb-surface:      #ffffff;
  --qtb-surface-soft: #f5f8ff;
  --qtb-surface-deep: #04154a;

  --qtb-ink:        #06112d;
  --qtb-ink-soft:   #173b8f;
  --qtb-text:       #25446f;
  --qtb-text-soft:  #617596;
  --qtb-text-faint: #9baeca;

  --qtb-primary:        #0b5cff;
  --qtb-primary-strong: #0646c8;
  --qtb-primary-soft:   #e4edff;
  --qtb-primary-deep:   #04154a;
  --qtb-secondary:      #2dd4ff;
  --qtb-azure:          #b7e7ff;

  --qtb-cyan:           #2dd4ff;
  --qtb-cyan-strong:    #087fa8;
  --qtb-cyan-soft:      #ddfbff;

  --qtb-amber:          #35f0b4;
  --qtb-amber-strong:   #c84a16;
  --qtb-amber-soft:     #fff1e8;

  --qtb-border:        #bed3ff;
  --qtb-border-strong: #7ba7ff;
  --qtb-shadow-xs: 0 1px 2px rgba(35, 88, 246, 0.07);
  --qtb-shadow-sm: 0 2px 14px rgba(35, 88, 246, 0.12);
  --qtb-shadow:    0 20px 52px rgba(35, 88, 246, 0.20);
  --qtb-shadow-lg: 0 38px 88px rgba(7, 18, 47, 0.36);
  --qtb-glow:      0 0 0 6px rgba(51, 230, 255, 0.16),
                  0 16px 36px rgba(35, 88, 246, 0.28);
  --qtb-glow-amber: 0 0 0 6px rgba(139, 124, 255, 0.16),
                   0 16px 36px rgba(51, 230, 255, 0.20);

  --qtb-hero-grad:
    radial-gradient(ellipse 70% 78% at 78% 12%, rgba(51, 230, 255, 0.40), transparent 56%),
    radial-gradient(circle at 16% 88%, rgba(139, 124, 255, 0.28), transparent 58%),
    linear-gradient(152deg, #04154a 0%, #06266d 40%, #0b5cff 68%, #8be8ff 100%);
  --qtb-tide-cyan:  radial-gradient(circle, rgba(51, 230, 255, 0.48), transparent 65%);
  --qtb-tide-amber: radial-gradient(circle, rgba(139, 124, 255, 0.38), transparent 65%);
}

body {
  background:
    radial-gradient(circle at 92% -6%, rgba(51, 230, 255, 0.18), transparent 42%),
    radial-gradient(circle at 6% 4%, rgba(35, 88, 246, 0.15), transparent 40%),
    radial-gradient(circle at 50% 108%, rgba(139, 124, 255, 0.13), transparent 52%),
    var(--qtb-bg);
}

.qtb-header {
  background: rgba(238, 245, 255, 0.86);
}

.qtb-header.is-pinned {
  border-bottom-color: rgba(35, 88, 246, 0.20);
  background: rgba(255, 255, 255, 0.96);
}

.qtb-brand__mark {
  border-radius: 14px;
  background: linear-gradient(145deg, #04154a 0%, #0b5cff 58%, #18d5ff 100%);
  box-shadow: 0 12px 30px rgba(35, 88, 246, 0.38);
}

.qtb-brand__mark::after {
  background:
    radial-gradient(circle at 76% 20%, rgba(51, 230, 255, 0.58), transparent 54%),
    radial-gradient(circle at 22% 78%, rgba(139, 124, 255, 0.44), transparent 56%);
}

.qtb-hero__panel,
.qtb-page-banner,
.qtb-cta-strip {
  background: var(--qtb-hero-grad);
}

.qtb-btn--primary,
.qtb-billing-switch button.is-active,
.qtb-plan-card--featured .qtb-plan-badge,
.qtb-download-card__icon,
.qtb-cap-card__icon {
  background: linear-gradient(135deg, var(--qtb-primary), var(--qtb-cyan));
}

.qtb-nav a[aria-current]::after,
.qtb-trail-deco {
  background: linear-gradient(90deg, var(--qtb-primary), var(--qtb-cyan), var(--qtb-amber));
}

/* =============================================================================
 * 32 · BlueHarbor Nova legacy visual layer
 * ---------------------------------------------------------------------------
 * 最终覆盖层：保留蓝色主轴，使用宝石蓝、冰川蓝、电子青与晨柠绿
 * 历史样式叠层，最终由文件末尾 BlueHarbor Nova 覆盖层接管。
 * ============================================================================= */

:root {
  --qtb-bg:           #edf7ff;
  --qtb-bg-alt:       #d7e8ff;
  --qtb-surface:      #ffffff;
  --qtb-surface-soft: #f4f9ff;
  --qtb-surface-deep: #071a46;

  --qtb-ink:        #071a46;
  --qtb-ink-soft:   #17398f;
  --qtb-text:       #24476f;
  --qtb-text-soft:  #60799a;
  --qtb-text-faint: #a7b9d2;

  --qtb-primary:        #1261ff;
  --qtb-primary-strong: #0a3dd6;
  --qtb-primary-soft:   #e6f0ff;
  --qtb-primary-deep:   #071a46;
  --qtb-secondary:      #19b7e6;
  --qtb-azure:          #c7ecff;

  --qtb-cyan:        #22d3ee;
  --qtb-cyan-strong: #0891b2;
  --qtb-cyan-soft:   #dcf8ff;

  --qtb-amber:        #c8ff5a;
  --qtb-amber-strong: #6f9f05;
  --qtb-amber-soft:   #f6ffe4;

  --qtb-border:        #b9d6ff;
  --qtb-border-strong: #82b6ff;
  --qtb-shadow-xs: 0 1px 2px rgba(18, 97, 255, 0.07);
  --qtb-shadow-sm: 0 2px 14px rgba(18, 97, 255, 0.12);
  --qtb-shadow:    0 18px 44px rgba(18, 97, 255, 0.18);
  --qtb-shadow-lg: 0 36px 80px rgba(7, 26, 70, 0.36);
  --qtb-glow:      0 0 0 6px rgba(18, 97, 255, 0.15),
                  0 14px 32px rgba(34, 211, 238, 0.28);
  --qtb-glow-amber: 0 0 0 6px rgba(18, 97, 255, 0.12),
                   0 14px 32px rgba(200, 255, 90, 0.28);

  --qtb-hero-grad:
    radial-gradient(ellipse 74% 82% at 82% 14%, rgba(34, 211, 238, 0.44), transparent 56%),
    radial-gradient(circle at 15% 87%, rgba(200, 255, 90, 0.20), transparent 58%),
    linear-gradient(154deg, #071a46 0%, #0a3dd6 42%, #1261ff 70%, #8fdcff 100%);
  --qtb-tide-cyan:  radial-gradient(circle, rgba(34, 211, 238, 0.50), transparent 65%);
  --qtb-tide-amber: radial-gradient(circle, rgba(200, 255, 90, 0.38), transparent 65%);
}

body {
  background:
    radial-gradient(circle at 94% -4%, rgba(34, 211, 238, 0.17), transparent 42%),
    radial-gradient(circle at 4% 6%, rgba(18, 97, 255, 0.14), transparent 40%),
    radial-gradient(circle at 52% 108%, rgba(200, 255, 90, 0.12), transparent 50%),
    var(--qtb-bg);
}

.qtb-header {
  background: rgba(237, 247, 255, 0.84);
}

.qtb-header.is-pinned {
  border-bottom-color: rgba(18, 97, 255, 0.18);
  background: rgba(255, 255, 255, 0.96);
}

.qtb-brand__mark {
  border-radius: 13px;
  background: linear-gradient(150deg, #071a46 0%, #1261ff 58%, #19b7e6 100%);
  box-shadow: 0 10px 26px rgba(18, 97, 255, 0.36);
}

.qtb-brand__mark::after {
  background:
    radial-gradient(circle at 78% 22%, rgba(255, 138, 91, 0.52), transparent 54%),
    radial-gradient(circle at 20% 78%, rgba(53, 214, 199, 0.40), transparent 56%);
}

.qtb-brand__name {
  background: linear-gradient(95deg, var(--qtb-ink) 26%, var(--qtb-primary) 62%, var(--qtb-cyan));
  -webkit-background-clip: text;
  background-clip: text;
}

.qtb-hero__panel,
.qtb-page-banner,
.qtb-cta-strip {
  background: var(--qtb-hero-grad);
}

.qtb-btn--primary,
.qtb-billing-switch button.is-active,
.qtb-plan-card--featured .qtb-plan-badge,
.qtb-download-card__icon,
.qtb-cap-card__icon {
  background: linear-gradient(135deg, var(--qtb-primary), var(--qtb-cyan));
}

.qtb-plan-card--featured {
  border-color: rgba(53, 214, 199, 0.62);
  box-shadow: 0 26px 70px rgba(7, 94, 234, 0.22);
}

.qtb-nav a[aria-current]::after,
.qtb-trail-deco {
  background: linear-gradient(90deg, var(--qtb-primary), var(--qtb-cyan), var(--qtb-amber));
}

.qtb-wing-badge::before {
  background:
    radial-gradient(circle at 30% 30%, var(--qtb-amber) 0%, transparent 60%),
    radial-gradient(circle at 70% 70%, var(--qtb-cyan) 0%, transparent 60%),
    var(--qtb-primary);
}

/* =============================================================================
 * 31 · BlueHarbor Nova archived visual layer
 * ---------------------------------------------------------------------------
 * 历史可见层：保留蓝色主轴；最终视觉由文件末尾 BlueHarbor Nova 覆盖层接管。
 * ============================================================================= */

:root {
  --qtb-bg:           #eef5ff;
  --qtb-bg-alt:       #e2ecff;
  --qtb-surface:      #ffffff;
  --qtb-surface-soft: #f7fbff;
  --qtb-surface-deep: #06152f;

  --qtb-ink:        #07142d;
  --qtb-ink-soft:   #123a82;
  --qtb-text:       #243f68;
  --qtb-text-soft:  #5d7192;
  --qtb-text-faint: #9aaecd;

  --qtb-primary:        #0b7cff;
  --qtb-primary-strong: #0754c7;
  --qtb-primary-soft:   #dbeafe;
  --qtb-primary-deep:   #06152f;
  --qtb-secondary:      #6d5dfc;
  --qtb-azure:          #9bd8ff;

  --qtb-cyan:           #28f4c7;
  --qtb-cyan-strong:    #0f9f90;
  --qtb-cyan-soft:      #d9fff7;

  --qtb-amber:          #c7d2fe;
  --qtb-amber-strong:   #4f46e5;
  --qtb-amber-soft:     #eef2ff;

  --qtb-border:        #c5d8fb;
  --qtb-border-strong: #78b8ff;
  --qtb-shadow-xs: 0 1px 2px rgba(11, 124, 255, 0.07);
  --qtb-shadow-sm: 0 2px 16px rgba(11, 124, 255, 0.12);
  --qtb-shadow:    0 22px 54px rgba(11, 84, 199, 0.18);
  --qtb-shadow-lg: 0 44px 96px rgba(6, 21, 47, 0.34);
  --qtb-glow:      0 0 0 6px rgba(40, 244, 199, 0.16),
                  0 18px 42px rgba(109, 93, 252, 0.28);
  --qtb-glow-amber: 0 0 0 6px rgba(199, 210, 254, 0.20),
                   0 18px 42px rgba(40, 244, 199, 0.22);

  --qtb-hero-grad:
    radial-gradient(ellipse 66% 74% at 84% 10%, rgba(40, 244, 199, 0.42), transparent 58%),
    radial-gradient(circle at 18% 18%, rgba(109, 93, 252, 0.34), transparent 44%),
    radial-gradient(circle at 50% 108%, rgba(11, 124, 255, 0.42), transparent 54%),
    linear-gradient(146deg, #06152f 0%, #0a2e75 38%, #0b7cff 70%, #9bd8ff 100%);
  --qtb-tide-cyan:  radial-gradient(circle, rgba(40, 244, 199, 0.54), transparent 66%);
  --qtb-tide-amber: radial-gradient(circle, rgba(199, 210, 254, 0.52), transparent 66%);
}

body {
  color: var(--qtb-text);
  background:
    radial-gradient(circle at 92% -2%, rgba(40, 244, 199, 0.15), transparent 38%),
    radial-gradient(circle at 8% 10%, rgba(109, 93, 252, 0.13), transparent 34%),
    linear-gradient(180deg, #fbfdff 0%, var(--qtb-bg) 46%, #e8f0ff 100%);
}

.qtb-header {
  background: rgba(247, 251, 255, 0.86);
  border-bottom-color: rgba(120, 184, 255, 0.20);
  backdrop-filter: blur(18px) saturate(1.22);
}

.qtb-header.is-pinned {
  background: rgba(255, 255, 255, 0.96);
  border-bottom-color: rgba(11, 124, 255, 0.18);
}

.qtb-brand__mark {
  border-radius: 16px 10px 16px 12px;
  background:
    radial-gradient(circle at 72% 22%, rgba(40, 244, 199, 0.72), transparent 34%),
    linear-gradient(145deg, #06152f 0%, #0754c7 52%, #6d5dfc 100%);
  box-shadow: 0 14px 28px rgba(11, 84, 199, 0.30);
}

.qtb-brand__mark::after {
  background:
    linear-gradient(135deg, transparent 0 40%, rgba(255,255,255,0.28) 40% 45%, transparent 45% 100%),
    radial-gradient(circle at 25% 78%, rgba(40, 244, 199, 0.48), transparent 42%);
}

.qtb-brand__name {
  background: linear-gradient(96deg, #07142d 8%, #0b7cff 55%, #6d5dfc 82%, #0f9f90 100%);
  -webkit-background-clip: text;
  background-clip: text;
}

.qtb-hero__panel,
.qtb-cta-strip {
  background: var(--qtb-hero-grad);
  border-color: rgba(155, 216, 255, 0.30);
  box-shadow:
    0 40px 96px rgba(6, 21, 47, 0.34),
    inset 0 1px 0 rgba(255, 255, 255, 0.18);
}

.qtb-hero__panel::before {
  background-image:
    radial-gradient(circle at 10% 20%, rgba(255, 255, 255, 0.22) 0 1px, transparent 1.5px),
    radial-gradient(circle at 74% 42%, rgba(255, 255, 255, 0.18) 0 1.5px, transparent 2px),
    linear-gradient(120deg, rgba(155, 216, 255, 0.12), transparent 42%),
    repeating-linear-gradient(118deg, rgba(255, 255, 255, 0.10) 0 1px, transparent 1px 24px);
  opacity: 0.90;
}

.qtb-hero__title em,
.qtb-gradient-text {
  background: linear-gradient(96deg, #ffffff 0%, #9bd8ff 32%, #28f4c7 62%, #c7d2fe 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.qtb-btn--primary,
.qtb-billing-switch button.is-active,
.qtb-pagination .current {
  background: linear-gradient(135deg, #0b7cff 0%, #0754c7 46%, #6d5dfc 76%, #28f4c7 100%);
  box-shadow: 0 18px 36px rgba(11, 124, 255, 0.28);
}

.qtb-btn--ghost {
  background: rgba(255, 255, 255, 0.80);
  border-color: rgba(120, 184, 255, 0.34);
}

.qtb-hero__chip,
.qtb-hero__widget {
  background: rgba(6, 21, 47, 0.25);
  border-color: rgba(219, 234, 254, 0.24);
}

.qtb-cap-card,
.qtb-download-card,
.qtb-plan-card,
.qtb-faq-item,
.qtb-blog-card {
  border-color: rgba(109, 93, 252, 0.18);
}

.qtb-cap-card::before {
  background: linear-gradient(180deg, #28f4c7, #0b7cff 54%, #6d5dfc);
}

.qtb-plan-card--featured {
  background:
    linear-gradient(#fff, #fff) padding-box,
    linear-gradient(135deg, #28f4c7, #0b7cff 50%, #6d5dfc) border-box;
}

.qtb-plan-badge--accent,
.qtb-billing-switch button.is-active {
  background: linear-gradient(135deg, #28f4c7, #0b7cff 54%, #6d5dfc);
}

.qtb-page-banner {
  background:
    radial-gradient(circle at 82% 16%, rgba(40, 244, 199, 0.20), transparent 38%),
    radial-gradient(circle at 16% 12%, rgba(109, 93, 252, 0.20), transparent 34%),
    linear-gradient(180deg, #fbfdff, #eef5ff);
}

.qtb-footer {
  background:
    radial-gradient(circle at 86% 0%, rgba(40, 244, 199, 0.11), transparent 32%),
    linear-gradient(180deg, transparent, rgba(11, 124, 255, 0.08));
}

.qtb-wing-badge::before {
  background:
    radial-gradient(circle at 35% 32%, #c7d2fe 0%, transparent 60%),
    radial-gradient(circle at 70% 68%, #28f4c7 0%, transparent 60%),
    var(--qtb-primary);
  box-shadow: 0 0 0 2px rgba(11, 124, 255, 0.20);
}

/* =============================================================================
 * 30 · BlueHarbor Nova archived visible layer
 * ---------------------------------------------------------------------------
 * 历史覆盖层：保留蓝色主轴；最终视觉由文件末尾 BlueHarbor Nova 覆盖层接管。
 * ============================================================================= */

:root {
  --qtb-bg:           #edf4ff;
  --qtb-bg-alt:       #dbe9ff;
  --qtb-surface:      #ffffff;
  --qtb-surface-soft: #f5f9ff;
  --qtb-surface-deep: #081436;
  --qtb-ink:        #071b48;
  --qtb-ink-soft:   #2147a8;
  --qtb-text:       #24436f;
  --qtb-text-soft:  #60769a;
  --qtb-text-faint: #9eafcc;
  --qtb-primary:        #245bff;
  --qtb-primary-strong: #1736b5;
  --qtb-primary-soft:   #e4ecff;
  --qtb-primary-deep:   #081436;
  --qtb-secondary:      #38bdf8;
  --qtb-azure:          #bfdbfe;
  --qtb-cyan:           #22d3ee;
  --qtb-cyan-strong:    #0891b2;
  --qtb-cyan-soft:      #dffaff;
  --qtb-amber:          #c8ff5a;
  --qtb-amber-strong:   #5b7f12;
  --qtb-amber-soft:     #f2ffd5;
  --qtb-border:        #c2d2f2;
  --qtb-border-strong: #7aa7ff;
  --qtb-shadow-xs: 0 1px 2px rgba(36, 91, 255, 0.06);
  --qtb-shadow-sm: 0 2px 14px rgba(36, 91, 255, 0.11);
  --qtb-shadow:    0 18px 44px rgba(36, 91, 255, 0.18);
  --qtb-shadow-lg: 0 36px 80px rgba(8, 20, 54, 0.34);
  --qtb-glow:      0 0 0 6px rgba(36, 91, 255, 0.16),
                  0 14px 32px rgba(34, 211, 238, 0.28);
  --qtb-glow-amber: 0 0 0 6px rgba(36, 91, 255, 0.13),
                   0 14px 32px rgba(200, 255, 90, 0.26);
  --qtb-hero-grad:
    radial-gradient(ellipse 74% 82% at 82% 14%, rgba(34, 211, 238, 0.40), transparent 56%),
    radial-gradient(circle at 15% 87%, rgba(200, 255, 90, 0.20), transparent 58%),
    linear-gradient(154deg, #081436 0%, #1736b5 42%, #245bff 70%, #8bd5ff 100%);
  --qtb-tide-cyan:  radial-gradient(circle, rgba(34, 211, 238, 0.52), transparent 65%);
  --qtb-tide-amber: radial-gradient(circle, rgba(200, 255, 90, 0.42), transparent 65%);
}

body {
  color: var(--qtb-text);
  background:
    radial-gradient(circle at 96% -4%, rgba(34, 211, 238, 0.16), transparent 42%),
    radial-gradient(circle at 4% 6%, rgba(36, 91, 255, 0.14), transparent 40%),
    radial-gradient(circle at 50% 108%, rgba(200, 255, 90, 0.13), transparent 50%),
    linear-gradient(180deg, #fbfdff 0%, var(--qtb-bg) 48%, #dfeaff 100%);
}

.qtb-brand__mark {
  background:
    radial-gradient(circle at 76% 20%, rgba(200, 255, 90, 0.46), transparent 36%),
    linear-gradient(150deg, #081436 0%, #1736b5 56%, #22d3ee 100%);
  box-shadow: 0 12px 28px rgba(36, 91, 255, 0.30);
}

.qtb-btn--primary,
.qtb-billing-switch button.is-active,
.qtb-pagination .current {
  background: linear-gradient(135deg, #245bff 0%, #1736b5 52%, #22d3ee 100%);
  box-shadow: 0 18px 34px rgba(36, 91, 255, 0.28);
}

.qtb-hero__title em,
.qtb-gradient-text {
  background: linear-gradient(96deg, #ffffff 0%, #bfdbfe 34%, #67e8f9 64%, #d9ff6a 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

/* =============================================================================
 * 28 · BlueHarbor Nova archived skin
 * ---------------------------------------------------------------------------
 * 历史兜底层，最终视觉由文件末尾 BlueHarbor Nova 覆盖层接管。
 * ============================================================================= */

:root {
  --qtb-bg:           #eef6ff;
  --qtb-bg-alt:       #dcecff;
  --qtb-surface:      #ffffff;
  --qtb-surface-soft: #f5faff;
  --qtb-surface-deep: #061a3a;
  --qtb-ink:        #071a38;
  --qtb-ink-soft:   #123b73;
  --qtb-text:       #284a6f;
  --qtb-text-soft:  #607a99;
  --qtb-text-faint: #9aadc3;
  --qtb-primary:        #1769ff;
  --qtb-primary-strong: #0b46ad;
  --qtb-primary-soft:   #dceafe;
  --qtb-primary-deep:   #061a3a;
  --qtb-secondary:      #38bdf8;
  --qtb-azure:          #b9e7ff;
  --qtb-cyan:        #2dd4bf;
  --qtb-cyan-strong: #0f766e;
  --qtb-cyan-soft:   #ddfbf5;
  --qtb-amber:       #f7b84b;
  --qtb-amber-strong:#a85f00;
  --qtb-amber-soft:  #fff3d5;
  --qtb-border:        #bed5ef;
  --qtb-border-strong: #73a7ff;
  --qtb-shadow-xs: 0 1px 2px rgba(10, 70, 173, 0.06);
  --qtb-shadow-sm: 0 2px 14px rgba(10, 70, 173, 0.12);
  --qtb-shadow:    0 18px 46px rgba(10, 70, 173, 0.18);
  --qtb-shadow-lg: 0 40px 92px rgba(6, 26, 58, 0.34);
  --qtb-glow:      0 0 0 6px rgba(23, 105, 255, 0.16),
                  0 16px 34px rgba(45, 212, 191, 0.30);
  --qtb-glow-amber: 0 0 0 6px rgba(23, 105, 255, 0.13),
                   0 16px 34px rgba(247, 184, 75, 0.26);
  --qtb-hero-grad:
    radial-gradient(circle at 82% 12%, rgba(45, 212, 191, 0.34), transparent 46%),
    radial-gradient(circle at 14% 86%, rgba(247, 184, 75, 0.20), transparent 42%),
    linear-gradient(145deg, #061a3a 0%, #0b46ad 43%, #1769ff 72%, #b9e7ff 100%);
  --qtb-tide-cyan:  radial-gradient(circle, rgba(45, 212, 191, 0.48), transparent 66%);
  --qtb-tide-amber: radial-gradient(circle, rgba(247, 184, 75, 0.38), transparent 66%);
}

body {
  background-color: var(--qtb-bg);
  background-image:
    radial-gradient(circle at 100% 0%, rgba(45, 212, 191, 0.15), transparent 38%),
    radial-gradient(circle at 0% 8%, rgba(23, 105, 255, 0.15), transparent 36%),
    linear-gradient(135deg, rgba(255,255,255,0.88) 0 12%, transparent 12% 100%);
}

.qtb-header {
  background: rgba(242, 248, 255, 0.82);
  border-bottom-color: rgba(115, 167, 255, 0.18);
}

.qtb-header.is-pinned {
  background: rgba(255, 255, 255, 0.96);
  border-bottom-color: rgba(23, 105, 255, 0.20);
}

.qtb-brand__mark {
  background:
    radial-gradient(circle at 75% 22%, rgba(247, 184, 75, 0.48), transparent 42%),
    linear-gradient(150deg, #061a3a 0%, #0b46ad 62%, #2dd4bf 100%);
  border-radius: 14px 10px 14px 10px;
  box-shadow: 0 12px 28px rgba(11, 70, 173, 0.38);
}

.qtb-brand__mark::after {
  background:
    linear-gradient(135deg, transparent 0 44%, rgba(255,255,255,0.22) 44% 48%, transparent 48%),
    radial-gradient(circle at 24% 78%, rgba(45, 212, 191, 0.40), transparent 48%);
}

.qtb-brand__name {
  background: linear-gradient(95deg, var(--qtb-ink) 18%, var(--qtb-primary) 58%, var(--qtb-cyan));
  -webkit-background-clip: text;
  background-clip: text;
}

.qtb-hero__panel,
.qtb-cta-strip {
  background: var(--qtb-hero-grad);
  border: 1px solid rgba(185, 231, 255, 0.30);
  box-shadow:
    0 38px 96px rgba(6, 26, 58, 0.35),
    inset 0 1px 0 rgba(255, 255, 255, 0.22);
}

.qtb-hero__panel::before {
  background-image:
    linear-gradient(90deg, rgba(255,255,255,0.10) 1px, transparent 1px),
    linear-gradient(0deg, rgba(255,255,255,0.08) 1px, transparent 1px),
    radial-gradient(circle at 24% 28%, rgba(255,255,255,0.22) 0 1px, transparent 1.7px),
    radial-gradient(circle at 76% 40%, rgba(247,184,75,0.28) 0 1.3px, transparent 2px);
  background-size: 72px 72px, 72px 72px, auto, auto;
  opacity: 0.56;
}

.qtb-hero__panel::after,
.qtb-cta-strip::after {
  background:
    linear-gradient(120deg, rgba(255,255,255,0.20), transparent 36%),
    radial-gradient(circle at 74% 18%, rgba(45, 212, 191, 0.38), transparent 42%);
}

.qtb-hero__title em,
.qtb-gradient-text {
  background: linear-gradient(96deg, #ffffff 0%, #b9e7ff 38%, #2dd4bf 66%, #f7b84b 100%);
  -webkit-background-clip: text;
  background-clip: text;
}

.qtb-btn--primary,
.qtb-billing-switch button.is-active,
.qtb-pagination .current {
  background: linear-gradient(135deg, #1769ff 0%, #0b46ad 54%, #2dd4bf 100%);
  box-shadow: 0 14px 28px rgba(23, 105, 255, 0.28);
}

.qtb-btn--ghost {
  background: rgba(255, 255, 255, 0.78);
  border-color: rgba(23, 105, 255, 0.22);
}

.qtb-cap-card,
.qtb-plan-card,
.qtb-blog-card,
.qtb-testimonial-card,
.qtb-faq-item {
  border-color: rgba(115, 167, 255, 0.28);
  box-shadow: 0 16px 42px rgba(10, 70, 173, 0.10);
}

.qtb-cap-card::before,
.qtb-plan-card::before {
  background: linear-gradient(90deg, var(--qtb-primary), var(--qtb-cyan), var(--qtb-amber));
}

.qtb-page-banner {
  background:
    radial-gradient(circle at 84% 18%, rgba(45, 212, 191, 0.18), transparent 38%),
    radial-gradient(circle at 12% 16%, rgba(247, 184, 75, 0.14), transparent 34%),
    linear-gradient(180deg, #f7fbff, #e7f2ff);
}

.qtb-footer {
  background:
    radial-gradient(circle at 86% 0%, rgba(45, 212, 191, 0.12), transparent 32%),
    linear-gradient(180deg, transparent, rgba(23, 105, 255, 0.08));
}

/* =============================================================================
 * 28 · BlueHarbor Nova archived skin
 * ---------------------------------------------------------------------------
 * 历史兜底层：保留蓝色主轴；最终视觉由文件末尾 BlueHarbor Nova 覆盖层接管。
 * ============================================================================= */

:root {
  --qtb-bg:           #eef6ff;
  --qtb-bg-alt:       #dcecff;
  --qtb-surface:      #ffffff;
  --qtb-surface-soft: #f5faff;
  --qtb-surface-deep: #061a3a;

  --qtb-ink:        #071a38;
  --qtb-ink-soft:   #123b73;
  --qtb-text:       #284a6f;
  --qtb-text-soft:  #607a99;
  --qtb-text-faint: #9aadc3;

  --qtb-primary:        #1769ff;
  --qtb-primary-strong: #0b46ad;
  --qtb-primary-soft:   #dceafe;
  --qtb-primary-deep:   #061a3a;
  --qtb-secondary:      #38bdf8;
  --qtb-azure:          #b9e7ff;

  --qtb-cyan:        #2dd4bf;
  --qtb-cyan-strong: #0f766e;
  --qtb-cyan-soft:   #ddfbf5;
  --qtb-amber:       #f7b84b;
  --qtb-amber-strong:#a85f00;
  --qtb-amber-soft:  #fff3d5;

  --qtb-border:        #bed5ef;
  --qtb-border-strong: #73a7ff;
  --qtb-shadow-xs: 0 1px 2px rgba(10, 70, 173, 0.06);
  --qtb-shadow-sm: 0 2px 14px rgba(10, 70, 173, 0.12);
  --qtb-shadow:    0 18px 46px rgba(10, 70, 173, 0.18);
  --qtb-shadow-lg: 0 40px 92px rgba(6, 26, 58, 0.34);
  --qtb-glow:      0 0 0 6px rgba(23, 105, 255, 0.16),
                  0 16px 34px rgba(45, 212, 191, 0.30);
  --qtb-glow-amber: 0 0 0 6px rgba(23, 105, 255, 0.13),
                   0 16px 34px rgba(247, 184, 75, 0.26);

  --qtb-hero-grad:
    radial-gradient(circle at 82% 12%, rgba(45, 212, 191, 0.34), transparent 46%),
    radial-gradient(circle at 14% 86%, rgba(247, 184, 75, 0.20), transparent 42%),
    linear-gradient(145deg, #061a3a 0%, #0b46ad 43%, #1769ff 72%, #b9e7ff 100%);
  --qtb-tide-cyan:  radial-gradient(circle, rgba(45, 212, 191, 0.48), transparent 66%);
  --qtb-tide-amber: radial-gradient(circle, rgba(247, 184, 75, 0.38), transparent 66%);
}

body {
  background-color: var(--qtb-bg);
  background-image:
    radial-gradient(circle at 100% 0%, rgba(45, 212, 191, 0.15), transparent 38%),
    radial-gradient(circle at 0% 8%, rgba(23, 105, 255, 0.15), transparent 36%),
    linear-gradient(135deg, rgba(255,255,255,0.88) 0 12%, transparent 12% 100%);
}

.qtb-header {
  background: rgba(242, 248, 255, 0.82);
  border-bottom-color: rgba(115, 167, 255, 0.18);
}

.qtb-header.is-pinned {
  background: rgba(255, 255, 255, 0.96);
  border-bottom-color: rgba(23, 105, 255, 0.20);
}

.qtb-brand__mark {
  background:
    radial-gradient(circle at 75% 22%, rgba(247, 184, 75, 0.48), transparent 42%),
    linear-gradient(150deg, #061a3a 0%, #0b46ad 62%, #2dd4bf 100%);
  border-radius: 14px 10px 14px 10px;
  box-shadow: 0 12px 28px rgba(11, 70, 173, 0.38);
}

.qtb-brand__mark::after {
  background:
    linear-gradient(135deg, transparent 0 44%, rgba(255,255,255,0.22) 44% 48%, transparent 48%),
    radial-gradient(circle at 24% 78%, rgba(45, 212, 191, 0.40), transparent 48%);
}

.qtb-brand__name {
  background: linear-gradient(95deg, var(--qtb-ink) 18%, var(--qtb-primary) 58%, var(--qtb-cyan));
  -webkit-background-clip: text;
  background-clip: text;
}

.qtb-hero__panel,
.qtb-cta-strip {
  background: var(--qtb-hero-grad);
  border: 1px solid rgba(185, 231, 255, 0.30);
  box-shadow:
    0 38px 96px rgba(6, 26, 58, 0.35),
    inset 0 1px 0 rgba(255, 255, 255, 0.22);
}

.qtb-hero__panel::before {
  background-image:
    linear-gradient(90deg, rgba(255,255,255,0.10) 1px, transparent 1px),
    linear-gradient(0deg, rgba(255,255,255,0.08) 1px, transparent 1px),
    radial-gradient(circle at 24% 28%, rgba(255,255,255,0.22) 0 1px, transparent 1.7px),
    radial-gradient(circle at 76% 40%, rgba(247,184,75,0.28) 0 1.3px, transparent 2px);
  background-size: 72px 72px, 72px 72px, auto, auto;
  opacity: 0.56;
}

.qtb-hero__panel::after,
.qtb-cta-strip::after {
  background:
    linear-gradient(120deg, rgba(255,255,255,0.20), transparent 36%),
    radial-gradient(circle at 74% 18%, rgba(45, 212, 191, 0.38), transparent 42%);
}

.qtb-hero__title em,
.qtb-gradient-text {
  background: linear-gradient(96deg, #ffffff 0%, #b9e7ff 38%, #2dd4bf 66%, #f7b84b 100%);
  -webkit-background-clip: text;
  background-clip: text;
}

.qtb-btn--primary,
.qtb-billing-switch button.is-active,
.qtb-pagination .current {
  background: linear-gradient(135deg, #1769ff 0%, #0b46ad 54%, #2dd4bf 100%);
  box-shadow: 0 14px 28px rgba(23, 105, 255, 0.28);
}

.qtb-btn--ghost {
  background: rgba(255, 255, 255, 0.78);
  border-color: rgba(23, 105, 255, 0.22);
}

.qtb-cap-card,
.qtb-plan-card,
.qtb-blog-card,
.qtb-testimonial-card,
.qtb-faq-item {
  border-color: rgba(115, 167, 255, 0.28);
  box-shadow: 0 16px 42px rgba(10, 70, 173, 0.10);
}

.qtb-cap-card::before,
.qtb-plan-card::before {
  background: linear-gradient(90deg, var(--qtb-primary), var(--qtb-cyan), var(--qtb-amber));
}

.qtb-page-banner {
  background:
    radial-gradient(circle at 84% 18%, rgba(45, 212, 191, 0.18), transparent 38%),
    radial-gradient(circle at 12% 16%, rgba(247, 184, 75, 0.14), transparent 34%),
    linear-gradient(180deg, #f7fbff, #e7f2ff);
}

.qtb-footer {
  background:
    radial-gradient(circle at 86% 0%, rgba(45, 212, 191, 0.12), transparent 32%),
    linear-gradient(180deg, transparent, rgba(23, 105, 255, 0.08));
}

/* =============================================================================
 * 28 · BlueHarbor Nova archived visual layer
 * ---------------------------------------------------------------------------
 * 文件前部保留若干历史兜底层以兼容旧内容；此处作为最终可见色板。
 * ============================================================================= */

:root {
  --qtb-bg:           #f1f7ff;
  --qtb-bg-alt:       #e0efff;
  --qtb-surface:      #ffffff;
  --qtb-surface-soft: #f7fbff;
  --qtb-surface-deep: #04245c;

  --qtb-ink:        #08204f;
  --qtb-ink-soft:   #174ea6;
  --qtb-text:       #24527f;
  --qtb-text-soft:  #5b7594;
  --qtb-text-faint: #9bb2c8;

  --qtb-primary:        #0757e8;
  --qtb-primary-strong: #063f9f;
  --qtb-primary-soft:   #dcecff;
  --qtb-primary-deep:   #04245c;
  --qtb-secondary:      #0ea5e9;
  --qtb-azure:          #a7ddff;

  --qtb-cyan:           #20d3f6;
  --qtb-cyan-strong:    #0284c7;
  --qtb-cyan-soft:      #ddf8ff;

  --qtb-amber:          #b6f24a;
  --qtb-amber-strong:   #4d7c0f;
  --qtb-amber-soft:     #f0ffd2;

  --qtb-border:        #bfd8f2;
  --qtb-border-strong: #60a5fa;
  --qtb-shadow-xs: 0 1px 2px rgba(7, 87, 232, 0.06);
  --qtb-shadow-sm: 0 2px 14px rgba(7, 87, 232, 0.11);
  --qtb-shadow:    0 18px 44px rgba(7, 87, 232, 0.18);
  --qtb-shadow-lg: 0 36px 80px rgba(4, 36, 92, 0.32);
  --qtb-glow:      0 0 0 6px rgba(7, 87, 232, 0.16),
                  0 14px 32px rgba(32, 211, 246, 0.28);
  --qtb-glow-amber: 0 0 0 6px rgba(7, 87, 232, 0.13),
                   0 14px 32px rgba(182, 242, 74, 0.26);

  --qtb-hero-grad:
    radial-gradient(ellipse 72% 78% at 84% 12%, rgba(32, 211, 246, 0.38), transparent 56%),
    radial-gradient(circle at 16% 88%, rgba(182, 242, 74, 0.18), transparent 58%),
    linear-gradient(154deg, #04245c 0%, #0757e8 44%, #0ea5e9 74%, #a7ddff 100%);
  --qtb-tide-cyan:  radial-gradient(circle, rgba(32, 211, 246, 0.50), transparent 65%);
  --qtb-tide-amber: radial-gradient(circle, rgba(182, 242, 74, 0.40), transparent 65%);
}

body {
  color: var(--qtb-text);
  background:
    radial-gradient(circle at 96% -4%, rgba(32, 211, 246, 0.14), transparent 42%),
    radial-gradient(circle at 4% 6%, rgba(7, 87, 232, 0.12), transparent 40%),
    radial-gradient(circle at 50% 108%, rgba(182, 242, 74, 0.12), transparent 50%),
    linear-gradient(180deg, #fbfdff 0%, var(--qtb-bg) 48%, #e4efff 100%);
}

.qtb-header {
  background: rgba(251, 253, 255, 0.86);
  border-bottom-color: rgba(96, 165, 250, 0.24);
  backdrop-filter: blur(18px) saturate(1.18);
}

.qtb-brand__mark {
  background:
    radial-gradient(circle at 72% 20%, rgba(182, 242, 74, 0.58), transparent 34%),
    linear-gradient(145deg, #04245c 0%, #0757e8 58%, #20d3f6 100%);
  box-shadow: 0 12px 26px rgba(7, 87, 232, 0.28);
}

.qtb-btn--primary {
  background: linear-gradient(135deg, #0757e8 0%, #0ea5e9 52%, #20d3f6 100%);
  box-shadow: 0 18px 34px rgba(7, 87, 232, 0.28);
}

.qtb-btn--primary::before {
  background: linear-gradient(135deg, #063f9f 0%, #04245c 100%);
}

.qtb-hero__title em {
  background: linear-gradient(96deg, #ffffff 0%, #a7ddff 34%, #d7ff72 72%, #ffffff 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.qtb-cap-card::before {
  background: linear-gradient(180deg, #20d3f6, #0757e8 58%, #b6f24a);
}

.qtb-plan-card--featured {
  background:
    linear-gradient(#fff, #fff) padding-box,
    linear-gradient(135deg, #20d3f6, #0757e8 52%, #b6f24a) border-box;
}

.qtb-plan-badge--accent,
.qtb-billing-switch button.is-active {
  background: linear-gradient(135deg, #20d3f6, #0757e8 56%, #0ea5e9);
}

/* =============================================================================
 * 29 · BlueHarbor Nova archived visual layer
 * ---------------------------------------------------------------------------
 * 历史色板：保留蓝色主轴，用于兼容旧缓存内容；最终色板见文件末尾。
 * ============================================================================= */

:root {
  --qtb-bg:           #eef6ff;
  --qtb-bg-alt:       #dcecff;
  --qtb-surface:      #ffffff;
  --qtb-surface-soft: #f3f9ff;
  --qtb-surface-deep: #061a3f;

  --qtb-ink:        #0b1736;
  --qtb-ink-soft:   #123b7a;
  --qtb-text:       #16356b;
  --qtb-text-soft:  #52657f;
  --qtb-text-faint: #8da2bb;

  --qtb-primary:        #155eef;
  --qtb-primary-strong: #0b3ea8;
  --qtb-primary-soft:   #d9e8ff;
  --qtb-primary-deep:   #061a3f;
  --qtb-secondary:      #2f7cff;
  --qtb-azure:          #9fd4ff;

  --qtb-cyan:           #18c9d2;
  --qtb-cyan-strong:    #07828e;
  --qtb-cyan-soft:      #d9fbff;

  --qtb-amber:          #c8ff5a;
  --qtb-amber-strong:   #c24c24;
  --qtb-amber-soft:     #ffe6d8;

  --qtb-border:        #bfd9ff;
  --qtb-border-strong: #6aa8ff;
  --qtb-shadow-xs: 0 1px 2px rgba(21, 94, 239, 0.06);
  --qtb-shadow-sm: 0 2px 14px rgba(21, 94, 239, 0.10);
  --qtb-shadow:    0 18px 44px rgba(21, 94, 239, 0.16);
  --qtb-shadow-lg: 0 36px 86px rgba(6, 26, 63, 0.34);
  --qtb-glow:      0 0 0 6px rgba(21, 94, 239, 0.15),
                  0 16px 34px rgba(24, 201, 210, 0.28);
  --qtb-glow-amber: 0 0 0 6px rgba(255, 138, 91, 0.16),
                   0 16px 34px rgba(255, 138, 91, 0.24);

  --qtb-hero-grad:
    radial-gradient(ellipse 64% 74% at 86% 12%, rgba(24, 201, 210, 0.45), transparent 58%),
    radial-gradient(circle at 16% 20%, rgba(106, 168, 255, 0.34), transparent 46%),
    radial-gradient(circle at 18% 86%, rgba(255, 138, 91, 0.28), transparent 48%),
    linear-gradient(142deg, #061a3f 0%, #0b3ea8 42%, #155eef 72%, #74c7ff 100%);
  --qtb-tide-cyan:  radial-gradient(circle, rgba(24, 201, 210, 0.54), transparent 65%);
  --qtb-tide-amber: radial-gradient(circle, rgba(255, 138, 91, 0.44), transparent 65%);
}

body {
  background-image:
    radial-gradient(circle at 96% -4%,  rgba(24, 201, 210, 0.14), transparent 42%),
    radial-gradient(circle at 2% 10%,   rgba(21, 94, 239, 0.12), transparent 40%),
    radial-gradient(circle at 50% 108%, rgba(255, 138, 91, 0.12), transparent 50%);
}

.qtb-brand__mark {
  background:
    radial-gradient(circle at 78% 18%, rgba(24, 201, 210, 0.46), transparent 36%),
    linear-gradient(145deg, #061a3f 0%, #155eef 62%, #18c9d2 100%);
  box-shadow:
    inset 0 0 0 1px rgba(255, 255, 255, 0.22),
    0 12px 28px rgba(21, 94, 239, 0.26);
}

.qtb-hero__panel::after,
.qtb-cta-strip::after {
  background:
    linear-gradient(115deg, rgba(255, 255, 255, 0.18), transparent 34%),
    radial-gradient(circle at 82% 18%, rgba(24, 201, 210, 0.28), transparent 34%),
    radial-gradient(circle at 18% 86%, rgba(255, 138, 91, 0.24), transparent 30%);
}

/* =============================================================================
 * 28 · BlueHarbor Nova legacy visual layer
 * ---------------------------------------------------------------------------
 * 保留 qtb-* 类名以兼容模板；实际可见色板切换为深钴蓝、雾蓝纸面、
 * 青绿信号光和少量暖沙色，形成与旧夜空紫蓝体系明显不同的蓝色主题。
 * ============================================================================= */

:root {
  --qtb-bg:           #edf7fb;
  --qtb-bg-alt:       #d7edf6;
  --qtb-surface:      #ffffff;
  --qtb-surface-soft: #f4fbff;
  --qtb-surface-deep: #061a3f;

  --qtb-ink:        #06192f;
  --qtb-ink-soft:   #0a315f;
  --qtb-text:       #173a5f;
  --qtb-text-soft:  #567083;
  --qtb-text-faint: #8aa2b2;

  --qtb-primary:        #155eef;
  --qtb-primary-strong: #084fb6;
  --qtb-primary-soft:   #d8ebff;
  --qtb-primary-deep:   #061a3f;
  --qtb-secondary:      #0a8fc7;
  --qtb-azure:          #8bd8ff;

  --qtb-cyan:           #00c2b8;
  --qtb-cyan-strong:    #007f78;
  --qtb-cyan-soft:      #d7fffb;

  --qtb-amber:          #f4b05e;
  --qtb-amber-strong:   #a45a13;
  --qtb-amber-soft:     #fff1dc;

  --qtb-border:        #b8d7e8;
  --qtb-border-strong: #55b7e6;
  --qtb-shadow-xs: 0 1px 2px rgba(6, 32, 63, 0.07);
  --qtb-shadow-sm: 0 2px 16px rgba(15, 111, 255, 0.10);
  --qtb-shadow:    0 24px 58px rgba(6, 32, 63, 0.16);
  --qtb-shadow-lg: 0 44px 96px rgba(6, 32, 63, 0.30);
  --qtb-glow:      0 0 0 7px rgba(0, 194, 184, 0.15),
                  0 18px 40px rgba(15, 111, 255, 0.22);
  --qtb-glow-amber: 0 0 0 7px rgba(244, 176, 94, 0.18),
                   0 18px 40px rgba(0, 194, 184, 0.18);

  --qtb-hero-grad:
    radial-gradient(ellipse 62% 70% at 86% 14%, rgba(0, 194, 184, 0.46), transparent 57%),
    radial-gradient(circle at 12% 80%, rgba(244, 176, 94, 0.28), transparent 46%),
    radial-gradient(circle at 52% 110%, rgba(139, 216, 255, 0.36), transparent 54%),
    linear-gradient(148deg, #061a3f 0%, #0b3ea8 34%, #155eef 70%, #9fd4ff 100%);
  --qtb-tide-cyan:  radial-gradient(circle, rgba(0, 194, 184, 0.56), transparent 66%);
  --qtb-tide-amber: radial-gradient(circle, rgba(244, 176, 94, 0.48), transparent 66%);
}

body {
  color: var(--qtb-text);
  background:
    radial-gradient(circle at 90% -4%, rgba(0, 194, 184, 0.15), transparent 38%),
    radial-gradient(circle at 8% 2%, rgba(15, 111, 255, 0.12), transparent 34%),
    linear-gradient(180deg, #fbfdff 0%, var(--qtb-bg) 48%, #e2f2f8 100%);
}

.qtb-header {
  background: rgba(250, 253, 255, 0.88);
  border-bottom-color: rgba(85, 183, 230, 0.22);
  backdrop-filter: blur(18px) saturate(1.18);
}

.qtb-brand__mark {
  background:
    radial-gradient(circle at 70% 22%, rgba(0, 194, 184, 0.80), transparent 35%),
    linear-gradient(145deg, #061a3f 0%, #155eef 58%, #18c9d2 100%);
  box-shadow: 0 12px 26px rgba(15, 111, 255, 0.26);
}

.qtb-brand__name {
  background: linear-gradient(95deg, var(--qtb-ink) 25%, var(--qtb-primary) 58%, var(--qtb-cyan));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.qtb-btn--primary {
  background: linear-gradient(135deg, #155eef 0%, #2f7cff 48%, #18c9d2 100%);
  box-shadow: 0 18px 34px rgba(15, 111, 255, 0.26);
}

.qtb-btn--primary::before {
  background: linear-gradient(135deg, #0b3ea8 0%, #061a3f 100%);
}

.qtb-btn--ghost {
  background: rgba(255, 255, 255, 0.82);
  border-color: rgba(85, 183, 230, 0.34);
}

.qtb-hero__panel,
.qtb-cta-strip {
  box-shadow:
    0 34px 90px rgba(6, 32, 63, 0.30),
    inset 0 1px 0 rgba(255, 255, 255, 0.20);
}

.qtb-hero__panel::before {
  background-image:
    radial-gradient(circle at 12% 18%, rgba(255, 255, 255, 0.20) 0 1px, transparent 1.5px),
    radial-gradient(circle at 76% 40%, rgba(255, 255, 255, 0.16) 0 1px, transparent 1.5px),
    linear-gradient(120deg, rgba(139, 216, 255, 0.14), transparent 42%),
    repeating-linear-gradient(100deg, rgba(255, 255, 255, 0.10) 0 1px, transparent 1px 28px);
  opacity: 0.92;
}

.qtb-hero__title em {
  background: linear-gradient(96deg, #ffffff 0%, #8bd8ff 30%, #00c2b8 62%, #fff1dc 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.qtb-hero__chip,
.qtb-hero__widget {
  background: rgba(6, 32, 63, 0.26);
  border-color: rgba(216, 235, 255, 0.26);
}

.qtb-cap-card,
.qtb-download-card,
.qtb-plan-card,
.qtb-faq-item,
.qtb-blog-card {
  border-color: rgba(85, 183, 230, 0.22);
}

.qtb-cap-card::before {
  background: linear-gradient(180deg, #22d3ee, #1261ff 58%, #c8ff5a);
}

.qtb-plan-card--featured {
  background:
    linear-gradient(#fff, #fff) padding-box,
    linear-gradient(135deg, #22d3ee, #1261ff 52%, #c8ff5a) border-box;
}

.qtb-plan-badge--accent,
.qtb-billing-switch button.is-active {
  background: linear-gradient(135deg, #18c9d2, #155eef 56%, #2f7cff);
}

.qtb-page-banner {
  background:
    radial-gradient(circle at 84% 18%, rgba(0, 194, 184, 0.20), transparent 38%),
    radial-gradient(circle at 12% 18%, rgba(244, 176, 94, 0.16), transparent 34%),
    linear-gradient(180deg, #fbfdff, #edf7fb);
}

.qtb-footer {
  background:
    radial-gradient(circle at 86% 0%, rgba(0, 194, 184, 0.12), transparent 32%),
    linear-gradient(180deg, transparent, rgba(15, 111, 255, 0.08));
}

.qtb-wing-badge::before {
  background:
    radial-gradient(circle at 35% 32%, #fff1dc 0%, transparent 60%),
    radial-gradient(circle at 70% 68%, #00c2b8 0%, transparent 60%),
    var(--qtb-primary);
  box-shadow: 0 0 0 2px rgba(15, 111, 255, 0.20);
}

/* =============================================================================
 * 28 · Legacy visual layer
 * ---------------------------------------------------------------------------
 * 保留 qtb-* 类名以兼容模板，同时用深海蓝、冰青和柠檬电光重塑可见界面。
 * ============================================================================= */

:root {
  --qtb-bg:           #eef4ff;
  --qtb-bg-alt:       #e0e7ff;
  --qtb-surface:      #ffffff;
  --qtb-surface-soft: #f5f8ff;
  --qtb-surface-deep: #07111f;

  --qtb-ink:        #08111f;
  --qtb-ink-soft:   #172554;
  --qtb-text:       #18315f;
  --qtb-text-soft:  #52627a;
  --qtb-text-faint: #8ea0bb;

  --qtb-primary:        #2563eb;
  --qtb-primary-strong: #1d4ed8;
  --qtb-primary-soft:   #dbeafe;
  --qtb-primary-deep:   #07111f;
  --qtb-secondary:      #4f46e5;
  --qtb-azure:          #7dd3fc;

  --qtb-cyan:           #22d3ee;
  --qtb-cyan-strong:    #0891b2;
  --qtb-cyan-soft:      #cffafe;

  --qtb-amber:          #818cf8;
  --qtb-amber-strong:   #4338ca;
  --qtb-amber-soft:     #e0e7ff;

  --qtb-border:        #c7d2fe;
  --qtb-border-strong: #60a5fa;
  --qtb-shadow-xs: 0 1px 2px rgba(37, 99, 235, 0.08);
  --qtb-shadow-sm: 0 2px 16px rgba(37, 99, 235, 0.13);
  --qtb-shadow:    0 24px 56px rgba(30, 64, 175, 0.18);
  --qtb-shadow-lg: 0 42px 90px rgba(7, 17, 31, 0.34);
  --qtb-glow:      0 0 0 6px rgba(34, 211, 238, 0.16),
                  0 18px 38px rgba(79, 70, 229, 0.28);
  --qtb-glow-amber: 0 0 0 6px rgba(129, 140, 248, 0.18),
                   0 18px 38px rgba(34, 211, 238, 0.22);

  --qtb-hero-grad:
    radial-gradient(ellipse 62% 72% at 84% 8%, rgba(34, 211, 238, 0.46), transparent 58%),
    radial-gradient(circle at 16% 18%, rgba(129, 140, 248, 0.36), transparent 46%),
    radial-gradient(circle at 52% 104%, rgba(37, 99, 235, 0.42), transparent 54%),
    linear-gradient(145deg, #07111f 0%, #172554 35%, #2563eb 72%, #38bdf8 100%);
  --qtb-tide-cyan:  radial-gradient(circle, rgba(34, 211, 238, 0.58), transparent 65%);
  --qtb-tide-amber: radial-gradient(circle, rgba(129, 140, 248, 0.50), transparent 65%);
}

body {
  color: var(--qtb-text);
  background:
    radial-gradient(circle at 92% 0%, rgba(34, 211, 238, 0.16), transparent 38%),
    radial-gradient(circle at 8% 8%, rgba(79, 70, 229, 0.13), transparent 34%),
    linear-gradient(180deg, #f8fbff 0%, var(--qtb-bg) 46%, #eaf1ff 100%);
}

.qtb-header {
  background: rgba(248, 251, 255, 0.84);
  border-bottom-color: rgba(96, 165, 250, 0.18);
  backdrop-filter: blur(18px) saturate(1.25);
}

.qtb-brand__mark {
  background:
    radial-gradient(circle at 70% 24%, rgba(34, 211, 238, 0.72), transparent 36%),
    linear-gradient(145deg, #07111f 0%, #1d4ed8 58%, #4f46e5 100%);
  box-shadow: 0 12px 24px rgba(37, 99, 235, 0.28);
}

.qtb-btn--primary {
  background: linear-gradient(135deg, #2563eb 0%, #4f46e5 48%, #0891b2 100%);
  box-shadow: 0 18px 34px rgba(37, 99, 235, 0.28);
}

.qtb-btn--ghost {
  background: rgba(255, 255, 255, 0.78);
  border-color: rgba(96, 165, 250, 0.32);
}

.qtb-hero__panel,
.qtb-cta-strip {
  box-shadow:
    0 34px 90px rgba(7, 17, 31, 0.30),
    inset 0 1px 0 rgba(255, 255, 255, 0.18);
}

.qtb-hero__panel::before {
  background-image:
    radial-gradient(circle at 10% 20%, rgba(255, 255, 255, 0.22) 0 1px, transparent 1.5px),
    radial-gradient(circle at 72% 42%, rgba(255, 255, 255, 0.18) 0 1px, transparent 1.5px),
    linear-gradient(120deg, rgba(125, 211, 252, 0.12), transparent 42%),
    repeating-linear-gradient(115deg, rgba(255, 255, 255, 0.10) 0 1px, transparent 1px 24px);
  opacity: 0.92;
}

.qtb-hero__title em {
  background: linear-gradient(96deg, #ffffff 0%, #7dd3fc 34%, #c4b5fd 72%, #ffffff 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.qtb-hero__chip,
.qtb-hero__widget {
  background: rgba(7, 17, 31, 0.24);
  border-color: rgba(191, 219, 254, 0.24);
}

.qtb-cap-card,
.qtb-download-card,
.qtb-plan-card,
.qtb-faq-item,
.qtb-blog-card {
  border-color: rgba(99, 102, 241, 0.18);
}

.qtb-cap-card::before {
  background: linear-gradient(180deg, #22d3ee, #2563eb 55%, #818cf8);
}

.qtb-plan-card--featured {
  background:
    linear-gradient(#fff, #fff) padding-box,
    linear-gradient(135deg, #22d3ee, #2563eb 48%, #818cf8) border-box;
}

.qtb-plan-badge--accent,
.qtb-billing-switch button.is-active {
  background: linear-gradient(135deg, #22d3ee, #2563eb 55%, #4f46e5);
}

.qtb-page-banner {
  background:
    radial-gradient(circle at 82% 18%, rgba(34, 211, 238, 0.22), transparent 38%),
    radial-gradient(circle at 16% 12%, rgba(129, 140, 248, 0.22), transparent 34%),
    linear-gradient(180deg, #f8fbff, #eef4ff);
}

.qtb-footer {
  background:
    radial-gradient(circle at 86% 0%, rgba(34, 211, 238, 0.12), transparent 32%),
    linear-gradient(180deg, transparent, rgba(37, 99, 235, 0.08));
}

/* =============================================================================
 * 00 · Legacy design tokens duplicate
 * ---------------------------------------------------------------------------
 * 本节为变量兜底副本，最终视觉由文件末尾 BlueHarbor Nova 覆盖层接管。
 * ============================================================================= */

:root {
  --qtb-bg:           #eaf8ff;
  --qtb-bg-alt:       #cfefff;
  --qtb-surface:      #ffffff;
  --qtb-surface-soft: #f2fbff;
  --qtb-surface-deep: #04154a;

  --qtb-ink:        #04154a;
  --qtb-ink-soft:   #124f88;
  --qtb-text:       #24506b;
  --qtb-text-soft:  #5f7f94;
  --qtb-text-faint: #9db8c9;

  --qtb-primary:        #0b5cff;
  --qtb-primary-strong: #0646c8;
  --qtb-primary-soft:   #dff1ff;
  --qtb-primary-deep:   #04154a;
  --qtb-secondary:      #00a7ff;
  --qtb-azure:          #b9efff;

  --qtb-cyan:           #2dd4ff;
  --qtb-cyan-strong:    #087fa6;
  --qtb-cyan-soft:      #d9f7ff;

  --qtb-amber:          #35f0b4;
  --qtb-amber-strong:   #c84a16;
  --qtb-amber-soft:     #fff1e8;

  /* —— signal · 语义色（v17 与冷辅 teal / 暖辅 orange 显式区隔，避免视觉撞色） —— */
  --qtb-success: #059669;        /* emerald-600 · 潮苗翠绿（与 teal 同青系但更绿） */
  --qtb-warn:    #d97706;        /* amber-600 · 警示金（与 orange 色相隔 12° 但彩度更黄） */
  --qtb-danger:  #dc2626;        /* red-600 · 紧急猩红（与 orange 区分仅靠彩度，仅用于关键场景） */

  /* —— borders & shadows · 潮霁雾青阴影族（v17 由深渊墨蓝 → 深渊墨蓝） —— */
  --qtb-border:        #a9dfff;
  --qtb-border-strong: #6fc7ff;
  --qtb-shadow-xs: 0 1px 2px rgba(11, 107, 255, 0.06);
  --qtb-shadow-sm: 0 2px 14px rgba(11, 107, 255, 0.11);
  --qtb-shadow:    0 18px 44px rgba(11, 107, 255, 0.18);
  --qtb-shadow-lg: 0 36px 80px rgba(6, 33, 63, 0.32);
  --qtb-glow:      0 0 0 6px rgba(11, 107, 255, 0.16),
                  0 14px 32px rgba(45, 212, 255, 0.28);
  --qtb-glow-amber: 0 0 0 6px rgba(11, 107, 255, 0.13),
                   0 14px 32px rgba(255, 138, 76, 0.26);

  /* BlueHarbor Nova archived hero gradient */
  --qtb-hero-grad:
    radial-gradient(ellipse 72% 78% at 88% 12%, rgba(45, 212, 255, 0.40), transparent 56%),
    radial-gradient(circle at 14% 86%, rgba(255, 138, 76, 0.22), transparent 58%),
    linear-gradient(158deg, #04154a 0%, #06266d 40%, #0b5cff 72%, #8be8ff 100%);
  --qtb-tide-cyan:  radial-gradient(circle, rgba(45, 212, 255, 0.50), transparent 65%);
  --qtb-tide-amber: radial-gradient(circle, rgba(255, 138, 76, 0.38), transparent 65%);

  /* —— radius scale —— */
  --qtb-radius-xs: 8px;
  --qtb-radius-sm: 12px;
  --qtb-radius:    18px;
  --qtb-radius-lg: 26px;
  --qtb-radius-xl: 36px;
  --qtb-pill:      999px;

  /* —— layout —— */
  --qtb-container: 1180px;
  --qtb-gutter:    24px;

  /* —— motion —— */
  --qtb-ease:     cubic-bezier(0.32, 0.72, 0, 1);
  --qtb-ease-out: cubic-bezier(0.2, 0.9, 0.3, 1);
  --qtb-tx-xs:    0.18s var(--qtb-ease);
  --qtb-tx-sm:    0.26s var(--qtb-ease);
  --qtb-tx-md:    0.42s var(--qtb-ease);
  --qtb-tx-lg:    0.72s var(--qtb-ease-out);

  /* —— typography —— */
  --qtb-font:
    -apple-system, BlinkMacSystemFont, "Segoe UI Variable", "Segoe UI", Inter,
    Roboto, "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB",
    Helvetica, Arial, sans-serif;
  --qtb-font-mono:
    "JetBrains Mono", "Cascadia Code", ui-monospace, "SFMono-Regular",
    "Roboto Mono", monospace;
}

/* =============================================================================
 * 01 · Reset & base
 * ============================================================================= */

*,
*::before,
*::after { box-sizing: border-box; }

html {
  scroll-behavior: smooth;
  text-size-adjust: 100%;
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  font-family: var(--qtb-font);
  font-size: 16px;
  color: var(--qtb-text);
  background: var(--qtb-bg);
  /* BlueHarbor Nova archived 三轴微光 */
  background-image:
    radial-gradient(circle at 96% -4%,  rgba(45, 212, 255, 0.16), transparent 42%),
    radial-gradient(circle at 4% 6%,    rgba(11, 107, 255, 0.12), transparent 40%),
    radial-gradient(circle at 50% 108%, rgba(255, 138, 76, 0.14), transparent 50%);
  background-attachment: fixed;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

body.qtb-no-scroll { overflow: hidden; }

a { color: inherit; text-decoration: none; }
a[role="link"] { cursor: pointer; }

img,
svg { max-width: 100%; display: block; }

button { font-family: inherit; }

::selection {
  background: var(--qtb-cyan);
  color: #fff;
}

:focus-visible {
  outline: 3px solid var(--qtb-amber);
  outline-offset: 2px;
}

/* =============================================================================
 * 02 · Layout primitives
 * ============================================================================= */

.qtb-shell {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  overflow-x: clip;
}

.qtb-container {
  width: min(92%, var(--qtb-container));
  margin-inline: auto;
}

.qtb-main { flex: 1; }

.qtb-section { padding: 96px 0; }
.qtb-section--tight { padding-top: 32px; }
.qtb-section--alt {
  position: relative;
  background:
    linear-gradient(180deg, rgba(3, 105, 161, 0.05), transparent 55%),
    linear-gradient(180deg, rgba(20, 184, 166, 0.05), transparent 85%);
}

.qtb-section-head {
  text-align: center;
  max-width: 820px;
  margin: 0 auto 50px;
}

/* eyebrow · 深青软底 + 潮翡灯辉带渐变线 */
.qtb-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 0.76rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--qtb-primary-strong);
  background: linear-gradient(90deg, var(--qtb-primary-soft), #fff 70%);
  border: 1px solid rgba(3, 105, 161, 0.20);
  border-radius: var(--qtb-pill);
  padding: 7px 16px 7px 10px;
  margin: 0 0 16px;
}

.qtb-eyebrow::before {
  content: "";
  width: 14px;
  height: 2px;
  border-radius: 2px;
  background: linear-gradient(90deg, var(--qtb-primary), var(--qtb-cyan));
  box-shadow: 0 0 0 3px rgba(20, 184, 166, 0.18);
}

.qtb-section-head h2 {
  margin: 0 0 14px;
  font-size: clamp(1.65rem, 3.2vw, 2.4rem);
  letter-spacing: -0.01em;
  color: var(--qtb-ink);
  line-height: 1.22;
}

.qtb-section-head p {
  margin: 0;
  color: var(--qtb-text-soft);
  font-size: 1.04rem;
}

/* 渐变文字 · 深青 → 潮翡灯辉 → 丹橘焰辉 */
.qtb-gradient-text {
  background: linear-gradient(95deg, var(--qtb-primary) 12%, var(--qtb-cyan) 55%, var(--qtb-amber));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  color: transparent;
}

/* —— 屏幕阅读器专用文本 —— */
.qtb-sr {
  position: absolute !important;
  clip: rect(1px, 1px, 1px, 1px);
  width: 1px;
  height: 1px;
  overflow: hidden;
  white-space: nowrap;
}

/* —— 跳过到主内容 · a11y —— */
.qtb-skip {
  position: absolute;
  top: -40px;
  left: 12px;
  background: var(--qtb-primary);
  color: #fff;
  padding: 10px 16px;
  border-radius: var(--qtb-radius-sm);
  z-index: 999;
  transition: top 0.2s var(--qtb-ease);
}

.qtb-skip:focus { top: 12px; }

/* =============================================================================
 * 03 · Header & Navigation
 * ============================================================================= */

.qtb-header {
  position: sticky;
  top: 0;
  z-index: 60;
  background: rgba(244, 245, 251, 0.80);
  backdrop-filter: blur(18px) saturate(170%);
  -webkit-backdrop-filter: blur(18px) saturate(170%);
  border-bottom: 1px solid transparent;
  transition: border-color var(--qtb-tx-xs), box-shadow var(--qtb-tx-xs),
              background var(--qtb-tx-xs);
}

.qtb-header.is-pinned {
  border-bottom-color: rgba(3, 105, 161, 0.16);
  box-shadow: var(--qtb-shadow-sm);
  background: rgba(255, 255, 255, 0.96);
}

.qtb-header__inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 24px;
  min-height: 74px;
}

.qtb-brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  font-weight: 700;
  font-size: 1.1rem;
  white-space: nowrap;
  color: var(--qtb-ink);
}

/* logo 容器 · 深海蓝 + 右上冰青灯辉 + 左下柠檬电光 */
.qtb-brand__mark {
  width: 40px;
  height: 40px;
  flex-shrink: 0;
  border-radius: 12px;
  background: linear-gradient(150deg, #04154a 0%, #073bb5 52%, #00a7ff 100%);
  padding: 7px;
  display: grid;
  place-items: center;
  box-shadow: 0 8px 22px rgba(11, 107, 255, 0.36);
  position: relative;
  overflow: hidden;
}

.qtb-brand__mark::after {
  content: "";
  position: absolute;
  inset: 0;
  background:
    radial-gradient(circle at 80% 20%, rgba(45, 212, 255, 0.55), transparent 55%),
    radial-gradient(circle at 20% 78%, rgba(255, 138, 76, 0.42), transparent 55%);
  pointer-events: none;
}

.qtb-brand__mark img,
.qtb-brand__mark svg {
  width: 100%;
  height: 100%;
  position: relative;
  z-index: 1;
}

.qtb-brand__name {
  background: linear-gradient(95deg, var(--qtb-ink) 30%, var(--qtb-primary) 65%, var(--qtb-cyan));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  color: transparent;
}

.qtb-nav { display: flex; }

.qtb-nav ul,
.qtb-mobile-nav ul {
  display: flex;
  gap: 4px;
  list-style: none;
  padding: 0;
  margin: 0;
}

.qtb-nav a {
  display: inline-flex;
  align-items: center;
  color: var(--qtb-text-soft);
  font-weight: 500;
  font-size: 0.95rem;
  padding: 9px 14px;
  border-radius: var(--qtb-radius-sm);
  transition: color var(--qtb-tx-xs), background var(--qtb-tx-xs);
  position: relative;
}

.qtb-nav a:hover,
.qtb-nav a:focus-visible,
.qtb-nav a[aria-current] {
  color: var(--qtb-primary-strong);
  background: var(--qtb-primary-soft);
}

/* 当前页指示：底部 2px 冰青 → 柠檬电光渐变线 */
.qtb-nav a[aria-current]::after {
  content: "";
  position: absolute;
  left: 14px; right: 14px; bottom: 4px;
  height: 2px;
  border-radius: 2px;
  background: linear-gradient(90deg, var(--qtb-cyan), var(--qtb-amber));
}

.qtb-header__actions {
  display: flex;
  align-items: center;
  gap: 10px;
}

.qtb-menu-toggle {
  display: none;
  border: 1px solid var(--qtb-border);
  background: var(--qtb-surface);
  color: var(--qtb-ink);
  border-radius: var(--qtb-radius-sm);
  font-weight: 600;
  padding: 9px 14px;
  cursor: pointer;
  transition: background var(--qtb-tx-xs), border-color var(--qtb-tx-xs);
}

.qtb-menu-toggle:hover {
  background: var(--qtb-primary-soft);
  border-color: var(--qtb-primary);
}

/* —— 移动端抽屉 —— */
.qtb-mobile-overlay {
  position: fixed;
  inset: 0;
  z-index: 110;
  background: rgba(8, 47, 73, 0.55);
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--qtb-tx-md);
  backdrop-filter: blur(4px);
}

.qtb-mobile-overlay.is-shown {
  opacity: 1;
  pointer-events: auto;
}

.qtb-mobile-panel {
  position: fixed;
  top: 0;
  right: 0;
  width: min(82vw, 380px);
  height: 100vh;
  z-index: 120;
  background: var(--qtb-surface);
  border-left: 1px solid var(--qtb-border);
  box-shadow: -28px 0 70px rgba(8, 47, 73, 0.3);
  transform: translate3d(108%, 0, 0);
  visibility: hidden;
  pointer-events: none;
  will-change: transform;
  transition: transform 0.46s var(--qtb-ease),
              visibility 0s linear 0.46s;
  padding: 22px 0;
  touch-action: pan-y;
}

.qtb-mobile-panel.is-shown {
  transform: translate3d(0, 0, 0);
  visibility: visible;
  pointer-events: auto;
  transition: transform 0.46s var(--qtb-ease),
              visibility 0s linear 0s;
}

.qtb-mobile-panel__head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 20px;
}

.qtb-mobile-close {
  width: 38px;
  height: 38px;
  border-radius: var(--qtb-radius-sm);
  border: 1px solid var(--qtb-border);
  background: var(--qtb-surface);
  color: var(--qtb-ink);
  font-size: 1.2rem;
  cursor: pointer;
}

.qtb-mobile-nav ul {
  flex-direction: column;
  gap: 8px;
}

.qtb-mobile-nav a {
  display: block;
  border: 1px solid var(--qtb-border);
  border-radius: var(--qtb-radius-sm);
  padding: 13px 15px;
  color: var(--qtb-text);
  font-weight: 500;
  transition: background var(--qtb-tx-xs), border-color var(--qtb-tx-xs);
}

.qtb-mobile-nav a:hover {
  background: var(--qtb-primary-soft);
  border-color: var(--qtb-primary);
  color: var(--qtb-primary-strong);
}

.qtb-mobile-cta {
  display: flex;
  width: 100%;
  margin-top: 18px;
}

/* =============================================================================
 * 04 · Buttons（深青主轴 + 潮翡灯辉强调按钮 + 丹橘焰辉朝霞光晕）
 * ============================================================================= */

.qtb-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  border-radius: var(--qtb-radius-sm);
  border: 1px solid transparent;
  padding: 13px 24px;
  font-weight: 600;
  font-size: 0.97rem;
  letter-spacing: 0.01em;
  transition: transform var(--qtb-tx-xs), background var(--qtb-tx-xs),
              color var(--qtb-tx-xs), border-color var(--qtb-tx-xs),
              box-shadow var(--qtb-tx-xs);
  cursor: pointer;
  text-align: center;
  white-space: nowrap;
  position: relative;
  overflow: hidden;
  isolation: isolate;
}

.qtb-btn:focus-visible {
  outline: 3px solid var(--qtb-amber);
  outline-offset: 2px;
}

/* 主按钮 · 渊海墨青 → 深渊墨蓝；hover 在右下绽放潮翡灯辉光晕 */
.qtb-btn--primary {
  background: linear-gradient(135deg, var(--qtb-primary) 0%, var(--qtb-primary-strong) 100%);
  color: #fff;
  box-shadow: 0 10px 26px rgba(3, 105, 161, 0.40);
}

.qtb-btn--primary::before {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, var(--qtb-primary-strong) 0%, var(--qtb-primary-deep) 100%);
  opacity: 0;
  transition: opacity var(--qtb-tx-xs);
  z-index: -1;
}

.qtb-btn--primary::after {
  content: "";
  position: absolute;
  width: 80%;
  height: 220%;
  right: -25%;
  bottom: -140%;
  background: radial-gradient(ellipse, rgba(20, 184, 166, 0.55), transparent 70%);
  opacity: 0;
  transition: opacity var(--qtb-tx-md), transform var(--qtb-tx-md);
  z-index: -1;
}

.qtb-btn--primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 18px 36px rgba(3, 105, 161, 0.46),
              0 8px 22px rgba(20, 184, 166, 0.32);
}

.qtb-btn--primary:hover::before { opacity: 1; }
.qtb-btn--primary:hover::after  { opacity: 1; transform: translate(-18%, -12%); }

/* 潮翡灯辉强调按钮 · 用于二级强 CTA */
.qtb-btn--cyan {
  background: linear-gradient(135deg, var(--qtb-cyan) 0%, var(--qtb-cyan-strong) 100%);
  color: #fff;
  box-shadow: 0 10px 26px rgba(20, 184, 166, 0.42);
}

.qtb-btn--cyan:hover {
  transform: translateY(-2px);
  box-shadow: 0 18px 36px rgba(20, 184, 166, 0.52);
  filter: brightness(1.04);
}

/* 幽灵按钮 · 描边 + hover 深青填充 */
.qtb-btn--ghost {
  background: var(--qtb-surface);
  color: var(--qtb-ink);
  border-color: var(--qtb-border);
}

.qtb-btn--ghost:hover {
  border-color: var(--qtb-primary);
  color: var(--qtb-primary-strong);
  background: var(--qtb-primary-soft);
  transform: translateY(-1px);
}

/* 暗底反白按钮 · hero 内使用 */
.qtb-btn--on-dark {
  background: rgba(255, 255, 255, 0.10);
  color: #fff;
  border-color: rgba(255, 255, 255, 0.32);
  backdrop-filter: blur(6px);
}

.qtb-btn--on-dark:hover {
  background: #fff;
  color: var(--qtb-primary-strong);
}

.qtb-btn--inverted {
  background: #fff;
  color: var(--qtb-primary-strong);
}

.qtb-btn--inverted:hover {
  background: var(--qtb-cyan-soft);
  color: var(--qtb-cyan-strong);
}

.qtb-btn--lg {
  padding: 15px 30px;
  font-size: 1.02rem;
  border-radius: var(--qtb-radius);
}

/* =============================================================================
 * 05 · Hero — 灯塔光徽面板
 * ============================================================================= */

.qtb-hero { padding: 56px 0 36px; }

.qtb-hero__panel {
  position: relative;
  border-radius: var(--qtb-radius-xl);
  padding: 72px 60px;
  background: var(--qtb-hero-grad);
  color: #fff;
  overflow: hidden;
  box-shadow: var(--qtb-shadow-lg);
  isolation: isolate;
}

/* hero 背景：深海微光 + 海图经线条纹 */
.qtb-hero__panel::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    radial-gradient(1.2px 1.2px at 14% 22%,   rgba(255,255,255,0.85), transparent),
    radial-gradient(1px 1px   at 76% 18%,     rgba(255,255,255,0.65), transparent),
    radial-gradient(1.4px 1.4px at 36% 64%,   rgba(255,255,255,0.80), transparent),
    radial-gradient(1px 1px   at 62% 78%,     rgba(255,255,255,0.55), transparent),
    radial-gradient(1.6px 1.6px at 88% 48%,   rgba(255,255,255,0.85), transparent),
    radial-gradient(1px 1px   at 22% 86%,     rgba(255,255,255,0.50), transparent),
    repeating-linear-gradient(
      115deg,
      rgba(255, 255, 255, 0.035) 0,
      rgba(255, 255, 255, 0.035) 1px,
      transparent 1px,
      transparent 44px
    );
  mask-image: linear-gradient(180deg, rgba(0, 0, 0, 0.85), rgba(0, 0, 0, 0.5));
  -webkit-mask-image: linear-gradient(180deg, rgba(0, 0, 0, 0.85), rgba(0, 0, 0, 0.5));
  pointer-events: none;
}

/* hero 右上"冰青灯辉"光斑 */
.qtb-hero__panel::after {
  content: "";
  position: absolute;
  width: 620px;
  height: 620px;
  right: -180px;
  top: -260px;
  border-radius: 50%;
  background: var(--qtb-tide-cyan);
  pointer-events: none;
  z-index: 0;
}

/* hero 左下"柠檬电光"光斑（与蓝色主轴形成对角张力） */
.qtb-hero__panel > .qtb-glow-amber {
  position: absolute;
  width: 380px;
  height: 380px;
  left: -130px;
  bottom: -140px;
  border-radius: 50%;
  background: var(--qtb-tide-amber);
  pointer-events: none;
  z-index: 0;
}

/* hero 右上"罗盘校准线"光痕 */
.qtb-hero__panel > .qtb-beacon {
  position: absolute;
  width: 110px;
  height: 110px;
  right: 8%;
  top: 14%;
  pointer-events: none;
  z-index: 0;
  opacity: 0.9;
}

.qtb-hero__panel > .qtb-beacon::before,
.qtb-hero__panel > .qtb-beacon::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(90deg, transparent 0%, rgba(255, 255, 255, 0.85) 50%, transparent 100%);
  filter: blur(0.4px);
}

.qtb-hero__panel > .qtb-beacon::before {
  height: 1.5px;
  top: 50%;
  transform: translateY(-50%);
  box-shadow: 0 0 10px rgba(45, 212, 255, 0.85);
  animation: qmBeaconHorz 2.6s ease-in-out infinite;
}

.qtb-hero__panel > .qtb-beacon::after {
  width: 1.5px;
  left: 50%;
  transform: translateX(-50%);
  background: linear-gradient(180deg, transparent 0%, rgba(255, 255, 255, 0.85) 50%, transparent 100%);
  box-shadow: 0 0 10px rgba(255, 138, 76, 0.85);
  animation: qmBeaconVert 2.6s ease-in-out infinite;
}

@keyframes qmBeaconHorz {
  0%, 100% { opacity: 0.6; transform: translateY(-50%) scaleX(1);   }
  50%      { opacity: 1;   transform: translateY(-50%) scaleX(1.4); }
}

@keyframes qmBeaconVert {
  0%, 100% { opacity: 0.6; transform: translateX(-50%) scaleY(1);   }
  50%      { opacity: 1;   transform: translateX(-50%) scaleY(1.4); }
}

.qtb-hero__grid {
  position: relative;
  display: grid;
  gap: 44px;
  grid-template-columns: 1.15fr 1fr;
  align-items: center;
  z-index: 1;
}

.qtb-hero__eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-weight: 700;
  font-size: 0.78rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: #a5f3fc;
  border: 1px solid rgba(255, 255, 255, 0.30);
  border-radius: var(--qtb-pill);
  padding: 7px 16px 7px 12px;
  margin: 0 0 22px;
  background: rgba(255, 255, 255, 0.06);
  backdrop-filter: blur(6px);
}

.qtb-hero__eyebrow::before {
  content: "";
  width: 14px;
  height: 2px;
  border-radius: 2px;
  background: linear-gradient(90deg, var(--qtb-cyan), var(--qtb-amber));
  box-shadow: 0 0 0 3px rgba(20, 184, 166, 0.30);
}

.qtb-hero__title {
  margin: 0 0 20px;
  font-size: clamp(2.1rem, 4.8vw, 3.3rem);
  line-height: 1.14;
  letter-spacing: -0.025em;
  font-weight: 800;
}

/* 高亮词 · 潮翡灯辉 → 丹橘焰辉（冷暖反相） */
.qtb-hero__title em {
  font-style: normal;
  background: linear-gradient(95deg, #fdba74 0%, #67e8f9 28%, #fdba74 76%, #ffffff 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  color: transparent;
}

.qtb-hero__lead {
  margin: 0 0 32px;
  color: rgba(255, 255, 255, 0.86);
  font-size: 1.08rem;
  max-width: 560px;
  line-height: 1.7;
}

.qtb-hero__cta-row {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
}

.qtb-hero__chips {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 24px;
}

.qtb-hero__chip {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  border: 1px solid rgba(255, 255, 255, 0.22);
  background: rgba(255, 255, 255, 0.08);
  border-radius: var(--qtb-pill);
  padding: 8px 14px;
  font-size: 0.86rem;
  color: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(4px);
}

.qtb-hero__chip::before {
  content: "";
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--qtb-amber);
  box-shadow: 0 0 0 4px rgba(249, 115, 22, 0.30);
}

/* hero 右侧实时面板 · 毛玻璃 + 深青→翡青→丹橘渐变描边 */
.qtb-hero__widget {
  background: rgba(255, 255, 255, 0.08);
  border: 1px solid rgba(255, 255, 255, 0.18);
  backdrop-filter: blur(10px);
  border-radius: var(--qtb-radius);
  padding: 24px;
  position: relative;
  overflow: hidden;
}

.qtb-hero__widget::before {
  content: "";
  position: absolute;
  inset: -1px;
  border-radius: inherit;
  padding: 1px;
  background: linear-gradient(135deg,
    rgba(3, 105, 161, 0.55) 0%,
    rgba(20, 184, 166, 0.60) 50%,
    rgba(249, 115, 22, 0.55) 100%);
  -webkit-mask:
    linear-gradient(#fff 0 0) content-box,
    linear-gradient(#fff 0 0);
  -webkit-mask-composite: xor;
  mask-composite: exclude;
  pointer-events: none;
}

.qtb-hero__widget h2 {
  margin: 0 0 18px;
  font-size: 1.08rem;
  color: #fff;
  display: flex;
  align-items: center;
  gap: 8px;
}

.qtb-hero__widget h2::before {
  content: "";
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--qtb-amber);
  box-shadow: 0 0 0 4px rgba(249, 115, 22, 0.34);
  animation: qmTidePulse 1.8s ease-in-out infinite;
}

@keyframes qmTidePulse {
  0%, 100% { transform: scale(1);    opacity: 1;    }
  50%      { transform: scale(1.35); opacity: 0.55; }
}

.qtb-metric-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 12px;
}

.qtb-metric {
  border-radius: var(--qtb-radius-sm);
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid rgba(255, 255, 255, 0.14);
  padding: 14px 16px;
}

.qtb-metric small {
  display: block;
  color: rgba(255, 255, 255, 0.74);
  font-size: 0.8rem;
  margin-bottom: 4px;
}

.qtb-metric strong {
  display: block;
  font-size: 1.32rem;
  color: #fff;
  font-weight: 800;
}

/* =============================================================================
 * 06 · Trust strip / 信任 KPI 条
 * ============================================================================= */

.qtb-stats-strip { padding: 40px 0 16px; }

.qtb-stats-strip__grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 18px;
}

.qtb-stat-tile {
  background: var(--qtb-surface);
  border: 1px solid var(--qtb-border);
  border-radius: var(--qtb-radius);
  padding: 22px 22px;
  text-align: center;
  box-shadow: var(--qtb-shadow-sm);
  position: relative;
  overflow: hidden;
  transition: transform var(--qtb-tx-sm), box-shadow var(--qtb-tx-sm);
}

/* 悬停下方升起一根 深青→翡青→丹橘 三段渐变线 */
.qtb-stat-tile::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 50%;
  height: 3px;
  width: 0;
  border-radius: 3px 3px 0 0;
  background: linear-gradient(90deg, var(--qtb-primary), var(--qtb-cyan), var(--qtb-amber));
  transition: width var(--qtb-tx-md), left var(--qtb-tx-md);
}

.qtb-stat-tile:hover {
  transform: translateY(-3px);
  box-shadow: var(--qtb-shadow);
}

.qtb-stat-tile:hover::after {
  width: 70%;
  left: 15%;
}

.qtb-stat-tile strong {
  display: block;
  font-size: 1.45rem;
  color: var(--qtb-ink);
  font-weight: 800;
  letter-spacing: -0.01em;
}

.qtb-stat-tile span {
  color: var(--qtb-text-soft);
  font-size: 0.88rem;
}

/* =============================================================================
 * 07 · Card grids（功能 / 场景 / 帮助 / FAQ / 博客）
 * ============================================================================= */

.qtb-card-grid {
  display: grid;
  gap: 22px;
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

.qtb-cap-card,
.qtb-download-card,
.qtb-plan-card,
.qtb-faq-item,
.qtb-blog-card,
.qtb-help-card {
  background: var(--qtb-surface);
  border: 1px solid var(--qtb-border);
  border-radius: var(--qtb-radius);
  box-shadow: var(--qtb-shadow-xs);
  transition: transform var(--qtb-tx-md), border-color var(--qtb-tx-xs),
              box-shadow var(--qtb-tx-md);
}

.qtb-cap-card {
  padding: 28px 26px;
  position: relative;
  overflow: hidden;
}

/* 卡片 hover 左侧探出 3px 深青→翡青→丹橘渐变线 */
.qtb-cap-card::before {
  content: "";
  position: absolute;
  top: 16px;
  bottom: 16px;
  left: 0;
  width: 3px;
  border-radius: 0 3px 3px 0;
  background: linear-gradient(180deg, var(--qtb-primary), var(--qtb-cyan), var(--qtb-amber));
  transform: scaleY(0.2);
  transform-origin: top;
  opacity: 0;
  transition: transform var(--qtb-tx-md), opacity var(--qtb-tx-md);
}

.qtb-cap-card:hover {
  transform: translateY(-4px);
  border-color: rgba(3, 105, 161, 0.30);
  box-shadow: var(--qtb-shadow);
}

.qtb-cap-card:hover::before {
  transform: scaleY(1);
  opacity: 1;
}

.qtb-cap-card__icon {
  display: inline-grid;
  place-items: center;
  width: 46px;
  height: 46px;
  border-radius: 12px;
  background: linear-gradient(135deg, var(--qtb-primary-soft), var(--qtb-cyan-soft));
  font-size: 1.4rem;
  margin-bottom: 18px;
  box-shadow: 0 6px 14px rgba(3, 105, 161, 0.18);
}

.qtb-cap-card h3 {
  margin: 0 0 10px;
  font-size: 1.05rem;
  color: var(--qtb-ink);
}

.qtb-cap-card p {
  margin: 0;
  color: var(--qtb-text-soft);
  font-size: 0.94rem;
  line-height: 1.65;
}

/* =============================================================================
 * 08 · Plan cards / 订阅套餐 / 计费切换
 * ============================================================================= */

.qtb-billing-switch {
  display: inline-flex;
  align-items: center;
  margin: 0 auto 38px;
  background: var(--qtb-surface);
  border: 1px solid var(--qtb-border);
  border-radius: var(--qtb-pill);
  padding: 4px;
  gap: 4px;
  box-shadow: var(--qtb-shadow-xs);
}

.qtb-billing-switch button {
  border: 0;
  background: transparent;
  border-radius: var(--qtb-pill);
  padding: 9px 18px;
  font-size: 0.92rem;
  font-weight: 600;
  color: var(--qtb-text-soft);
  cursor: pointer;
  transition: background var(--qtb-tx-xs), color var(--qtb-tx-xs);
}

.qtb-billing-switch button.is-active {
  background: linear-gradient(135deg, var(--qtb-primary), var(--qtb-cyan));
  color: #fff;
  box-shadow: 0 6px 14px rgba(3, 105, 161, 0.32);
}

.qtb-plans {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 22px;
  align-items: stretch;
}

.qtb-plan-card {
  padding: 30px 28px;
  display: flex;
  flex-direction: column;
  gap: 12px;
  position: relative;
}

.qtb-plan-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--qtb-shadow);
  border-color: rgba(3, 105, 161, 0.30);
}

.qtb-plan-card__head {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
}

.qtb-plan-card h3 {
  margin: 0;
  font-size: 1.15rem;
  color: var(--qtb-ink);
}

.qtb-plan-card__note {
  margin: 0;
  color: var(--qtb-text-soft);
  font-size: 0.92rem;
  min-height: 38px;
}

.qtb-plan-card__price {
  margin: 6px 0 14px;
  font-weight: 800;
  font-size: 2.05rem;
  color: var(--qtb-ink);
  letter-spacing: -0.02em;
}

.qtb-plan-card__price span {
  font-size: 0.96rem;
  font-weight: 500;
  color: var(--qtb-text-soft);
  margin-left: 6px;
}

.qtb-plan-card ul {
  list-style: none;
  margin: 0 0 18px;
  padding: 0;
  flex: 1;
  display: grid;
  gap: 10px;
}

.qtb-plan-card li {
  position: relative;
  padding-left: 24px;
  font-size: 0.94rem;
  color: var(--qtb-text);
}

.qtb-plan-card li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 6px;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--qtb-primary-soft), var(--qtb-amber-soft));
  border: 1.6px solid var(--qtb-primary);
}

.qtb-plan-card li::after {
  content: "";
  position: absolute;
  left: 4px;
  top: 9px;
  width: 6px;
  height: 3px;
  border-left: 1.6px solid var(--qtb-primary);
  border-bottom: 1.6px solid var(--qtb-primary);
  transform: rotate(-45deg);
}

.qtb-plan-card .qtb-btn {
  width: 100%;
}

.qtb-plan-badge {
  display: inline-flex;
  align-items: center;
  background: var(--qtb-bg-alt);
  color: var(--qtb-text-soft);
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  padding: 4px 10px;
  border-radius: var(--qtb-pill);
  text-transform: uppercase;
}

.qtb-plan-badge--accent {
  background: linear-gradient(135deg, var(--qtb-cyan), var(--qtb-primary));
  color: #fff;
  box-shadow: 0 4px 10px rgba(20, 184, 166, 0.30);
}

/* 推荐套餐 · 渐变描边 + ribbon */
.qtb-plan-card--featured {
  border-color: transparent;
  background:
    linear-gradient(var(--qtb-surface), var(--qtb-surface)) padding-box,
    linear-gradient(140deg, var(--qtb-primary), var(--qtb-cyan) 60%, var(--qtb-amber)) border-box;
  border-width: 2px;
  border-style: solid;
  box-shadow: 0 18px 38px rgba(3, 105, 161, 0.22);
}

.qtb-plan-card--featured::after {
  content: attr(data-ribbon);
  position: absolute;
  top: -14px;
  right: 22px;
  background: linear-gradient(135deg, var(--qtb-cyan), var(--qtb-primary));
  color: #fff;
  font-size: 0.74rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  padding: 6px 14px;
  border-radius: var(--qtb-pill);
  box-shadow: 0 6px 14px rgba(20, 184, 166, 0.34);
}

/* =============================================================================
 * 09 · Comparison table
 * ============================================================================= */

.qtb-compare-wrap {
  background: var(--qtb-surface);
  border: 1px solid var(--qtb-border);
  border-radius: var(--qtb-radius);
  overflow: hidden;
  box-shadow: var(--qtb-shadow-sm);
  overflow-x: auto;
}

.qtb-compare-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.95rem;
}

.qtb-compare-table thead {
  background: linear-gradient(180deg, var(--qtb-primary-soft), transparent);
}

.qtb-compare-table th,
.qtb-compare-table td {
  padding: 16px 18px;
  text-align: left;
  border-bottom: 1px solid var(--qtb-border);
  vertical-align: top;
}

.qtb-compare-table thead th {
  font-weight: 700;
  color: var(--qtb-ink);
  font-size: 0.95rem;
}

.qtb-compare-table tbody th {
  font-weight: 600;
  color: var(--qtb-ink);
  background: var(--qtb-surface-soft);
  width: 30%;
}

.qtb-compare-table tbody tr:last-child th,
.qtb-compare-table tbody tr:last-child td {
  border-bottom: 0;
}

/* =============================================================================
 * 10 · Download cards
 * ============================================================================= */

.qtb-download-grid {
  display: grid;
  gap: 18px;
  grid-template-columns: repeat(5, minmax(0, 1fr));
}

.qtb-download-card {
  padding: 22px 20px;
  text-align: center;
  display: flex;
  flex-direction: column;
  gap: 6px;
  color: var(--qtb-text);
  position: relative;
  isolation: isolate;
  overflow: hidden;
}

.qtb-download-card::before {
  content: "";
  position: absolute;
  inset: -1px;
  border-radius: inherit;
  background: linear-gradient(135deg,
    rgba(3, 105, 161, 0) 0%,
    rgba(20, 184, 166, 0) 50%,
    rgba(249, 115, 22, 0) 100%);
  z-index: -1;
  transition: background var(--qtb-tx-md);
}

.qtb-download-card:hover {
  transform: translateY(-3px);
  border-color: rgba(3, 105, 161, 0.35);
  box-shadow: var(--qtb-shadow);
}

.qtb-download-card:hover::before {
  background: linear-gradient(135deg,
    rgba(3, 105, 161, 0.07) 0%,
    rgba(20, 184, 166, 0.05) 50%,
    rgba(249, 115, 22, 0.07) 100%);
}

.qtb-download-card__platform {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--qtb-ink);
}

.qtb-download-card__hint {
  color: var(--qtb-text-soft);
  font-size: 0.86rem;
}

/* =============================================================================
 * 11 · Testimonials carousel
 * ============================================================================= */

.qtb-testimonials {
  position: relative;
  overflow: hidden;
  padding: 4px;
}

.qtb-testimonials__track {
  display: flex;
  gap: 22px;
  transition: transform var(--qtb-tx-md);
}

.qtb-testimonial-card {
  flex: 0 0 calc((100% - 44px) / 3);
  background: var(--qtb-surface);
  border: 1px solid var(--qtb-border);
  border-radius: var(--qtb-radius);
  padding: 26px 24px;
  box-shadow: var(--qtb-shadow-xs);
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.qtb-testimonial-card p {
  margin: 0;
  color: var(--qtb-text);
  line-height: 1.7;
  font-size: 0.96rem;
}

.qtb-testimonial-card strong {
  color: var(--qtb-text-soft);
  font-weight: 600;
  font-size: 0.86rem;
}

.qtb-carousel-controls {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 18px;
  margin-top: 22px;
}

.qtb-carousel-arrow {
  width: 38px;
  height: 38px;
  border-radius: 50%;
  border: 1px solid var(--qtb-border);
  background: var(--qtb-surface);
  color: var(--qtb-ink);
  font-size: 1.1rem;
  cursor: pointer;
  transition: background var(--qtb-tx-xs), border-color var(--qtb-tx-xs);
}

.qtb-carousel-arrow:hover {
  background: var(--qtb-primary-soft);
  border-color: var(--qtb-primary);
  color: var(--qtb-primary-strong);
}

.qtb-carousel-dots {
  display: flex;
  gap: 8px;
}

.qtb-carousel-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  border: 0;
  padding: 0;
  background: var(--qtb-border-strong);
  cursor: pointer;
  transition: background var(--qtb-tx-xs), transform var(--qtb-tx-xs);
}

.qtb-carousel-dot.is-active {
  background: linear-gradient(135deg, var(--qtb-primary), var(--qtb-cyan));
  transform: scale(1.25);
}

/* =============================================================================
 * 12 · Step list（5-step quickstart）
 * ============================================================================= */

.qtb-step-list {
  list-style: none;
  padding: 0;
}

.qtb-step-list li {
  display: flex;
  gap: 16px;
  align-items: flex-start;
  background: var(--qtb-surface);
  border: 1px solid var(--qtb-border);
  border-radius: var(--qtb-radius);
  padding: 18px 22px;
  box-shadow: var(--qtb-shadow-xs);
}

.qtb-step-num {
  flex-shrink: 0;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  display: grid;
  place-items: center;
  font-weight: 800;
  color: #fff;
  background: linear-gradient(135deg, var(--qtb-primary), var(--qtb-cyan));
  box-shadow: 0 6px 14px rgba(3, 105, 161, 0.34);
}

.qtb-step-list strong {
  color: var(--qtb-ink);
}

/* =============================================================================
 * 13 · FAQ accordion
 * ============================================================================= */

.qtb-faq {
  display: grid;
  gap: 14px;
  max-width: 880px;
  margin: 0 auto;
}

.qtb-faq-item {
  padding: 0;
  overflow: hidden;
  transition: border-color var(--qtb-tx-xs), box-shadow var(--qtb-tx-xs);
}

.qtb-faq-item.is-open {
  border-color: rgba(3, 105, 161, 0.32);
  box-shadow: var(--qtb-shadow-sm);
}

.qtb-faq-question {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  border: 0;
  background: transparent;
  text-align: left;
  cursor: pointer;
  padding: 20px 22px;
  font: inherit;
  font-size: 1rem;
  font-weight: 600;
  color: var(--qtb-ink);
  transition: color var(--qtb-tx-xs);
}

.qtb-faq-question::after {
  content: "+";
  font-size: 1.4rem;
  color: var(--qtb-primary);
  transition: transform var(--qtb-tx-sm);
}

.qtb-faq-item.is-open .qtb-faq-question {
  color: var(--qtb-primary-strong);
}

.qtb-faq-item.is-open .qtb-faq-question::after {
  transform: rotate(45deg);
}

.qtb-faq-answer {
  padding: 0 22px 22px;
  color: var(--qtb-text-soft);
  line-height: 1.7;
  font-size: 0.96rem;
}

.qtb-faq-answer p { margin: 0; }

/* =============================================================================
 * 14 · Blog cards
 * ============================================================================= */

.qtb-blog-grid {
  display: grid;
  gap: 22px;
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.qtb-blog-archive {
  display: grid;
  gap: 22px;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  margin-bottom: 40px;
}

.qtb-blog-card {
  padding: 0;
  overflow: hidden;
  display: flex;
  flex-direction: column;
}

.qtb-blog-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--qtb-shadow);
  border-color: rgba(3, 105, 161, 0.30);
}

.qtb-blog-card__thumb {
  display: block;
  aspect-ratio: 16 / 9;
  background: var(--qtb-bg-alt);
  overflow: hidden;
}

.qtb-blog-card__thumb img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform var(--qtb-tx-md);
}

.qtb-blog-card:hover .qtb-blog-card__thumb img {
  transform: scale(1.04);
}

.qtb-blog-card__body {
  padding: 22px 22px 24px;
  display: flex;
  flex-direction: column;
  gap: 8px;
  flex: 1;
}

.qtb-blog-card__meta {
  margin: 0;
  font-size: 0.82rem;
  color: var(--qtb-text-faint);
}

.qtb-blog-card__title {
  margin: 0;
  font-size: 1.05rem;
  line-height: 1.45;
}

.qtb-blog-card__title a {
  color: var(--qtb-ink);
  transition: color var(--qtb-tx-xs);
}

.qtb-blog-card__title a:hover {
  color: var(--qtb-primary-strong);
}

.qtb-blog-card__excerpt {
  margin: 0;
  color: var(--qtb-text-soft);
  font-size: 0.92rem;
  line-height: 1.65;
  flex: 1;
}

.qtb-blog-card__link {
  margin-top: 8px;
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--qtb-primary);
  align-self: flex-start;
  transition: color var(--qtb-tx-xs);
}

.qtb-blog-card__link:hover { color: var(--qtb-cyan-strong); }

/* =============================================================================
 * 15 · Tag cloud
 * ============================================================================= */

.qtb-tag-cloud {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.qtb-tag-cloud a {
  display: inline-flex;
  background: var(--qtb-surface);
  border: 1px solid var(--qtb-border);
  color: var(--qtb-text);
  padding: 7px 14px;
  border-radius: var(--qtb-pill);
  font-size: 0.88rem;
  transition: background var(--qtb-tx-xs), color var(--qtb-tx-xs),
              border-color var(--qtb-tx-xs);
}

.qtb-tag-cloud a:hover {
  background: linear-gradient(135deg, var(--qtb-primary-soft), var(--qtb-cyan-soft));
  border-color: var(--qtb-primary);
  color: var(--qtb-primary-strong);
}

/* =============================================================================
 * 16 · CTA strip
 * ============================================================================= */

.qtb-cta-strip {
  background: var(--qtb-hero-grad);
  border-radius: var(--qtb-radius-xl);
  padding: 56px 48px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 28px;
  color: #fff;
  position: relative;
  overflow: hidden;
  box-shadow: var(--qtb-shadow-lg);
}

.qtb-cta-strip::after {
  content: "";
  position: absolute;
  width: 480px;
  height: 480px;
  right: -120px;
  top: -160px;
  border-radius: 50%;
  background: var(--qtb-tide-cyan);
  pointer-events: none;
}

.qtb-cta-strip > * { position: relative; z-index: 1; }

.qtb-cta-strip h2 {
  margin: 0 0 8px;
  font-size: clamp(1.5rem, 2.6vw, 2rem);
  letter-spacing: -0.01em;
}

.qtb-cta-strip p {
  margin: 0;
  color: rgba(255, 255, 255, 0.84);
}

.qtb-cta-strip__actions {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
}

/* =============================================================================
 * 17 · Footer
 * ============================================================================= */

.qtb-footer {
  margin-top: 80px;
  background:
    radial-gradient(circle at 92% 0%, rgba(45, 212, 255, 0.10), transparent 30%),
    linear-gradient(180deg, transparent, rgba(11, 107, 255, 0.05));
  border-top: 1px solid var(--qtb-border);
  padding: 60px 0 28px;
  color: var(--qtb-text-soft);
}

.qtb-footer__inner {
  display: grid;
  grid-template-columns: 1.5fr repeat(4, minmax(0, 1fr));
  gap: 36px;
  padding-bottom: 36px;
  border-bottom: 1px solid var(--qtb-border);
}

.qtb-footer__col--brand { min-width: 0; }

.qtb-footer__contact-list {
  list-style: none;
  padding: 0;
  margin: 16px 0 0;
  display: grid;
  gap: 6px;
  font-size: 0.88rem;
  line-height: 1.55;
}

.qtb-footer__contact-list li {
  display: grid;
  grid-template-columns: minmax(110px, 140px) 1fr;
  gap: 8px;
  align-items: baseline;
}

.qtb-footer__contact-label {
  color: var(--qtb-text-faint);
  letter-spacing: 0.02em;
  font-size: 0.78rem;
  text-transform: uppercase;
  font-weight: 600;
}

.qtb-footer__contact-list a {
  color: var(--qtb-primary-strong);
  word-break: break-word;
  border-bottom: 1px dashed transparent;
  transition: color var(--qtb-tx-xs), border-color var(--qtb-tx-xs);
}

.qtb-footer__contact-list a:hover {
  color: var(--qtb-cyan-strong);
  border-bottom-color: var(--qtb-cyan);
}

/* —— v10 信任徽章带（顶置 · ISO / SOC 2 / CSA STAR） —— */
.qtb-footer__trust {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 16px;
  padding: 0 0 26px;
  border-bottom: 1px dashed var(--qtb-border);
  margin-bottom: 26px;
}

.qtb-footer__trust-label {
  color: var(--qtb-text-faint);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  font-size: 0.74rem;
  font-weight: 700;
}

.qtb-footer__trust-list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 10px;
  list-style: none;
  margin: 0;
  padding: 0;
}

.qtb-footer__trust-item {
  display: inline-flex;
  align-items: center;
  padding: 6px 12px;
  border-radius: var(--qtb-pill);
  background: var(--qtb-cyan-soft);
  color: var(--qtb-cyan-strong);
  font-weight: 700;
  font-size: 0.78rem;
  letter-spacing: 0.02em;
  border: 1px solid rgba(45, 212, 255, 0.18);
}

/* —— 社交矩阵条 —— */
.qtb-footer__social {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  align-items: center;
  font-size: 0.92rem;
  padding: 22px 0 0;
}

.qtb-footer__social-label {
  color: var(--qtb-text-faint);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  font-size: 0.74rem;
  font-weight: 700;
}

.qtb-footer__social a {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 12px;
  border-radius: var(--qtb-pill);
  background: var(--qtb-primary-soft);
  color: var(--qtb-primary-strong);
  font-weight: 600;
  font-size: 0.84rem;
  border: 1px solid transparent;
  transition: background var(--qtb-tx-xs),
              border-color var(--qtb-tx-xs),
              transform var(--qtb-tx-xs);
}

.qtb-footer__social a:hover {
  background: #fff;
  border-color: var(--qtb-primary);
  transform: translateY(-1px);
}

.qtb-footer h4 {
  margin: 0 0 16px;
  font-size: 0.92rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--qtb-ink);
}

.qtb-footer ul {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  gap: 8px;
}

.qtb-footer ul a {
  color: var(--qtb-text-soft);
  font-size: 0.92rem;
  transition: color var(--qtb-tx-xs);
}

.qtb-footer ul a:hover { color: var(--qtb-primary-strong); }

.qtb-footer__brand-text {
  margin: 12px 0 0;
  font-size: 0.92rem;
  line-height: 1.7;
  max-width: 360px;
}

.qtb-footer__brand-text a { color: var(--qtb-primary-strong); }

.qtb-footer__bottom {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 12px;
  font-size: 0.86rem;
  color: var(--qtb-text-faint);
  padding-top: 24px;
}

.qtb-footer__friends {
  display: inline-flex;
  align-items: center;
  gap: 10px;
}

.qtb-footer__friends a {
  color: var(--qtb-primary);
  transition: color var(--qtb-tx-xs);
}

.qtb-footer__friends a:hover { color: var(--qtb-cyan-strong); }

/* =============================================================================
 * 18 · Page banner（用于 blog / help / privacy / terms / about / contact）
 * ============================================================================= */

.qtb-page-banner {
  position: relative;
  padding: 96px 0 60px;
  background:
    radial-gradient(ellipse 80% 60% at 80% 10%, rgba(20, 184, 166, 0.20), transparent 55%),
    radial-gradient(ellipse 60% 50% at 12% 90%, rgba(249, 115, 22, 0.15), transparent 55%),
    linear-gradient(180deg, rgba(3, 105, 161, 0.08), transparent 100%);
  border-bottom: 1px solid var(--qtb-border);
  text-align: center;
  overflow: hidden;
}

.qtb-page-banner h1 {
  margin: 8px auto 14px;
  font-size: clamp(1.7rem, 3.2vw, 2.4rem);
  color: var(--qtb-ink);
  max-width: 880px;
  letter-spacing: -0.01em;
  line-height: 1.25;
}

.qtb-page-banner p {
  margin: 0 auto;
  max-width: 720px;
  color: var(--qtb-text-soft);
  font-size: 1rem;
}

.qtb-page-body {
  padding: 60px 0 96px;
}

/* =============================================================================
 * 19 · Breadcrumb
 * ============================================================================= */

.qtb-breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-size: 0.86rem;
  color: var(--qtb-text-soft);
  margin-bottom: 28px;
}

.qtb-breadcrumb a {
  color: var(--qtb-text-soft);
  transition: color var(--qtb-tx-xs);
}

.qtb-breadcrumb a:hover { color: var(--qtb-primary-strong); }

.qtb-breadcrumb__sep { color: var(--qtb-text-faint); }

.qtb-breadcrumb [aria-current="page"] {
  color: var(--qtb-ink);
  font-weight: 600;
}

/* =============================================================================
 * 20 · Single post
 * ============================================================================= */

.qtb-single { padding: 48px 0 96px; }

.qtb-post-header { margin-bottom: 28px; }

.qtb-post-title {
  margin: 0 0 14px;
  font-size: clamp(1.7rem, 3.4vw, 2.6rem);
  color: var(--qtb-ink);
  letter-spacing: -0.01em;
  line-height: 1.2;
}

.qtb-post-meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-size: 0.88rem;
  color: var(--qtb-text-soft);
}

.qtb-post-meta a {
  color: var(--qtb-primary);
  transition: color var(--qtb-tx-xs);
}

.qtb-post-meta a:hover { color: var(--qtb-cyan-strong); }

.qtb-post-meta__sep { color: var(--qtb-text-faint); }

.qtb-read-time {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: var(--qtb-primary-soft);
  color: var(--qtb-primary-strong);
  padding: 4px 10px;
  border-radius: var(--qtb-pill);
  font-size: 0.78rem;
  font-weight: 600;
}

.qtb-read-time::before {
  content: "⌛";
  font-size: 0.86rem;
}

/* TL;DR 摘要框 */
.qtb-tldr {
  background: linear-gradient(135deg, var(--qtb-primary-soft), var(--qtb-cyan-soft));
  border-left: 4px solid var(--qtb-primary);
  border-radius: var(--qtb-radius-sm);
  padding: 16px 20px;
  margin: 0 0 28px;
  color: var(--qtb-ink-soft);
  line-height: 1.7;
  font-size: 0.96rem;
}

.qtb-tldr strong { color: var(--qtb-primary-strong); }

.qtb-post-thumbnail {
  margin: 0 0 28px;
  border-radius: var(--qtb-radius);
  overflow: hidden;
  box-shadow: var(--qtb-shadow-sm);
}

.qtb-post-featured-image {
  width: 100%;
  height: auto;
  display: block;
}

/* TOC 自动目录 */
.qtb-toc {
  background: var(--qtb-surface);
  border: 1px solid var(--qtb-border);
  border-left: 4px solid var(--qtb-primary);
  border-radius: var(--qtb-radius-sm);
  padding: 18px 22px;
  margin: 0 0 32px;
  font-size: 0.94rem;
}

.qtb-toc strong {
  display: block;
  margin-bottom: 10px;
  color: var(--qtb-ink);
  font-size: 0.95rem;
}

.qtb-toc ol {
  margin: 0;
  padding-left: 20px;
  display: grid;
  gap: 6px;
}

.qtb-toc a {
  color: var(--qtb-text-soft);
  transition: color var(--qtb-tx-xs);
}

.qtb-toc a:hover { color: var(--qtb-primary-strong); }

/* Prose */
.qtb-prose,
.qtb-post-content {
  color: var(--qtb-text);
  line-height: 1.8;
  font-size: 1rem;
  max-width: 760px;
  margin: 0 auto;
}

.qtb-prose h2,
.qtb-post-content h2 {
  margin: 40px 0 14px;
  color: var(--qtb-ink);
  font-size: 1.4rem;
  letter-spacing: -0.005em;
  scroll-margin-top: 90px;
}

.qtb-prose h3,
.qtb-post-content h3 {
  margin: 28px 0 10px;
  color: var(--qtb-ink);
  font-size: 1.16rem;
  scroll-margin-top: 90px;
}

.qtb-prose p,
.qtb-post-content p {
  margin: 0 0 16px;
}

.qtb-prose ul,
.qtb-prose ol,
.qtb-post-content ul,
.qtb-post-content ol {
  padding-left: 22px;
  margin: 0 0 18px;
}

.qtb-prose li,
.qtb-post-content li { margin: 6px 0; }

.qtb-prose code,
.qtb-post-content code {
  font-family: var(--qtb-font-mono);
  background: var(--qtb-bg-alt);
  border: 1px solid var(--qtb-border);
  border-radius: 6px;
  padding: 2px 6px;
  font-size: 0.9em;
  color: var(--qtb-cyan-strong);
}

.qtb-prose blockquote,
.qtb-post-content blockquote {
  margin: 22px 0;
  padding: 14px 22px;
  border-left: 4px solid var(--qtb-cyan);
  background: linear-gradient(90deg, var(--qtb-cyan-soft), transparent 80%);
  color: var(--qtb-text);
  font-style: italic;
  border-radius: 0 var(--qtb-radius-sm) var(--qtb-radius-sm) 0;
}

.qtb-prose__callout {
  background: linear-gradient(135deg, var(--qtb-primary-soft), var(--qtb-amber-soft));
  border: 1px solid rgba(3, 105, 161, 0.18);
  border-radius: var(--qtb-radius);
  padding: 18px 22px;
  margin: 0 0 30px;
  color: var(--qtb-ink-soft);
  font-size: 0.97rem;
  line-height: 1.7;
}

.qtb-bullets {
  list-style: none;
  padding: 0;
  display: grid;
  gap: 8px;
}

.qtb-bullets > li {
  position: relative;
  padding-left: 22px;
}

.qtb-bullets > li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 10px;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--qtb-primary), var(--qtb-cyan));
}

/* Author bio · E-E-A-T */
.qtb-author-bio {
  display: flex;
  gap: 18px;
  align-items: flex-start;
  background: var(--qtb-surface);
  border: 1px solid var(--qtb-border);
  border-radius: var(--qtb-radius);
  padding: 22px 24px;
  margin: 40px 0 0;
  box-shadow: var(--qtb-shadow-xs);
}

.qtb-author-bio__mark {
  width: 56px;
  height: 56px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--qtb-primary), var(--qtb-cyan));
  color: #fff;
  display: grid;
  place-items: center;
  font-weight: 800;
  font-size: 1.4rem;
  flex-shrink: 0;
  box-shadow: 0 8px 20px rgba(3, 105, 161, 0.34);
}

.qtb-author-bio__body { flex: 1; }

.qtb-author-bio__name {
  display: block;
  color: var(--qtb-ink);
  font-size: 1rem;
}

.qtb-author-bio__role {
  color: var(--qtb-primary-strong);
  font-size: 0.84rem;
  margin-left: 8px;
}

.qtb-author-bio__desc {
  margin: 8px 0 0;
  color: var(--qtb-text-soft);
  font-size: 0.94rem;
  line-height: 1.7;
}

/* Related posts */
.qtb-related {
  margin: 40px 0 0;
}

.qtb-related h2 {
  margin: 0 0 16px;
  color: var(--qtb-ink);
  font-size: 1.2rem;
}

.qtb-related__grid {
  display: grid;
  gap: 14px;
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.qtb-related__item {
  display: block;
  background: var(--qtb-surface);
  border: 1px solid var(--qtb-border);
  border-radius: var(--qtb-radius-sm);
  padding: 16px 18px;
  color: var(--qtb-ink);
  transition: border-color var(--qtb-tx-xs), box-shadow var(--qtb-tx-xs),
              transform var(--qtb-tx-xs);
  font-weight: 600;
  line-height: 1.5;
  font-size: 0.94rem;
}

.qtb-related__item small {
  display: block;
  color: var(--qtb-text-faint);
  font-size: 0.78rem;
  font-weight: 500;
  margin-bottom: 4px;
}

.qtb-related__item:hover {
  border-color: rgba(3, 105, 161, 0.32);
  box-shadow: var(--qtb-shadow-sm);
  transform: translateY(-2px);
}

/* Post navigation · prev / next */
.qtb-post-nav {
  display: grid;
  gap: 14px;
  grid-template-columns: 1fr 1fr;
  margin-top: 48px;
}

.qtb-post-nav__prev,
.qtb-post-nav__next {
  background: var(--qtb-surface);
  border: 1px solid var(--qtb-border);
  border-radius: var(--qtb-radius);
  padding: 16px 20px;
  color: var(--qtb-ink);
  transition: border-color var(--qtb-tx-xs), box-shadow var(--qtb-tx-xs);
}

.qtb-post-nav__next { text-align: right; }

.qtb-post-nav__prev:hover,
.qtb-post-nav__next:hover {
  border-color: rgba(3, 105, 161, 0.32);
  box-shadow: var(--qtb-shadow-sm);
}

.qtb-post-nav__label {
  display: block;
  font-size: 0.78rem;
  color: var(--qtb-primary);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin-bottom: 4px;
}

.qtb-post-nav__title {
  display: block;
  font-weight: 600;
  font-size: 0.95rem;
}

.qtb-post-pages {
  margin: 24px 0 0;
  font-size: 0.92rem;
  color: var(--qtb-text-soft);
}

.qtb-post-pages a {
  display: inline-block;
  background: var(--qtb-surface);
  border: 1px solid var(--qtb-border);
  padding: 4px 10px;
  border-radius: var(--qtb-radius-sm);
  margin: 0 4px;
  color: var(--qtb-text);
}

/* =============================================================================
 * 21 · Help center grid
 * ============================================================================= */

.qtb-help-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 22px;
  margin-bottom: 50px;
}

.qtb-help-card {
  padding: 24px 22px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.qtb-help-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--qtb-shadow);
  border-color: rgba(3, 105, 161, 0.30);
}

.qtb-help-card__icon {
  display: inline-grid;
  place-items: center;
  width: 42px;
  height: 42px;
  border-radius: 12px;
  background: linear-gradient(135deg, var(--qtb-primary-soft), var(--qtb-amber-soft));
  font-size: 1.2rem;
}

.qtb-help-card__links {
  list-style: none;
  padding: 0;
  margin: 6px 0 0;
  display: grid;
  gap: 6px;
}

.qtb-help-card__links a {
  color: var(--qtb-text-soft);
  font-size: 0.9rem;
  transition: color var(--qtb-tx-xs);
}

.qtb-help-card__links a:hover { color: var(--qtb-primary-strong); }

.qtb-help-section {
  background: var(--qtb-surface);
  border: 1px solid var(--qtb-border);
  border-radius: var(--qtb-radius);
  padding: 28px 32px;
  margin: 0 0 24px;
  box-shadow: var(--qtb-shadow-xs);
  scroll-margin-top: 90px;
}

.qtb-help-section h2 {
  margin: 0 0 14px;
  color: var(--qtb-ink);
  font-size: 1.3rem;
  letter-spacing: -0.005em;
}

.qtb-help-section h3 {
  margin: 24px 0 10px;
  color: var(--qtb-ink);
  font-size: 1.05rem;
  scroll-margin-top: 90px;
}

.qtb-help-section p {
  margin: 0 0 14px;
  color: var(--qtb-text);
  line-height: 1.75;
}

.qtb-help-section ul {
  margin: 0 0 16px;
  padding-left: 22px;
  color: var(--qtb-text);
}

.qtb-help-section li { margin: 6px 0; }

.qtb-help-section code {
  font-family: var(--qtb-font-mono);
  background: var(--qtb-bg-alt);
  border: 1px solid var(--qtb-border);
  border-radius: 6px;
  padding: 2px 6px;
  font-size: 0.9em;
  color: var(--qtb-cyan-strong);
}

/* —— Contact 表单 + 联系信息块 —— */
.qtb-contact-grid {
  display: grid;
  grid-template-columns: 1.1fr 1fr;
  gap: 32px;
  align-items: start;
}

.qtb-contact-card {
  background: var(--qtb-surface);
  border: 1px solid var(--qtb-border);
  border-radius: var(--qtb-radius);
  padding: 26px 28px;
  box-shadow: var(--qtb-shadow-xs);
}

.qtb-contact-card h3 {
  margin: 0 0 10px;
  color: var(--qtb-ink);
}

.qtb-contact-card p,
.qtb-contact-card a {
  color: var(--qtb-text);
}

.qtb-contact-card ul {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  gap: 8px;
}

.qtb-contact-card ul li::before {
  content: "›";
  color: var(--qtb-primary);
  margin-right: 8px;
  font-weight: 700;
}

/* =============================================================================
 * 22 · Pagination
 * ============================================================================= */

.qtb-pagination {
  display: flex;
  justify-content: center;
  margin: 36px 0;
}

.qtb-pagination ul {
  list-style: none;
  display: flex;
  gap: 8px;
  padding: 0;
  margin: 0;
  flex-wrap: wrap;
  justify-content: center;
}

.qtb-pagination a,
.qtb-pagination span {
  display: inline-grid;
  place-items: center;
  min-width: 38px;
  height: 38px;
  padding: 0 12px;
  border-radius: var(--qtb-radius-sm);
  border: 1px solid var(--qtb-border);
  background: var(--qtb-surface);
  color: var(--qtb-ink);
  font-weight: 600;
  font-size: 0.92rem;
  transition: background var(--qtb-tx-xs), color var(--qtb-tx-xs),
              border-color var(--qtb-tx-xs);
}

.qtb-pagination a:hover {
  background: var(--qtb-primary-soft);
  border-color: var(--qtb-primary);
  color: var(--qtb-primary-strong);
}

.qtb-pagination .current {
  background: linear-gradient(135deg, var(--qtb-primary), var(--qtb-cyan));
  color: #fff;
  border-color: transparent;
}

/* =============================================================================
 * 23 · Responsive
 * ============================================================================= */

@media (max-width: 1024px) {
  .qtb-card-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .qtb-plans { grid-template-columns: 1fr; }
  .qtb-download-grid { grid-template-columns: repeat(3, minmax(0, 1fr)); }
  .qtb-blog-grid,
  .qtb-blog-archive { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .qtb-help-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .qtb-related__grid { grid-template-columns: 1fr; }
  .qtb-footer__inner {
    grid-template-columns: 1.4fr 1fr 1fr;
    grid-auto-rows: minmax(0, auto);
  }
  .qtb-footer__col--brand { grid-column: 1 / -1; }
  .qtb-hero__grid { grid-template-columns: 1fr; }
  .qtb-hero__panel { padding: 56px 36px; }
  .qtb-stats-strip__grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .qtb-testimonial-card { flex: 0 0 calc((100% - 22px) / 2); }
  .qtb-contact-grid { grid-template-columns: 1fr; }
}

@media (max-width: 768px) {
  .qtb-section { padding: 64px 0; }
  .qtb-card-grid { grid-template-columns: 1fr; }
  .qtb-download-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .qtb-blog-grid,
  .qtb-blog-archive,
  .qtb-help-grid { grid-template-columns: 1fr; }
  .qtb-footer__inner { grid-template-columns: 1fr; }
  .qtb-footer__col--brand { grid-column: auto; }
  .qtb-footer__contact-list li { grid-template-columns: 1fr; gap: 2px; }
  .qtb-nav { display: none; }
  .qtb-menu-toggle { display: inline-flex; }
  .qtb-hero__panel { padding: 44px 24px; }
  .qtb-hero__title { font-size: clamp(1.7rem, 7vw, 2.2rem); }
  .qtb-cta-strip { padding: 38px 28px; flex-direction: column; align-items: flex-start; }
  .qtb-testimonial-card { flex: 0 0 100%; }
  .qtb-post-nav { grid-template-columns: 1fr; }
  .qtb-help-section { padding: 22px 20px; }
}

@media (max-width: 480px) {
  .qtb-stats-strip__grid { grid-template-columns: 1fr; }
  .qtb-billing-switch { width: 100%; }
  .qtb-billing-switch button { flex: 1; }
}

/* =============================================================================
 * 24 · Reveal-on-scroll
 * ============================================================================= */

[data-qtb-reveal] {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity 0.7s var(--qtb-ease-out), transform 0.7s var(--qtb-ease-out);
}

[data-qtb-reveal].is-shown {
  opacity: 1;
  transform: none;
}

@media (prefers-reduced-motion: reduce) {
  [data-qtb-reveal] { opacity: 1; transform: none; }
  *, *::before, *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
  }
}

/* =============================================================================
 * 25 · Print stylesheet
 * ============================================================================= */

@media print {
  .qtb-header,
  .qtb-footer,
  .qtb-mobile-overlay,
  .qtb-mobile-panel,
  .qtb-cta-strip,
  .qtb-related,
  .qtb-post-nav,
  .qtb-tag-cloud,
  .qtb-skip,
  [data-qtb-reveal] { display: none !important; opacity: 1 !important; }

  body { background: #fff !important; color: #000 !important; }
  .qtb-prose, .qtb-post-content { max-width: none !important; }
  a { color: inherit !important; text-decoration: underline !important; }
  a[href]::after { content: " (" attr(href) ")"; font-size: 0.85em; color: #555; }
}

/* =============================================================================
 * 26 · Legacy shims — 兼容旧 qb-* / qp-* 类名（保护既有插件 / 编辑器内容）
 * 仅为视觉兜底；新增内容应一律使用 qtb-* 命名空间。
 * ============================================================================= */

.qb-shell, .qp-shell           { min-height: 100vh; display: flex; flex-direction: column; overflow-x: clip; }
.qb-container, .qp-container   { width: min(92%, var(--qtb-container)); margin-inline: auto; }
.qb-main, .qp-main             { flex: 1; }
.qb-section, .qp-section       { padding: 96px 0; }
.qb-prose,  .qp-prose,
.qb-post-content,
.qp-post-content               { color: var(--qtb-text); line-height: 1.8; }
.qb-footer, .qp-footer         { margin-top: 80px; padding: 60px 0 28px; }

/* =============================================================================
 * 27 · Legacy 协议徽章 / 航线装饰
 * ---------------------------------------------------------------------------
 * 用法：
 *   <span class="qtb-wing-badge">WireGuard</span>
 *   <div class="qtb-trail-deco" aria-hidden="true"></div>
 * 设计意图：在文章 / 卡片中加入"双层航线光痕"装饰，呼应 Logo 的节点航线母题。
 * ============================================================================= */

.qtb-wing-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 4px 12px 4px 8px;
  border-radius: var(--qtb-pill);
  background: linear-gradient(95deg,
              var(--qtb-primary-soft) 0%,
              #ffffff 100%);
  color: var(--qtb-primary-strong);
  font-size: 0.74rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  border: 1px solid rgba(3, 105, 161, 0.22);
  line-height: 1;
}

.qtb-wing-badge::before {
  content: "";
  width: 14px;
  height: 14px;
  border-radius: 999px;
  background:
    radial-gradient(circle at 30% 30%, #fdba74 0%, transparent 60%),
    radial-gradient(circle at 70% 70%, #fdba74 0%, transparent 60%),
    var(--qtb-primary);
  box-shadow: 0 0 0 2px rgba(3, 105, 161, 0.20);
}

.qtb-trail-deco {
  position: relative;
  height: 1px;
  width: 100%;
  margin: 24px 0;
  background: linear-gradient(90deg,
              transparent 0%,
              var(--qtb-primary) 18%,
              var(--qtb-cyan) 50%,
              var(--qtb-amber) 82%,
              transparent 100%);
  opacity: 0.45;
}

.qtb-trail-deco::before,
.qtb-trail-deco::after {
  content: "";
  position: absolute;
  top: -3px;
  width: 7px;
  height: 7px;
  border-radius: 999px;
}

.qtb-trail-deco::before {
  left: 18%;
  background: var(--qtb-primary);
  box-shadow: 0 0 0 4px rgba(3, 105, 161, 0.18);
}

.qtb-trail-deco::after {
  right: 18%;
  background: var(--qtb-amber);
  box-shadow: 0 0 0 4px rgba(249, 115, 22, 0.20);
}