/* ============================================================
   纸飞机官网 · 站点主样式
   参考 telegram.org 的视觉语言：白底、蓝色点缀、克制圆角与留白
   设计系统 / 组件 / 页面 / 响应式
   ============================================================ */

/* ---------- 1. 设计变量 ---------- */
:root {
  --blue: #0088cc;
  --blue-600: #0088cc;
  --blue-700: #0077b3;
  --cyan: #179cde;
  --bar: #179cde;
  --soft: #e6f6fb;
  --soft-2: #f2fafd;
  --ink: #222222;
  --ink-2: #4d4d4d;
  --muted: #8c8c8c;
  --muted-2: #a6a6a6;
  --line: #e8e8e8;
  --line-2: #dcdcdc;
  --bg: #f7f7f7;
  --bg-2: #f0f5f8;
  --white: #fff;
  --green: #2e9e5b;
  --amber: #e6a23c;

  --radius-sm: 4px;
  --radius: 8px;
  --radius-lg: 10px;
  --radius-xl: 12px;

  --shadow-sm: 0 1px 3px rgba(0, 0, 0, .06);
  --shadow: 0 8px 24px -10px rgba(0, 0, 0, .16);
  --shadow-lg: 0 26px 60px -24px rgba(0, 0, 0, .28);

  --container: 960px;
  --header-h: 64px;

  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
}

/* ---------- 2. 基础重置 ---------- */
*,
*::before,
*::after { box-sizing: border-box; }

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

body {
  margin: 0;
  font-family: var(--font);
  font-size: 16px;
  line-height: 1.7;
  color: var(--ink);
  background: var(--white);
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

img { max-width: 100%; display: block; border: 0; }
a { color: var(--blue); text-decoration: none; }
button { font-family: inherit; }
ul, ol { margin: 0; padding: 0; }
h1, h2, h3, h4, h5 { margin: 0; font-weight: 600; letter-spacing: -.2px; line-height: 1.3; }
p { margin: 0; }

:focus-visible {
  outline: 2px solid var(--blue);
  outline-offset: 2px;
  border-radius: 4px;
}

::selection { background: rgba(0, 136, 204, .16); }

/* ---------- 3. 通用工具类 ---------- */
.container {
  width: 100%;
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 22px;
}

.section { padding: 76px 0; }
.section.tight { padding: 56px 0; }
.section.bg { background: var(--bg); }
.section.bg-2 { background: var(--bg-2); }

.section-head { max-width: 720px; margin: 0 auto 44px; text-align: center; }
.section-head.left { margin-left: 0; text-align: left; }

.eyebrow {
  display: inline-block;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 1.6px;
  text-transform: uppercase;
  color: var(--blue);
  margin-bottom: 12px;
}

.section-title {
  font-size: clamp(24px, 3vw, 32px);
  line-height: 1.3;
  color: var(--ink);
  letter-spacing: -.6px;
}
.section-sub {
  margin-top: 14px;
  font-size: 15.5px;
  line-height: 1.8;
  color: var(--muted);
}

.text-grad { color: var(--blue); }

.sr-only {
  position: absolute;
  width: 1px; height: 1px;
  padding: 0; margin: -1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
  border: 0;
}

/* ---------- 4. 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 22px;
  border-radius: var(--radius-sm);
  border: 1px solid transparent;
  font-size: 15px;
  font-weight: 600;
  line-height: 1.2;
  cursor: pointer;
  text-decoration: none;
  white-space: nowrap;
  transition: background .2s ease, color .2s ease, border-color .2s ease,
    box-shadow .2s ease, transform .2s ease;
}
.btn svg { width: 17px; height: 17px; flex: none; }

.btn-primary {
  color: #fff;
  background: var(--blue);
}
.btn-primary:hover {
  background: var(--blue-700);
  box-shadow: 0 6px 16px -6px rgba(0, 136, 204, .55);
}

.btn-dark {
  color: #fff;
  background: var(--ink);
}
.btn-dark:hover { background: #000; }

.btn-light {
  color: var(--blue);
  background: #fff;
  border-color: #fff;
}
.btn-light:hover { background: #f2fafd; }

.btn-ghost {
  color: var(--blue);
  background: transparent;
  border-color: var(--line-2);
}
.btn-ghost:hover {
  background: var(--soft-2);
  border-color: #b9dcf0;
}

.btn-outline {
  color: var(--blue);
  background: #fff;
  border-color: var(--line-2);
}
.btn-outline:hover {
  border-color: var(--blue);
  background: var(--soft-2);
}

.btn-sm { padding: 9px 16px; font-size: 13.5px; }
.btn-block { width: 100%; }

/* ---------- 5. 顶部公告条（隐藏，保持 telegram.org 简洁首屏） ---------- */
.topbar { display: none; }

/* ---------- 6. 页头导航 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 60;
  background: rgba(255, 255, 255, .92);
  -webkit-backdrop-filter: blur(16px);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--line);
  transition: box-shadow .25s ease;
}
.site-header.is-scrolled { box-shadow: 0 2px 10px rgba(0, 0, 0, .06); }
.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  height: var(--header-h);
}

.brand { display: flex; align-items: center; gap: 10px; color: var(--ink); }
.brand-mark {
  width: 38px; height: 38px;
  border-radius: 50%;
  display: grid;
  place-items: center;
  background: var(--blue);
  flex: none;
}
.brand-mark svg { width: 19px; height: 19px; }
.brand-text strong {
  display: block;
  font-size: 17px;
  line-height: 1.2;
  letter-spacing: 0;
  font-weight: 600;
}
.brand-text span {
  display: block;
  font-size: 9.5px;
  letter-spacing: 1.6px;
  color: var(--muted-2);
  text-transform: uppercase;
}

.main-nav ul { display: flex; align-items: center; gap: 2px; list-style: none; }
.main-nav a {
  position: relative;
  display: inline-block;
  padding: 20px 12px 17px;
  font-size: 15px;
  color: var(--blue);
  border-bottom: 3px solid transparent;
  transition: color .2s, border-color .2s;
}
.main-nav a:hover { color: var(--blue-700); border-bottom-color: rgba(23, 156, 222, .4); }
.main-nav a.active { color: var(--blue); font-weight: 600; border-bottom-color: var(--bar); }

.header-actions { display: flex; align-items: center; gap: 10px; }

.nav-toggle {
  display: none;
  width: 40px; height: 40px;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  background: #fff;
  cursor: pointer;
  padding: 0;
  place-items: center;
}
.nav-toggle span {
  display: block;
  width: 18px; height: 2px;
  background: var(--ink);
  border-radius: 2px;
  position: relative;
  transition: background .2s;
}
.nav-toggle span::before,
.nav-toggle span::after {
  content: "";
  position: absolute;
  left: 0;
  width: 18px; height: 2px;
  background: var(--ink);
  border-radius: 2px;
  transition: transform .25s;
}
.nav-toggle span::before { top: -6px; }
.nav-toggle span::after { top: 6px; }
.nav-toggle[aria-expanded="true"] span { background: transparent; }
.nav-toggle[aria-expanded="true"] span::before { transform: translateY(6px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] span::after { transform: translateY(-6px) rotate(-45deg); }

/* 移动端抽屉 */
.mobile-nav {
  position: fixed;
  inset: 0;
  z-index: 80;
  visibility: hidden;
  opacity: 0;
  transition: opacity .28s ease, visibility .28s ease;
}
.mobile-nav.is-open { visibility: visible; opacity: 1; }
.mobile-mask {
  position: absolute;
  inset: 0;
  background: rgba(0, 0, 0, .35);
}
.mobile-drawer {
  position: absolute;
  top: 0; right: 0;
  width: min(320px, 86%);
  height: 100%;
  background: #fff;
  padding: 18px 22px 30px;
  display: flex;
  flex-direction: column;
  gap: 4px;
  transform: translateX(100%);
  transition: transform .3s cubic-bezier(.22, .68, .36, 1);
  box-shadow: -20px 0 50px -30px rgba(0, 0, 0, .4);
  overflow-y: auto;
}
.mobile-nav.is-open .mobile-drawer { transform: none; }
.mobile-drawer .drawer-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-bottom: 14px;
  margin-bottom: 8px;
  border-bottom: 1px solid var(--line);
}
.drawer-close {
  width: 36px; height: 36px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--line);
  background: #fff;
  cursor: pointer;
  font-size: 20px;
  color: var(--muted);
  line-height: 1;
}
.mobile-drawer a {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 10px;
  border-radius: var(--radius-sm);
  color: var(--ink-2);
  font-size: 15px;
  font-weight: 500;
}
.mobile-drawer a:hover,
.mobile-drawer a.active { background: var(--soft-2); color: var(--blue); }
.mobile-drawer .drawer-cta { margin-top: 16px; display: grid; gap: 10px; }

/* ---------- 7. 首页 Hero ---------- */
.hero {
  position: relative;
  color: var(--ink);
  padding: 56px 0 68px;
  background: #fff;
  overflow: hidden;
}
.hero-inner {
  display: block;
}
.hero-copy {
  max-width: 800px;
  margin: 0 auto;
  text-align: center;
}
.hero-mark {
  width: 92px; height: 92px;
  margin: 0 auto 20px;
  border-radius: 50%;
  display: grid;
  place-items: center;
  background: var(--blue);
  box-shadow: 0 18px 40px -18px rgba(0, 136, 204, .7);
}
.hero-mark svg { width: 44px; height: 44px; }

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 5px 13px;
  margin-bottom: 18px;
  border-radius: 999px;
  font-size: 12.5px;
  color: var(--blue);
  background: var(--soft);
  border: 1px solid #d3edf7;
}
.hero-badge i {
  width: 6px; height: 6px;
  border-radius: 50%;
  background: var(--blue);
}

.hero h1 {
  font-size: clamp(30px, 4.4vw, 48px);
  line-height: 1.18;
  font-weight: 600;
  letter-spacing: -1px;
  margin-bottom: 18px;
  color: var(--ink);
}
.hero-sub {
  max-width: 640px;
  margin: 0 auto 28px;
  font-size: 17px;
  line-height: 1.8;
  color: var(--muted);
}
.hero-sub strong { color: var(--ink-2); font-weight: 600; }
.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  justify-content: center;
  margin-bottom: 22px;
}
.hero-notes {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 8px 22px;
  font-size: 13px;
  color: var(--muted);
}
.hero-notes span { display: inline-flex; align-items: center; gap: 6px; }
.hero-notes svg { width: 15px; height: 15px; color: var(--blue); }

.hero-visual {
  position: relative;
  display: flex;
  justify-content: center;
  margin-top: 44px;
}
.hero-orb { display: none; }
.hero-shot {
  position: relative;
  width: 100%;
  max-width: 840px;
  border-radius: 12px;
  overflow: hidden;
  border: 1px solid var(--line);
  box-shadow: 0 34px 70px -38px rgba(0, 0, 0, .32);
  background: var(--bg);
}
.hero-shot img {
  display: block;
  width: 100%;
  height: auto;
}
.float-card { display: none; }

.hero-stats {
  position: relative;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 18px;
  margin-top: 56px;
  padding-top: 28px;
  border-top: 1px solid var(--line);
  text-align: center;
}
.hero-stats .hs-item b {
  display: block;
  font-size: clamp(22px, 2.4vw, 30px);
  font-weight: 600;
  line-height: 1.2;
  letter-spacing: -.5px;
  color: var(--ink);
}
.hero-stats .hs-item b em { font-style: normal; color: var(--blue); }
.hero-stats .hs-item span { font-size: 12.5px; color: var(--muted); }

/* ---------- 8. 系统支持条 ---------- */
.os-strip {
  background: var(--bg);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  padding: 18px 0;
}
.os-strip .container {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 26px;
  flex-wrap: wrap;
}
.os-strip .os-label {
  font-size: 12.5px;
  font-weight: 600;
  letter-spacing: .5px;
  color: var(--muted);
  white-space: nowrap;
}
.os-list { display: flex; flex-wrap: wrap; gap: 8px 24px; align-items: center; }
.os-item {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  font-size: 13px;
  color: var(--ink-2);
}
.os-item svg { width: 16px; height: 16px; color: var(--blue); }

/* ---------- 9. 平台下载卡片 ---------- */
.platform-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
}
.platform-card {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 12px;
  padding: 22px 22px 18px;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  color: var(--ink);
  transition: border-color .2s ease, box-shadow .2s ease;
}
.platform-card:hover {
  border-color: #b9dcf0;
  box-shadow: var(--shadow-sm);
}
.platform-card .pc-top { display: flex; align-items: center; gap: 12px; }
.platform-card .pc-icon {
  width: 42px; height: 42px;
  border-radius: var(--radius-sm);
  display: grid;
  place-items: center;
  background: var(--soft);
  color: var(--blue);
  flex: none;
  transition: background .2s, color .2s;
}
.platform-card .pc-icon svg { width: 21px; height: 21px; }
.platform-card:hover .pc-icon { background: var(--blue); color: #fff; }
.platform-card h3 { font-size: 16.5px; }
.platform-card .pc-sub { font-size: 12.5px; color: var(--muted); margin-top: 1px; }
.platform-card p.pc-desc {
  font-size: 14px;
  line-height: 1.7;
  color: var(--muted);
  margin: 0;
}
.platform-card .pc-foot {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-top: auto;
  padding-top: 12px;
  border-top: 1px solid var(--line);
  font-size: 12.5px;
  color: var(--muted-2);
}
.platform-card .pc-foot .arrow {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  color: var(--blue);
  font-weight: 600;
}
.platform-card .pc-foot .arrow svg { width: 14px; height: 14px; transition: transform .2s; }
.platform-card:hover .pc-foot .arrow svg { transform: translateX(3px); }

/* ---------- 10. 功能卡片网格 ---------- */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}
.feature-card {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  transition: border-color .2s ease, box-shadow .2s ease;
}
.feature-card:hover { border-color: #b9dcf0; box-shadow: var(--shadow-sm); }
.feature-thumb {
  position: relative;
  overflow: hidden;
  background: var(--soft-2);
  border-bottom: 1px solid var(--line);
}
.feature-thumb img {
  display: block;
  width: 100%; height: auto;
  transition: transform .5s ease;
}
.feature-card:hover .feature-thumb img { transform: scale(1.04); }
.feature-body { padding: 22px 24px 26px; }
.feature-body h3 { font-size: 18px; margin-bottom: 8px; }
.feature-body p { font-size: 14.5px; line-height: 1.75; color: var(--muted); }
.feature-body .f-tag {
  display: inline-block;
  margin-bottom: 10px;
  padding: 2px 9px;
  border-radius: var(--radius-sm);
  background: var(--soft);
  color: var(--blue);
  font-size: 11.5px;
  font-weight: 600;
  letter-spacing: .4px;
}

/* ---------- 11. 图文分栏 ---------- */
.split {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 52px;
  align-items: center;
}
.split.reverse .split-media { order: 2; }
.split-media { position: relative; }
.split-media .media-frame {
  position: relative;
  border-radius: var(--radius-lg);
  overflow: hidden;
  aspect-ratio: 840 / 487;
  background: var(--soft-2);
  border: 1px solid var(--line);
  box-shadow: var(--shadow-sm);
}
.split-media .media-frame img {
  display: block;
  width: 100%; height: auto;
}
.split-media .media-badge {
  position: absolute;
  left: 16px; bottom: 16px;
  z-index: 2;
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 13px;
  border-radius: var(--radius-sm);
  background: rgba(255, 255, 255, .95);
  border: 1px solid rgba(255, 255, 255, .9);
  box-shadow: 0 4px 14px rgba(0, 0, 0, .12);
  font-size: 12.5px;
  color: var(--ink-2);
  font-weight: 600;
}
.split-media .media-badge svg { width: 15px; height: 15px; color: var(--blue); }
.split-media .deco-ring { display: none; }
.split-content .section-title { margin-bottom: 14px; }
.split-content > p {
  font-size: 15px;
  line-height: 1.8;
  color: var(--muted);
  margin-bottom: 22px;
}
.check-list { display: grid; gap: 12px; margin: 0 0 26px; list-style: none; }
.check-list li {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  font-size: 14.5px;
  color: var(--ink-2);
  line-height: 1.7;
}
.check-list .tick {
  flex: none;
  width: 20px; height: 20px;
  margin-top: 3px;
  border-radius: 50%;
  display: grid;
  place-items: center;
  background: var(--soft);
  color: var(--blue);
}
.check-list .tick svg { width: 12px; height: 12px; }
.check-list b { color: var(--ink); font-weight: 600; }

/* ---------- 12. 下载步骤 ---------- */
.steps { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.step-card {
  position: relative;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 30px 26px 26px;
  overflow: hidden;
}
.step-card .step-num {
  position: absolute;
  right: 16px; top: 4px;
  font-size: 56px;
  font-weight: 700;
  line-height: 1;
  color: #f2f2f2;
  letter-spacing: -2px;
}
.step-card .step-icon {
  position: relative;
  z-index: 1;
  width: 46px; height: 46px;
  display: grid;
  place-items: center;
  border-radius: var(--radius-sm);
  background: var(--soft);
  color: var(--blue);
  margin-bottom: 16px;
}
.step-card .step-icon svg { width: 22px; height: 22px; }
.step-card h3 { position: relative; z-index: 1; font-size: 17px; margin-bottom: 6px; }
.step-card p { position: relative; z-index: 1; font-size: 14px; line-height: 1.75; color: var(--muted); }

/* ---------- 13. 对比表格 ---------- */
.table-wrap {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
}
.table-scroll { overflow-x: auto; }
table.data-table {
  width: 100%;
  border-collapse: collapse;
  min-width: 640px;
  font-size: 14px;
}
table.data-table thead th {
  padding: 14px 22px;
  text-align: left;
  font-size: 13px;
  font-weight: 600;
  color: var(--ink-2);
  background: var(--bg);
  border-bottom: 1px solid var(--line);
  white-space: nowrap;
}
table.data-table tbody td {
  padding: 14px 22px;
  border-top: 1px solid var(--line);
  color: var(--ink-2);
  vertical-align: middle;
}
table.data-table tbody td:first-child { font-weight: 600; color: var(--ink); }
table.data-table tbody tr:nth-child(even) { background: #fafafa; }
table.data-table .ok {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  color: var(--green);
  font-weight: 600;
}
table.data-table .ok svg { width: 15px; height: 15px; }
table.data-table .no { color: var(--muted-2); }

/* ---------- 14. FAQ 折叠面板 ---------- */
.accordion { display: grid; gap: 10px; }
.acc-item {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  overflow: hidden;
  transition: border-color .2s, background .2s;
}
.acc-item.open { border-color: #b9dcf0; background: #fff; }
.acc-btn {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  padding: 17px 20px;
  background: transparent;
  border: 0;
  cursor: pointer;
  text-align: left;
  font-size: 15px;
  font-weight: 600;
  color: var(--ink);
  line-height: 1.55;
}
.acc-btn .q { display: flex; align-items: flex-start; gap: 10px; }
.acc-btn .q i {
  flex: none;
  font-style: normal;
  font-size: 11.5px;
  font-weight: 700;
  color: var(--blue);
  background: var(--soft);
  border-radius: 3px;
  padding: 2px 6px;
  margin-top: 3px;
}
.acc-icon {
  flex: none;
  width: 28px; height: 28px;
  border-radius: 50%;
  border: 1px solid var(--line-2);
  display: grid;
  place-items: center;
  color: var(--blue);
  transition: transform .25s, background .25s, color .25s, border-color .25s;
}
.acc-icon svg { width: 12px; height: 12px; }
.acc-item.open .acc-icon {
  transform: rotate(135deg);
  background: var(--blue);
  border-color: var(--blue);
  color: #fff;
}
.acc-panel { max-height: 0; overflow: hidden; transition: max-height .32s ease; }
.acc-body {
  padding: 0 20px 20px 48px;
  font-size: 14.5px;
  line-height: 1.85;
  color: var(--muted);
}
.acc-body p + p { margin-top: 10px; }
.acc-body a { color: var(--blue); font-weight: 500; }

/* ---------- 15. 博客卡片 ---------- */
.blog-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.post-card {
  display: flex;
  flex-direction: column;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  color: var(--ink);
  transition: border-color .2s, box-shadow .2s;
}
.post-card:hover { border-color: #b9dcf0; box-shadow: var(--shadow-sm); }
.post-thumb { overflow: hidden; background: var(--soft-2); border-bottom: 1px solid var(--line); }
.post-thumb img {
  display: block;
  width: 100%; height: auto;
  transition: transform .45s ease;
}
.post-card:hover .post-thumb img { transform: scale(1.04); }
.post-body { padding: 20px 22px 24px; display: flex; flex-direction: column; flex: 1; }
.post-meta {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
  font-size: 12px;
  color: var(--muted-2);
  margin-bottom: 10px;
}
.post-meta .tag {
  padding: 2px 8px;
  border-radius: 3px;
  background: var(--soft);
  color: var(--blue);
  font-weight: 600;
  font-size: 11.5px;
}
.post-meta .dot { width: 3px; height: 3px; border-radius: 50%; background: #d0d0d0; }
.post-card h3 {
  font-size: 17px;
  line-height: 1.5;
  margin-bottom: 8px;
  transition: color .2s;
}
.post-card:hover h3 { color: var(--blue); }
.post-card p {
  font-size: 14px;
  line-height: 1.7;
  color: var(--muted);
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}
.post-more {
  margin-top: 16px;
  display: inline-flex;
  align-items: center;
  gap: 5px;
  font-size: 13px;
  font-weight: 600;
  color: var(--blue);
}
.post-more svg { width: 14px; height: 14px; transition: transform .2s; }
.post-card:hover .post-more svg { transform: translateX(3px); }

/* ---------- 16. CTA 区块 ---------- */
.cta-band {
  padding: 48px 44px;
  border-radius: var(--radius-lg);
  text-align: center;
  color: var(--ink);
  background: var(--soft);
  border: 1px solid #d3edf7;
}
.cta-band h2 {
  font-size: clamp(24px, 2.8vw, 30px);
  line-height: 1.3;
  margin-bottom: 12px;
}
.cta-band p {
  max-width: 620px;
  margin: 0 auto 26px;
  font-size: 15px;
  line-height: 1.8;
  color: var(--ink-2);
}
.cta-actions { display: flex; flex-wrap: wrap; gap: 12px; justify-content: center; }
.cta-mini { margin-top: 18px; font-size: 12.5px; color: var(--muted); }

/* ---------- 17. 页脚 ---------- */
.site-footer {
  margin-top: 76px;
  background: var(--bg);
  color: var(--muted);
  border-top: 1px solid var(--line);
  padding-top: 52px;
}
.footer-grid {
  display: grid;
  grid-template-columns: 1.6fr 1fr 1fr 1fr;
  gap: 36px;
  padding-bottom: 40px;
  border-bottom: 1px solid var(--line);
}
.footer-brand .brand { color: var(--ink); }
.footer-brand .brand-text span { color: var(--muted-2); }
.footer-brand p {
  margin: 16px 0 18px;
  font-size: 13.5px;
  line-height: 1.8;
  color: var(--muted);
  max-width: 300px;
}
.footer-os { display: flex; flex-wrap: wrap; gap: 6px; }
.footer-os span {
  padding: 4px 10px;
  border-radius: 3px;
  border: 1px solid var(--line);
  background: #fff;
  font-size: 11.5px;
  color: var(--muted);
}
.footer-col h4 {
  font-size: 13.5px;
  color: var(--ink);
  letter-spacing: .3px;
  margin-bottom: 14px;
}
.footer-col ul { list-style: none; display: grid; gap: 9px; }
.footer-col a { font-size: 13px; color: var(--muted); transition: color .2s; }
.footer-col a:hover { color: var(--blue); }
.footer-bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
  padding: 20px 0;
  font-size: 12.5px;
  color: var(--muted-2);
}
.footer-bottom .fb-links { display: flex; flex-wrap: wrap; gap: 16px; }
.footer-bottom a { color: var(--muted); }
.footer-bottom a:hover { color: var(--blue); }
.footer-keywords {
  padding: 0 0 22px;
  font-size: 11.5px;
  line-height: 1.9;
  color: #b3b3b3;
  letter-spacing: .2px;
}
.footer-keywords b { color: #9e9e9e; font-weight: 500; }

/* ---------- 18. 子页面横幅 ---------- */
.page-hero {
  position: relative;
  padding: 40px 0 48px;
  color: var(--ink);
  background: var(--bg);
  border-bottom: 1px solid var(--line);
}
.page-hero .container { position: relative; z-index: 2; }
.breadcrumb {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 7px;
  font-size: 12.5px;
  color: var(--muted);
  margin-bottom: 16px;
}
.breadcrumb a { color: var(--muted); }
.breadcrumb a:hover { color: var(--blue); }
.breadcrumb .sep { color: var(--line-2); }
.page-hero h1 {
  font-size: clamp(26px, 3.4vw, 36px);
  line-height: 1.25;
  letter-spacing: -.6px;
  margin-bottom: 12px;
  color: var(--ink);
}
.page-hero .ph-sub {
  max-width: 720px;
  font-size: 15.5px;
  line-height: 1.8;
  color: var(--ink-2);
}
.page-hero .ph-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 22px;
}
.page-hero .ph-meta span {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 5px 12px;
  border-radius: 999px;
  background: #fff;
  border: 1px solid var(--line);
  font-size: 12px;
  color: var(--ink-2);
}
.page-hero .ph-meta svg { width: 13px; height: 13px; color: var(--blue); }

/* ---------- 19. 下载页 ---------- */
.dl-toolbar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 26px;
}
.tabs {
  display: inline-flex;
  flex-wrap: wrap;
  gap: 4px;
  padding: 4px;
  background: #f0f0f0;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
}
.tab-btn {
  padding: 8px 18px;
  border: 0;
  border-radius: 3px;
  background: transparent;
  font-size: 13.5px;
  color: var(--ink-2);
  cursor: pointer;
  transition: background .2s, color .2s, box-shadow .2s;
}
.tab-btn.active {
  background: #fff;
  color: var(--blue);
  font-weight: 600;
  box-shadow: var(--shadow-sm);
}
.dl-tip { font-size: 12.5px; color: var(--muted); display: inline-flex; align-items: center; gap: 6px; }
.dl-tip svg { width: 14px; height: 14px; color: var(--blue); }

.tab-panel { display: none; }
.tab-panel.active { display: block; animation: fadeUp .35s ease both; }

.dl-card {
  display: grid;
  grid-template-columns: 1.06fr .94fr;
  gap: 40px;
  align-items: center;
  padding: 36px;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
}
.dl-card .dl-chip {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 3px 10px;
  border-radius: var(--radius-sm);
  background: #eaf7ef;
  color: var(--green);
  font-size: 11.5px;
  font-weight: 600;
  margin-bottom: 12px;
}
.dl-card h2 { font-size: clamp(22px, 2.5vw, 28px); margin-bottom: 10px; letter-spacing: -.5px; }
.dl-card p.dl-intro { font-size: 14.5px; line-height: 1.8; color: var(--muted); margin-bottom: 20px; }
.dl-meta { display: grid; grid-template-columns: repeat(3, 1fr); gap: 10px; margin-bottom: 22px; }
.dl-meta div {
  background: var(--bg);
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  padding: 10px 12px;
}
.dl-meta small { display: block; font-size: 11px; color: var(--muted-2); letter-spacing: .4px; margin-bottom: 2px; }
.dl-meta b { font-size: 13px; color: var(--ink); font-weight: 600; }
.dl-actions { display: flex; flex-wrap: wrap; gap: 10px; align-items: center; }
.dl-hash {
  margin-top: 16px;
  padding: 9px 12px;
  border-radius: var(--radius-sm);
  background: var(--bg);
  border: 1px solid var(--line);
  color: #6f6f6f;
  font-family: ui-monospace, SFMono-Regular, Consolas, monospace;
  font-size: 11.5px;
  letter-spacing: .3px;
  overflow-wrap: anywhere;
}
.dl-shot {
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--line);
  background: var(--soft-2);
  box-shadow: var(--shadow-sm);
}
.dl-shot img { display: block; width: 100%; height: auto; }

.req-title { font-size: 17px; margin-bottom: 16px; }
.install-steps { display: grid; gap: 14px; counter-reset: ist; }
.install-step {
  position: relative;
  padding: 20px 24px 20px 62px;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
}
.install-step::before {
  counter-increment: ist;
  content: counter(ist);
  position: absolute;
  left: 20px; top: 20px;
  width: 28px; height: 28px;
  border-radius: 50%;
  display: grid;
  place-items: center;
  background: var(--soft);
  color: var(--blue);
  font-size: 12.5px;
  font-weight: 700;
}
.install-step h4 { font-size: 15px; margin-bottom: 5px; }
.install-step p { font-size: 13.5px; line-height: 1.75; color: var(--muted); }

.side-note {
  padding: 22px 24px;
  border-radius: var(--radius);
  background: var(--soft);
  border: 1px solid #d3edf7;
}
.side-note h4 { font-size: 15px; margin-bottom: 6px; color: var(--ink); }
.side-note p { font-size: 13px; line-height: 1.75; color: var(--ink-2); }
.side-note a { font-weight: 600; }

/* ---------- 20. FAQ 页 ---------- */
.faq-tools {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  padding: 14px 16px;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  margin-bottom: 24px;
}
.faq-search { position: relative; flex: 1 1 280px; }
.faq-search svg {
  position: absolute;
  left: 14px; top: 50%;
  transform: translateY(-50%);
  width: 16px; height: 16px;
  color: var(--muted-2);
  pointer-events: none;
}
.faq-search input {
  width: 100%;
  height: 42px;
  padding: 0 14px 0 40px;
  border: 1px solid var(--line-2);
  border-radius: var(--radius-sm);
  background: #fff;
  font-size: 14px;
  color: var(--ink);
  outline: none;
  transition: border-color .2s, box-shadow .2s;
}
.faq-search input:focus {
  border-color: var(--blue);
  box-shadow: 0 0 0 3px rgba(0, 136, 204, .12);
}
.chips { display: flex; flex-wrap: wrap; gap: 6px; }
.chip {
  padding: 7px 14px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--line-2);
  background: #fff;
  color: var(--ink-2);
  font-size: 13px;
  cursor: pointer;
  transition: background .2s, border-color .2s, color .2s;
}
.chip:hover { border-color: #b9dcf0; color: var(--blue); }
.chip.active { background: var(--blue); border-color: var(--blue); color: #fff; }
.faq-empty {
  display: none;
  padding: 36px 20px;
  text-align: center;
  color: var(--muted);
  font-size: 14px;
  background: #fff;
  border: 1px dashed var(--line-2);
  border-radius: var(--radius);
}
.faq-empty.show { display: block; }
.faq-count { font-size: 12.5px; color: var(--muted-2); margin-bottom: 14px; }

/* ---------- 21. 关于我们 ---------- */
.about-stats { display: grid; grid-template-columns: repeat(4, 1fr); gap: 18px; }
.about-stat {
  padding: 24px 20px;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  text-align: center;
}
.about-stat b {
  display: block;
  font-size: 28px;
  font-weight: 600;
  color: var(--blue);
  letter-spacing: -.5px;
}
.about-stat span { font-size: 12.5px; color: var(--muted); }

.value-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.value-card {
  padding: 26px 24px;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
}
.value-card .v-icon {
  width: 44px; height: 44px;
  border-radius: var(--radius-sm);
  display: grid;
  place-items: center;
  background: var(--soft);
  color: var(--blue);
  margin-bottom: 16px;
}
.value-card .v-icon svg { width: 21px; height: 21px; }
.value-card h3 { font-size: 17px; margin-bottom: 6px; }
.value-card p { font-size: 14px; line-height: 1.75; color: var(--muted); }

.timeline { position: relative; padding-left: 28px; }
.timeline::before {
  content: "";
  position: absolute;
  left: 5px; top: 6px; bottom: 6px;
  width: 2px;
  background: #d5eaf5;
}
.timeline-item { position: relative; padding-bottom: 30px; }
.timeline-item:last-child { padding-bottom: 0; }
.timeline-item::before {
  content: "";
  position: absolute;
  left: -27px; top: 5px;
  width: 10px; height: 10px;
  border-radius: 50%;
  background: #fff;
  border: 2px solid var(--blue);
}
.timeline-item time {
  display: inline-block;
  font-size: 11.5px;
  font-weight: 600;
  letter-spacing: .8px;
  color: var(--blue);
  margin-bottom: 4px;
}
.timeline-item h4 { font-size: 15.5px; margin-bottom: 5px; }
.timeline-item p { font-size: 13.5px; line-height: 1.75; color: var(--muted); }

.contact-card {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
}
.contact-item {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  padding: 20px 22px;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
}
.contact-item .c-icon {
  flex: none;
  width: 38px; height: 38px;
  border-radius: var(--radius-sm);
  display: grid;
  place-items: center;
  background: var(--soft);
  color: var(--blue);
}
.contact-item .c-icon svg { width: 18px; height: 18px; }
.contact-item h4 { font-size: 14px; margin-bottom: 2px; }
.contact-item p { font-size: 13px; color: var(--muted); line-height: 1.65; }

/* ---------- 22. 博客页 ---------- */
.blog-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 300px;
  gap: 36px;
  align-items: start;
}
.featured-post {
  display: grid;
  grid-template-columns: 1.02fr .98fr;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  margin-bottom: 32px;
  transition: border-color .2s, box-shadow .2s;
}
.featured-post:hover { box-shadow: var(--shadow-sm); border-color: #b9dcf0; }
.featured-post .fp-thumb { position: relative; background: var(--soft-2); }
.featured-post .fp-thumb img { display: block; width: 100%; height: auto; }
.featured-post .fp-body { padding: 32px 30px; display: flex; flex-direction: column; justify-content: center; }
.featured-post .fp-body .post-meta { margin-bottom: 12px; }
.featured-post h2 { font-size: clamp(20px, 2.1vw, 25px); line-height: 1.4; margin-bottom: 10px; }
.featured-post p { font-size: 14px; line-height: 1.75; color: var(--muted); margin-bottom: 18px; }

.sidebar { display: grid; gap: 18px; position: sticky; top: 88px; }
.side-card {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 20px;
}
.side-card h3 {
  font-size: 14.5px;
  margin-bottom: 14px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--line);
}
.side-card .popular-list { display: grid; gap: 12px; list-style: none; }
.side-card .popular-list a { display: flex; gap: 10px; align-items: flex-start; color: var(--ink); }
.side-card .popular-list .rank {
  flex: none;
  width: 22px; height: 22px;
  border-radius: 3px;
  display: grid;
  place-items: center;
  background: var(--soft);
  color: var(--blue);
  font-size: 11.5px;
  font-weight: 700;
}
.side-card .popular-list a:hover .p-title { color: var(--blue); }
.side-card .popular-list .p-title { font-size: 13.5px; line-height: 1.55; }
.side-card .popular-list .p-date { font-size: 11.5px; color: var(--muted-2); margin-top: 2px; display: block; }
.tag-cloud { display: flex; flex-wrap: wrap; gap: 6px; }
.tag-cloud a {
  padding: 5px 11px;
  border-radius: 3px;
  background: var(--bg);
  border: 1px solid var(--line);
  font-size: 12px;
  color: var(--ink-2);
}
.tag-cloud a:hover { background: var(--blue); border-color: var(--blue); color: #fff; }
.newsletter {
  background: var(--soft);
  border-color: #d3edf7;
}
.newsletter h3 { border-bottom-color: #cfe9f3; color: var(--ink); }
.newsletter p { font-size: 12.5px; line-height: 1.75; color: var(--ink-2); margin-bottom: 12px; }
.newsletter form { display: grid; gap: 8px; }
.newsletter input {
  height: 40px;
  padding: 0 12px;
  border-radius: var(--radius-sm);
  border: 1px solid #cfe3ec;
  background: #fff;
  color: var(--ink);
  font-size: 13px;
  outline: none;
}
.newsletter input::placeholder { color: var(--muted-2); }
.newsletter input:focus { border-color: var(--blue); }

.pagination { display: flex; justify-content: center; gap: 6px; margin-top: 36px; }
.page-num {
  width: 36px; height: 36px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--line);
  background: #fff;
  display: grid;
  place-items: center;
  font-size: 13.5px;
  color: var(--ink-2);
}
.page-num:hover { border-color: var(--blue); color: var(--blue); }
.page-num.active { background: var(--blue); border-color: var(--blue); color: #fff; font-weight: 600; }

/* ---------- 23. 回到顶部 ---------- */
.back-top {
  position: fixed;
  right: 22px; bottom: 24px;
  z-index: 70;
  width: 42px; height: 42px;
  border-radius: 50%;
  border: 1px solid var(--line);
  background: #fff;
  color: var(--blue);
  display: grid;
  place-items: center;
  cursor: pointer;
  box-shadow: 0 6px 18px rgba(0, 0, 0, .12);
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  transition: opacity .25s, visibility .25s, transform .25s;
}
.back-top.show { opacity: 1; visibility: visible; transform: none; }
.back-top svg { width: 17px; height: 17px; }

/* ---------- 24. 滚动浮现动画 ---------- */
[data-reveal] {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity .55s ease, transform .55s ease;
  will-change: opacity, transform;
}
[data-reveal].is-visible { opacity: 1; transform: none; }

@keyframes fadeUp {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: none; }
}

/* ---------- 滚动定位留出吸顶导航高度 ---------- */
.section,
#windows, #mac, #linux, #android, #ios, #web,
#install, #requirements, #downloads,
#story, #disclaimer, #privacy, #terms, #security { scroll-margin-top: 84px; }

/* ---------- 25. 响应式 ---------- */
@media (max-width: 1080px) {
  .feature-grid,
  .platform-grid,
  .blog-grid,
  .steps,
  .value-grid { gap: 16px; }
  .blog-layout { grid-template-columns: minmax(0, 1fr) 280px; gap: 28px; }
  .split { gap: 40px; }
  .dl-card { gap: 28px; padding: 30px; }
}

@media (max-width: 940px) {
  .main-nav { display: none; }
  .nav-toggle { display: grid; }
  .header-actions .btn { display: none; }
  .hero { padding: 44px 0 56px; }
  .hero-shot { max-width: 380px; }
  .hero-stats { grid-template-columns: repeat(2, 1fr); gap: 22px 16px; margin-top: 44px; }
  .platform-grid,
  .feature-grid,
  .steps,
  .blog-grid,
  .value-grid { grid-template-columns: repeat(2, 1fr); }
  .split,
  .split.reverse { grid-template-columns: 1fr; gap: 32px; }
  .split.reverse .split-media { order: 0; }
  .blog-layout { grid-template-columns: 1fr; }
  .sidebar { position: static; grid-template-columns: 1fr 1fr; }
  .featured-post { grid-template-columns: 1fr; }
  .dl-card { grid-template-columns: 1fr; }
  .dl-shot { order: -1; }
  .about-stats { grid-template-columns: repeat(2, 1fr); }
  .contact-card { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr 1fr; gap: 30px; }
}

@media (max-width: 640px) {
  .section { padding: 56px 0; }
  .section-head { margin-bottom: 30px; }
  .header-inner { height: 60px; }
  .brand-mark { width: 34px; height: 34px; }
  .brand-mark svg { width: 17px; height: 17px; }
  .brand-text strong { font-size: 16px; }
  .hero h1 { font-size: 29px; letter-spacing: -.5px; }
  .hero-mark { width: 74px; height: 74px; margin-bottom: 16px; }
  .hero-mark svg { width: 36px; height: 36px; }
  .hero-sub { font-size: 15.5px; }
  .hero-actions .btn { flex: 1 1 100%; }
  .hero-shot { max-width: 100%; border-radius: 12px; }
  .hero-stats { grid-template-columns: repeat(2, 1fr); }
  .os-strip .container { justify-content: flex-start; gap: 14px; }
  .platform-grid,
  .feature-grid,
  .steps,
  .blog-grid,
  .value-grid,
  .about-stats { grid-template-columns: 1fr; }
  .sidebar { grid-template-columns: 1fr; }
  .cta-band { padding: 34px 22px; border-radius: var(--radius); }
  .cta-actions .btn { flex: 1 1 100%; }
  .footer-grid { grid-template-columns: 1fr; gap: 26px; }
  .footer-bottom { flex-direction: column; align-items: flex-start; }
  .accordion .acc-btn { padding: 15px 16px; font-size: 14.5px; }
  .acc-panel .acc-body { padding: 0 16px 18px 16px; }
  .dl-card { padding: 22px 18px; }
  .dl-meta { grid-template-columns: 1fr 1fr; }
  .dl-actions .btn { flex: 1 1 100%; }
  .tabs { width: 100%; justify-content: center; }
  .tab-btn { padding: 7px 13px; font-size: 12.5px; }
  .faq-tools { padding: 12px; }
  .featured-post .fp-body { padding: 22px 18px; }
  .page-hero { padding: 32px 0 40px; }
  .back-top { right: 14px; bottom: 16px; width: 38px; height: 38px; }
  .footer-keywords { padding-bottom: 18px; }
}

/* ---------- 26. 文章详情 ---------- */
.article-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 300px;
  gap: 36px;
  align-items: start;
}
.article-card {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 38px 42px;
  box-shadow: var(--shadow-sm);
}
.article-cover {
  margin-bottom: 30px;
  border-radius: 10px;
  overflow: hidden;
  border: 1px solid var(--line);
  background: var(--soft-2);
}
.article-cover img { display: block; width: 100%; height: auto; }
.article-body { font-size: 16px; line-height: 1.95; color: #2b3a42; }
.article-body > p { margin-bottom: 18px; }
.article-body h2 {
  font-size: 24px;
  line-height: 1.45;
  margin: 38px 0 14px;
  scroll-margin-top: 92px;
  color: var(--ink);
}
.article-body h3 {
  font-size: 19px;
  margin: 26px 0 10px;
  scroll-margin-top: 92px;
  color: var(--ink);
}
.article-body ul,
.article-body ol { margin: 0 0 20px; padding-left: 22px; display: grid; gap: 8px; }
.article-body li { line-height: 1.85; }
.article-body strong { color: #0b2f45; }
.article-body a { color: var(--blue); text-decoration: underline; text-underline-offset: 3px; }
.article-body code {
  background: #f3f8fb;
  border: 1px solid #e3eef4;
  border-radius: 4px;
  padding: 1px 6px;
  font-size: 13px;
}
.article-tip {
  background: #f2fafd;
  border: 1px solid #d9ecf6;
  border-left: 3px solid var(--blue);
  border-radius: 8px;
  padding: 14px 18px;
  margin: 22px 0;
  font-size: 14.5px;
  line-height: 1.85;
  color: #33515f;
}
.article-table { width: 100%; border-collapse: collapse; margin: 18px 0 26px; font-size: 14px; }
.article-table th,
.article-table td { border: 1px solid #e4eef4; padding: 10px 12px; text-align: left; }
.article-table th { background: #f4fafc; font-weight: 600; }
.article-toc {
  position: sticky;
  top: 96px;
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 20px 22px;
  background: #fff;
}
.article-toc h3 { font-size: 14px; margin-bottom: 12px; color: var(--ink); }
.article-toc ol { padding-left: 18px; display: grid; gap: 9px; font-size: 13.5px; }
.article-toc a { color: var(--muted); }
.article-toc a:hover { color: var(--blue); }
.article-cta {
  margin-top: 34px;
  padding: 22px 24px;
  border: 1px solid #d9ecf6;
  background: #f5fbfd;
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  flex-wrap: wrap;
}
.article-cta h3 { font-size: 16px; margin-bottom: 4px; }
.article-cta p { font-size: 13.5px; color: var(--muted); margin: 0; }
.article-related { margin-top: 34px; display: grid; gap: 10px; }
.article-related h3 { font-size: 15px; margin-bottom: 4px; }
.article-related a {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  padding: 12px 14px;
  border: 1px solid var(--line);
  border-radius: 8px;
  font-size: 14px;
  color: var(--ink);
}
.article-related a:hover { border-color: #b9dcf0; color: var(--blue); }
.article-nav { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; margin-top: 26px; }
.article-nav a {
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 14px 16px;
  font-size: 13.5px;
  color: var(--muted);
  line-height: 1.6;
}
.article-nav a:hover { border-color: #b9dcf0; }
.article-nav span { display: block; font-size: 11.5px; color: var(--muted-2); margin-bottom: 4px; }

@media (max-width: 1080px) {
  .article-layout { grid-template-columns: 1fr; }
  .article-toc { position: static; order: -1; }
}
@media (max-width: 640px) {
  .article-card { padding: 22px 18px; }
  .article-body { font-size: 15.5px; line-height: 1.9; }
  .article-body h2 { font-size: 21px; }
  .article-nav { grid-template-columns: 1fr; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *,
  *::before,
  *::after {
    animation-duration: .01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .01ms !important;
  }
}

/* ---------- 27. 自适应与响应式设计框架 ----------
   断点约定：≥1200 大屏 / 1080 桌面 / 940 平板横屏 / 768 平板竖屏 / 640 手机 / 420 小屏
   策略：容器流式内边距 + 栅格自动填充 + 字号 clamp + 触屏友好尺寸
   ------------------------------------------------ */

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

img, svg, video, iframe { max-width: 100%; height: auto; }

/* 长链接、长代码不撑破容器 */
.article-body a,
.article-body code,
.footer-keywords { overflow-wrap: anywhere; }

/* 容器与章节间距随视口连续变化，不再依赖跳变 */
.container {
  padding-left: clamp(16px, 4vw, 22px);
  padding-right: clamp(16px, 4vw, 22px);
}
.hero { padding: clamp(46px, 6.5vw, 56px) 0 clamp(52px, 8vw, 68px); }
.page-hero { padding: clamp(28px, 4.5vw, 40px) 0 clamp(34px, 5.5vw, 48px); }
.section { padding: clamp(48px, 7vw, 76px) 0; }
.section.tight { padding: clamp(36px, 5vw, 56px) 0; }
.section-head { margin-bottom: clamp(26px, 4vw, 44px); }

/* 大屏放宽阅读宽度 */
@media (min-width: 1200px) {
  :root { --container: 1080px; }
  .hero-shot { max-width: 900px; }
}

/* 卡片栅格改为自动填充：列数随可用宽度连续变化，不出现半空列 */
.platform-grid { grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); }
.feature-grid { grid-template-columns: repeat(auto-fit, minmax(250px, 1fr)); }
.blog-grid { grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); }
.value-grid { grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); }
.steps { grid-template-columns: repeat(auto-fit, minmax(230px, 1fr)); }
.about-stats { grid-template-columns: repeat(auto-fit, minmax(180px, 1fr)); }
.sidebar { grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); }

/* 平板：压缩内边距与间距，保持双列呼吸感 */
@media (max-width: 940px) {
  .featured-post .fp-body { padding: 26px 24px; }
  .post-body { padding: 18px 16px 20px; }
  .feature-body { padding: 20px 18px 22px; }
  .platform-card { padding: 18px 16px; }
}

/* 平板竖屏：三列结构改为单列可读区 */
@media (max-width: 768px) {
  .featured-post { grid-template-columns: 1fr; }
  .sidebar { position: static; }
  .hero-shot { max-width: 100%; }
  .article-body h2 { font-size: 22px; }
}

/* 手机：表格、标签页横向滚动，避免整页横向溢出 */
@media (max-width: 640px) {
  .tabs {
    width: 100%;
    flex-wrap: nowrap;
    justify-content: flex-start;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    scrollbar-width: thin;
  }
  .tabs::-webkit-scrollbar { height: 4px; }
  .tabs::-webkit-scrollbar-thumb { background: #cfd9de; border-radius: 4px; }
  .tab-btn { flex: 0 0 auto; }
  .dl-tip { width: 100%; }

  .article-table {
    display: block;
    width: 100%;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    font-size: 13px;
  }
  .article-table th,
  .article-table td { padding: 9px 10px; min-width: 92px; }

  .btn { min-height: 44px; }
  .post-card { border-radius: 10px; }
}

/* 小屏：进一步压缩字号与间距 */
@media (max-width: 560px) {
  .hero h1 { font-size: clamp(26px, 8.2vw, 30px); }
  .hero-sub { font-size: 15px; }
  .section-title { font-size: 22px; }
  .page-hero h1 { font-size: 24px; line-height: 1.3; }
  .page-hero .ph-sub { font-size: 14.5px; }
  .article-card { padding: 24px 16px; }
  .article-body { font-size: 15px; line-height: 1.85; }
  .article-body h2 { font-size: 19px; margin: 28px 0 12px; }
  .article-cta { flex-direction: column; align-items: flex-start; padding: 18px 16px; }
  .article-cta .btn { width: 100%; }
  .article-toc { padding: 16px 18px; }
  .footer-keywords { font-size: 12px; line-height: 1.9; }
  .featured-post .fp-body { padding: 20px 16px; }
}

/* 超小屏 */
@media (max-width: 420px) {
  .hero h1 { font-size: 24px; letter-spacing: -.4px; }
  .hero-notes { gap: 6px 14px; font-size: 12.5px; }
  .dl-meta { grid-template-columns: 1fr 1fr; }
  .dl-meta > div { padding: 9px 10px; }
  .chip { font-size: 12.5px; padding: 6px 12px; }
}