/* ==========================================================================
   Spotube 官方网站样式表
   风格：扁平 · 现代 · 专业（蓝白浅色主题，品牌蓝主色）
   品牌主色 #2563DC（衍生自原电光蓝 #5D9BFF，浅色背景下保证对比度）
   ========================================================================== */

/* ---------- 设计令牌 ---------- */
:root {
  --bg: #F7FAFF;
  --bg-soft: #EDF3FC;
  --surface: #FFFFFF;
  --surface-2: #EAF1FB;
  --surface-3: #C9DBF4;
  --border: #DFE8F6;
  --border-strong: #A6BEE2;
  --text: #13233E;
  --text-muted: #5A6B87;
  --text-faint: #67799A;
  --primary: #2563DC;
  --primary-strong: #4E8DF2;
  --primary-ink: #FFFFFF;
  --primary-deep: #E4EFFD;
  --primary-tint: rgba(37, 99, 220, 0.08);
  --primary-tint-2: rgba(37, 99, 220, 0.15);
  --ok: #0E9F6E;
  --radius: 14px;
  --radius-sm: 10px;
  --container: 1160px;
  --header-h: 68px;
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", "Helvetica Neue", Arial, sans-serif;
  --mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, "Liberation Mono", monospace;
}

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

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

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font);
  font-size: 16px;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

body.is-locked { overflow: hidden; }

img { max-width: 100%; height: auto; display: block; }

a { color: var(--primary); text-decoration: none; }
a:hover { color: var(--primary-strong); }

h1, h2, h3, h4 { color: var(--text); line-height: 1.25; margin: 0 0 14px; letter-spacing: 0.01em; }
h1 { font-size: clamp(32px, 4.6vw, 50px); font-weight: 800; }
h2 { font-size: clamp(24px, 3.2vw, 33px); font-weight: 700; }
h3 { font-size: 19px; font-weight: 700; }
p { margin: 0 0 14px; color: var(--text-muted); }
ul, ol { margin: 0; padding: 0; }
strong { color: var(--text); font-weight: 700; }

.container {
  width: 100%;
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 24px;
}

/* 锚点跳转时避开吸顶头部 */
section[id], div[id], article[id] { scroll-margin-top: 84px; }

section { padding: clamp(60px, 8vw, 96px) 0; }
.section--alt { background: var(--bg-soft); border-top: 1px solid var(--border); border-bottom: 1px solid var(--border); }

.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  background: var(--primary);
  color: var(--primary-ink);
  padding: 10px 18px;
  border-radius: 0 0 var(--radius-sm) 0;
  font-weight: 700;
  z-index: 300;
}
.skip-link:focus { left: 0; color: var(--primary-ink); }

:focus-visible { outline: 2px solid var(--primary); outline-offset: 3px; border-radius: 4px; }

::selection { background: rgba(37, 99, 220, 0.32); color: #fff; }

/* ---------- 通用组件 ---------- */
.kicker {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--primary);
  margin: 0 0 16px;
}
.kicker::before {
  content: "";
  width: 22px;
  height: 2px;
  background: var(--primary);
}

.section-head { max-width: 720px; margin: 0 0 48px; }
.section-head p { font-size: 17px; }
.section-head--center { margin-left: auto; margin-right: auto; text-align: center; }
.section-head--center .kicker::before { display: none; }
.section-head--center .kicker { justify-content: center; }

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 12px 26px;
  border-radius: 999px;
  border: 1px solid transparent;
  font: inherit;
  font-size: 16px;
  font-weight: 700;
  cursor: pointer;
  transition: background 0.18s ease, color 0.18s ease, border-color 0.18s ease, transform 0.18s ease;
}
.btn--primary { background: var(--primary); color: var(--primary-ink); }
.btn--primary:hover { background: var(--primary-strong); color: var(--primary-ink); transform: translateY(-1px); }
.btn--ghost { background: transparent; color: var(--text); border-color: var(--border-strong); }
.btn--ghost:hover { border-color: var(--primary); color: var(--primary-strong); }
.btn--lg { padding: 15px 34px; font-size: 17px; }
.btn--sm { padding: 8px 18px; font-size: 14px; }
.btn--block { width: 100%; }

.chip {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 5px 14px;
  border-radius: 999px;
  background: var(--primary-tint);
  border: 1px solid rgba(37, 99, 220, 0.22);
  color: var(--primary);
  font-size: 13px;
  font-weight: 600;
}

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px;
}

.icon-badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 48px;
  height: 48px;
  border-radius: 12px;
  background: var(--primary-deep);
  border: 1px solid rgba(37, 99, 220, 0.2);
  color: var(--primary);
  margin-bottom: 18px;
}
.icon-badge .icon { width: 24px; height: 24px; }

.icon { width: 20px; height: 20px; fill: none; stroke: currentColor; stroke-width: 1.8; stroke-linecap: round; stroke-linejoin: round; }
.icon--fill { fill: currentColor; stroke: none; }

.link-more { font-weight: 700; display: inline-flex; align-items: center; gap: 6px; }
.link-more .icon { width: 16px; height: 16px; }

/* ---------- 顶部导航 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--header-h);
  background: rgba(255, 255, 255, 0.9);
  -webkit-backdrop-filter: saturate(150%) blur(12px);
  backdrop-filter: saturate(150%) blur(12px);
  border-bottom: 1px solid transparent;
  transition: border-color 0.25s ease, background 0.25s ease;
}
.site-header.is-scrolled { border-bottom-color: var(--border); background: rgba(255, 255, 255, 0.97); }

.header-inner { display: flex; align-items: center; justify-content: space-between; height: var(--header-h); }

.brand { display: inline-flex; align-items: center; gap: 11px; }
.brand__mark { display: block; width: 34px; height: 34px; border-radius: 50%; overflow: hidden; }
.brand__mark svg { display: block; }
.brand__name { font-size: 21px; font-weight: 800; color: var(--text); letter-spacing: 0.02em; }
.brand__name:hover { color: var(--text); }

.site-nav { display: flex; align-items: center; gap: 6px; }
.site-nav a:not(.btn) {
  padding: 8px 15px;
  border-radius: 8px;
  color: var(--text-muted);
  font-weight: 600;
  font-size: 15px;
  transition: color 0.18s, background 0.18s;
}
.site-nav a:not(.btn):hover { color: var(--text); background: rgba(37, 99, 220, 0.08); }
.site-nav a.is-active:not(.btn) { color: var(--primary); background: var(--primary-tint); }
.site-nav .btn { margin-left: 12px; padding: 9px 22px; font-size: 15px; }

.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 42px;
  height: 42px;
  padding: 9px;
  background: transparent;
  border: 1px solid var(--border-strong);
  border-radius: 10px;
  cursor: pointer;
}
.nav-toggle span { display: block; height: 2px; width: 100%; background: var(--text); border-radius: 2px; transition: transform 0.22s ease, opacity 0.22s ease; }
.nav-toggle[aria-expanded="true"] span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
.nav-toggle[aria-expanded="true"] span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ---------- Hero（首页） ---------- */
.hero { padding: clamp(48px, 7vw, 92px) 0 clamp(56px, 7vw, 88px); position: relative; overflow: hidden; }
.hero::before {
  content: "";
  position: absolute;
  right: -180px;
  top: -220px;
  width: 560px;
  height: 560px;
  border: 1.5px solid var(--surface-3);
  border-radius: 50%;
}
.hero::after {
  content: "";
  position: absolute;
  left: -220px;
  bottom: -260px;
  width: 460px;
  height: 460px;
  border: 1.5px solid var(--surface-3);
  border-radius: 50%;
}

.hero-inner { display: grid; grid-template-columns: 1.08fr 0.92fr; gap: 56px; align-items: center; position: relative; z-index: 1; }

.hero h1 { margin-bottom: 22px; }
.hero-sub { font-size: 18px; max-width: 560px; margin-bottom: 34px; }

.hero-actions { display: flex; flex-wrap: wrap; gap: 14px; margin-bottom: 38px; }

.hero-facts { display: flex; flex-wrap: wrap; gap: 10px 34px; list-style: none; }
.hero-facts li { color: var(--text-faint); font-size: 14px; }
.hero-facts strong { color: var(--primary); font-size: 17px; margin-right: 4px; }

.hero-media { margin: 0; position: relative; }
.hero-media img {
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: #0B1424;
  box-shadow: 0 18px 48px rgba(30, 84, 190, 0.18);
}
.hero-media figcaption { margin-top: 12px; font-size: 13px; color: var(--text-faint); text-align: center; }

/* ---------- 数据统计条 ---------- */
.stats { padding: 0 0 clamp(56px, 7vw, 88px); }
.stats-inner {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1px;
  background: var(--border);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
}
.stat { background: var(--surface); padding: 26px 24px; }
.stat__num { font-size: clamp(26px, 3vw, 34px); font-weight: 800; color: var(--primary-strong); line-height: 1.2; }
.stat__label { font-size: 14px; color: var(--text-muted); margin-top: 4px; }
.stat__note { font-size: 12.5px; color: var(--text-faint); margin-top: 2px; }

/* ---------- 核心优势 ---------- */
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; }
.adv-card { transition: border-color 0.2s ease, transform 0.2s ease; }
.adv-card:hover { border-color: var(--border-strong); transform: translateY(-3px); }
.adv-card h3 { margin-bottom: 10px; }
.adv-card p { margin: 0; font-size: 15px; }

/* ---------- 使用场景 ---------- */
.scenario-list { display: grid; gap: 22px; }
.scenario {
  display: grid;
  grid-template-columns: 64px 1fr;
  gap: 22px;
  align-items: start;
}
.scenario .icon-badge { margin: 0; width: 56px; height: 56px; border-radius: 14px; }
.scenario .icon-badge .icon { width: 27px; height: 27px; }
.scenario__tag { font-size: 13px; font-weight: 700; color: var(--primary); letter-spacing: 0.08em; margin: 0 0 6px; }
.scenario h3 { margin-bottom: 8px; }
.scenario p { margin: 0 0 14px; font-size: 15px; }
.scenario__tags { display: flex; flex-wrap: wrap; gap: 8px; }

/* ---------- 承诺/信任 ---------- */
.promise-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; }
.promise { text-align: center; padding: 30px 24px; }
.promise .icon-badge { margin: 0 auto 16px; }
.promise h3 { font-size: 17px; margin-bottom: 8px; }
.promise p { margin: 0; font-size: 14.5px; }

/* ---------- 版本速览 ---------- */
.version-peek { display: grid; grid-template-columns: 1.2fr 0.8fr; gap: 40px; align-items: center; }
.version-peek__list { list-style: none; display: grid; gap: 12px; margin-top: 6px; }
.version-peek__list li { display: flex; gap: 10px; align-items: flex-start; color: var(--text-muted); font-size: 15px; }
.version-peek__list .icon { flex: none; width: 18px; height: 18px; margin-top: 5px; color: var(--primary); }
.version-badge {
  display: inline-flex;
  flex-direction: column;
  gap: 6px;
  padding: 26px;
  text-align: center;
}
.version-badge .v { font-size: 40px; font-weight: 800; color: var(--primary-strong); line-height: 1.1; }
.version-badge .d { color: var(--text-muted); font-size: 14px; }

/* ---------- CTA ---------- */
.cta-band { background: var(--bg-soft); border-top: 1px solid var(--border); border-bottom: 1px solid var(--border); }
.cta-inner { text-align: center; max-width: 640px; margin: 0 auto; }
.cta-inner p { font-size: 17px; }
.cta-actions { display: flex; justify-content: center; flex-wrap: wrap; gap: 14px; margin-top: 28px; }

/* ---------- 子页头 ---------- */
.page-hero { padding: clamp(44px, 6vw, 72px) 0 clamp(36px, 5vw, 56px); position: relative; overflow: hidden; }
.page-hero::after {
  content: "";
  position: absolute;
  right: -160px;
  top: -180px;
  width: 420px;
  height: 420px;
  border: 1.5px solid var(--surface-3);
  border-radius: 50%;
}
.page-hero h1 { max-width: 780px; margin-bottom: 18px; }
.page-hero .lead { font-size: 17.5px; max-width: 720px; margin: 0; }

.breadcrumb { display: flex; flex-wrap: wrap; align-items: center; gap: 10px; padding-top: 18px; font-size: 14px; color: var(--text-faint); }
.breadcrumb a { color: var(--text-muted); }
.breadcrumb a:hover { color: var(--primary-strong); }
.breadcrumb em { font-style: normal; color: var(--text); }

/* ---------- 功能页 ---------- */
.feature-block { display: grid; grid-template-columns: 0.9fr 1.1fr; gap: 48px; align-items: center; }
.feature-block + .feature-block { margin-top: 64px; }
.feature-block--flip { grid-template-columns: 1.1fr 0.9fr; }
.feature-block--flip .feature-media { order: -1; }
.feature-media {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px;
}
.feature-media ul { list-style: none; display: grid; gap: 12px; }
.feature-media li { display: flex; gap: 10px; align-items: flex-start; color: var(--text-muted); font-size: 14.5px; }
.feature-media .icon { flex: none; width: 18px; height: 18px; margin-top: 5px; color: var(--primary); }
.feature-copy h2 { margin-bottom: 14px; }
.feature-copy p { font-size: 16px; }
.feature-copy .chip { margin-bottom: 14px; }

.compare-table-wrap { overflow-x: auto; border: 1px solid var(--border); border-radius: var(--radius); }
table.compare { width: 100%; border-collapse: collapse; min-width: 640px; background: var(--surface); }
table.compare th, table.compare td { padding: 15px 18px; text-align: left; font-size: 15px; border-bottom: 1px solid var(--border); }
table.compare thead th { background: var(--surface-2); color: var(--text); font-weight: 700; }
table.compare tbody tr:last-child th, table.compare tbody tr:last-child td { border-bottom: none; }
table.compare td.yes { color: var(--primary); font-weight: 700; }
table.compare td.no { color: var(--text-faint); }
table.compare .icon { width: 17px; height: 17px; vertical-align: -3px; margin-right: 7px; }
table.compare caption { caption-side: bottom; text-align: left; padding: 14px 18px; color: var(--text-faint); font-size: 13px; }

.tech-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 18px; }
.tech-card { padding: 22px; }
.tech-card h3 { display: flex; align-items: center; gap: 10px; font-size: 16px; margin-bottom: 6px; }
.tech-card h3 .icon { width: 19px; height: 19px; color: var(--primary); }
.tech-card p { margin: 0; font-size: 14px; }

/* ---------- 下载页 ---------- */
.dl-meta { display: flex; flex-wrap: wrap; gap: 10px; margin: 0 0 34px; }

.os-tip {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 13px 18px;
  border: 1px solid rgba(37, 99, 220, 0.3);
  background: var(--primary-tint);
  border-radius: var(--radius-sm);
  color: var(--primary);
  font-size: 14.5px;
  margin-bottom: 30px;
}
.os-tip .icon { flex: none; width: 18px; height: 18px; }

.platform-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 22px; }
.platform-card { padding: 28px; }
.platform-card.is-recommended { border-color: rgba(37, 99, 220, 0.55); background: var(--primary-tint); }
.plat-head { display: flex; align-items: center; gap: 14px; margin-bottom: 8px; }
.plat-head .icon-badge { margin: 0; width: 46px; height: 46px; }
.plat-head h3 { margin: 0; font-size: 20px; }
.plat-head small { display: block; color: var(--text-faint); font-weight: 400; font-size: 13px; margin-top: 2px; }
.plat-desc { font-size: 14.5px; margin: 8px 0 16px; }
.plat-links { display: grid; gap: 10px; }
.dl-link {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 11px 16px;
  border: 1px solid var(--border-strong);
  border-radius: var(--radius-sm);
  color: var(--text);
  font-weight: 600;
  font-size: 14.5px;
  transition: border-color 0.18s, color 0.18s, background 0.18s;
}
.dl-link:hover { border-color: var(--primary); color: var(--primary-strong); background: var(--primary-tint); }
.dl-link .icon { width: 17px; height: 17px; flex: none; }
.dl-link--main { background: var(--primary); border-color: var(--primary); color: var(--primary-ink); }
.dl-link--main:hover { background: var(--primary-strong); color: var(--primary-ink); border-color: var(--primary-strong); }
.plat-req { margin: 16px 0 0; font-size: 13px; color: var(--text-faint); }

.cmd-block { margin-top: 12px; }
.cmd-block .cmd-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 9px 14px;
  background: #15263F;
  border: 1px solid #24395C;
  border-bottom: none;
  border-radius: var(--radius-sm) var(--radius-sm) 0 0;
  font-size: 13px;
  color: #C9D8F4;
}
.cmd-copy {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: transparent;
  border: 1px solid #3C5580;
  color: #A9BFE0;
  font: inherit;
  font-size: 12.5px;
  padding: 4px 10px;
  border-radius: 6px;
  cursor: pointer;
  transition: color 0.15s, border-color 0.15s;
}
.cmd-copy:hover { color: #9CC0FF; border-color: #5B96F0; }
.cmd-copy .icon { width: 14px; height: 14px; }
.cmd-block pre {
  margin: 0;
  background: #0C1A2E;
  border: 1px solid #24395C;
  border-radius: 0 0 var(--radius-sm) var(--radius-sm);
  padding: 14px 16px;
  overflow-x: auto;
  font-family: var(--mono);
  font-size: 13.5px;
  line-height: 1.7;
  color: #C4D6F2;
}
.cmd-block pre .c { color: #8AA2C8; }

/* 二维码区 */
.qr-section { text-align: center; }
.qr-grid { display: flex; justify-content: center; gap: 26px; flex-wrap: wrap; margin: 42px 0 30px; }
.qr-card {
  background: #FFFFFF;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 22px 22px 18px;
  width: 250px;
}
.qr-card img { width: 206px; height: 206px; margin: 0 auto; image-rendering: pixelated; }
.qr-card__tag {
  display: inline-block;
  margin-top: 14px;
  padding: 4px 14px;
  border-radius: 999px;
  background: var(--primary-deep);
  color: var(--primary);
  font-size: 13.5px;
  font-weight: 700;
}
.qr-card p { margin: 10px 0 0; font-size: 13px; color: #4A5568; line-height: 1.6; }
.qr-note { font-size: 13.5px; color: var(--text-faint); max-width: 620px; margin: 0 auto; }

/* 安装指引 Tabs */
.tabs { border: 1px solid var(--border); border-radius: var(--radius); background: var(--surface); overflow: hidden; }
.tabs__nav { display: flex; flex-wrap: wrap; gap: 0; border-bottom: 1px solid var(--border); background: var(--bg-soft); }
.tab-btn {
  padding: 13px 22px;
  background: transparent;
  border: none;
  border-bottom: 2px solid transparent;
  color: var(--text-muted);
  font: inherit;
  font-weight: 600;
  font-size: 14.5px;
  cursor: pointer;
  transition: color 0.15s, border-color 0.15s;
}
.tab-btn:hover { color: var(--text); }
.tab-btn.is-active { color: var(--primary); border-bottom-color: var(--primary); }
.tab-panel { padding: 28px; }
.tab-panel[hidden] { display: none; }
.step-list { list-style: none; counter-reset: step; display: grid; gap: 18px; }
.step-list li { counter-increment: step; display: grid; grid-template-columns: 34px 1fr; gap: 14px; align-items: start; }
.step-list li::before {
  content: counter(step);
  display: flex;
  align-items: center;
  justify-content: center;
  width: 34px;
  height: 34px;
  border-radius: 50%;
  background: var(--primary-deep);
  border: 1px solid rgba(37, 99, 220, 0.3);
  color: var(--primary);
  font-weight: 700;
  font-size: 14px;
}
.step-list p { margin: 2px 0 0; font-size: 15px; }
.step-list code {
  font-family: var(--mono);
  font-size: 13.5px;
  background: #0C1A2E;
  border: 1px solid #24395C;
  border-radius: 6px;
  padding: 2px 8px;
  color: #C4D6F2;
}

/* 更新日志 */
.changelog { border: 1px solid var(--border); border-radius: var(--radius); background: var(--surface); overflow: hidden; }
.changelog__item { padding: 24px 28px; border-bottom: 1px solid var(--border); }
.changelog__item:last-child { border-bottom: none; }
.changelog__head { display: flex; flex-wrap: wrap; align-items: center; gap: 12px; margin-bottom: 10px; }
.changelog__tag { font-size: 18px; font-weight: 800; color: var(--primary); }
.changelog__date { font-size: 13.5px; color: var(--text-faint); }
.changelog__badge { padding: 3px 11px; border-radius: 999px; font-size: 12px; font-weight: 700; background: var(--primary-tint); color: var(--primary); border: 1px solid rgba(37, 99, 220, 0.25); }
.changelog__item ul { list-style: none; display: grid; gap: 8px; }
.changelog__item li { display: flex; gap: 10px; color: var(--text-muted); font-size: 14.5px; }
.changelog__item li::before { content: ""; flex: none; width: 6px; height: 6px; border-radius: 50%; background: var(--primary); margin-top: 10px; }

/* ---------- 关于页 ---------- */
.timeline { position: relative; padding-left: 34px; }
.timeline::before { content: ""; position: absolute; left: 8px; top: 8px; bottom: 8px; width: 2px; background: var(--border-strong); }
.timeline__item { position: relative; padding-bottom: 34px; }
.timeline__item:last-child { padding-bottom: 0; }
.timeline__item::before {
  content: "";
  position: absolute;
  left: -34px;
  top: 7px;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--primary-deep);
  border: 2px solid var(--primary);
}
.timeline__time { font-size: 13px; font-weight: 700; color: var(--primary); letter-spacing: 0.05em; margin-bottom: 4px; }
.timeline__item h3 { font-size: 17px; margin-bottom: 6px; }
.timeline__item p { margin: 0; font-size: 14.5px; }

.team-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 20px; }
.team-card { display: flex; gap: 18px; align-items: flex-start; padding: 24px; }
.team-avatar {
  flex: none;
  width: 52px;
  height: 52px;
  border-radius: 50%;
  background: var(--primary-deep);
  border: 1px solid rgba(37, 99, 220, 0.3);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--primary);
  font-weight: 800;
  font-size: 19px;
}
.team-card h3 { font-size: 16.5px; margin-bottom: 2px; }
.team-card .role { font-size: 13px; color: var(--primary); font-weight: 600; margin-bottom: 6px; }
.team-card p { margin: 0; font-size: 14px; }

.value-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 20px; }
.value-card { padding: 24px; }
.value-card h3 { display: flex; align-items: center; gap: 10px; font-size: 16px; }
.value-card h3 .icon { width: 19px; height: 19px; color: var(--primary); }
.value-card p { margin: 0; font-size: 14.5px; }

/* ---------- FAQ 页 ---------- */
.faq-cat { margin-bottom: 46px; }
.faq-cat > h2 { font-size: 22px; margin-bottom: 20px; display: flex; align-items: center; gap: 12px; }
.faq-cat > h2 .icon { width: 21px; height: 21px; color: var(--primary); }
details.faq-item {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  margin-bottom: 12px;
  overflow: hidden;
  transition: border-color 0.18s;
}
details.faq-item[open] { border-color: var(--border-strong); }
details.faq-item summary {
  list-style: none;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 17px 20px;
  font-weight: 700;
  font-size: 15.5px;
  color: var(--text);
}
details.faq-item summary::-webkit-details-marker { display: none; }
details.faq-item summary:hover { color: var(--primary-strong); }
details.faq-item summary .chev { flex: none; width: 18px; height: 18px; color: var(--text-faint); transition: transform 0.2s ease, color 0.2s; }
details.faq-item[open] summary .chev { transform: rotate(180deg); color: var(--primary); }
.faq-body { padding: 0 20px 20px; font-size: 15px; color: var(--text-muted); }
.faq-body p { margin: 0; }
.faq-body p + p { margin-top: 10px; }
.faq-body a { font-weight: 600; }

/* ---------- 页脚 ---------- */
.site-footer { border-top: 1px solid var(--border); background: var(--bg-soft); padding: 56px 0 30px; margin-top: 0; }
.footer-grid { display: grid; grid-template-columns: 1.6fr 1fr 1fr 1fr; gap: 40px; margin-bottom: 42px; }
.footer-brand .brand { margin-bottom: 14px; }
.footer-brand > p { font-size: 14px; max-width: 320px; }
.footer-social { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 16px; }
.footer-social a {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 6px 13px;
  border: 1px solid var(--border-strong);
  border-radius: 999px;
  color: var(--text-muted);
  font-size: 13px;
  font-weight: 600;
  transition: color 0.15s, border-color 0.15s;
}
.footer-social a:hover { color: var(--primary-strong); border-color: var(--primary); }
.footer-social .icon { width: 15px; height: 15px; }
.footer-col h3 { font-size: 14px; color: var(--text); margin-bottom: 14px; letter-spacing: 0.06em; }
.footer-col ul { list-style: none; display: grid; gap: 9px; }
.footer-col a { color: var(--text-muted); font-size: 14px; }
.footer-col a:hover { color: var(--primary-strong); }
.footer-bottom { border-top: 1px solid var(--border); padding-top: 24px; display: grid; gap: 6px; }
.footer-bottom p { margin: 0; font-size: 12.5px; color: var(--text-faint); }
.footer-bottom a { color: var(--text-faint); }
.footer-bottom a:hover { color: var(--primary-strong); }

/* ---------- 下载弹窗 ---------- */
.modal { position: fixed; inset: 0; z-index: 200; display: flex; align-items: center; justify-content: center; padding: 22px;  left: 0;
  right: 0;
  top: 0;
  bottom: 0;}
  button { outline: none } 
.modal[hidden] { display: none; }
.modal__backdrop { position: absolute; inset: 0; background: rgba(16, 27, 48, 0.6); }
.modal__panel {
  position: relative;
  width: 100%;
  max-width: 580px;
  max-height: calc(100vh - 44px);
  overflow-y: auto;
  background: var(--surface);
  border: 1px solid var(--border-strong);
  border-radius: 18px;
  padding: 34px 34px 28px;
  animation: modalIn 0.22s ease;
}
@keyframes modalIn {
  from { opacity: 0; transform: translateY(14px) scale(0.985); }
  to { opacity: 1; transform: none; }
}
.modal__close {
  position: absolute;
  top: 16px;
  right: 16px;
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: transparent;
  border: 1px solid var(--border-strong);
  border-radius: 10px;
  color: var(--text-muted);
  cursor: pointer;
  transition: color 0.15s, border-color 0.15s;
}
.modal__close:hover { color: var(--text); border-color: var(--primary); }
.modal__close .icon { width: 16px; height: 16px; }
.modal__head h2 { font-size: 24px; margin-bottom: 6px; }
.modal__meta { font-size: 13.5px; color: var(--text-muted); margin: 0 0 22px; }
.modal__qr { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; margin-bottom: 22px; }
.qr-mini { background: #fff; border: 1px solid var(--border); border-radius: var(--radius-sm); padding: 14px 12px 12px; text-align: center; }
.qr-mini img { width: 100%; max-width: 178px; margin: 0 auto; image-rendering: pixelated; }
.qr-mini__tag { display: block; margin-top: 10px; font-size: 13px; font-weight: 700; color: #1A2433; }
.qr-mini p { margin: 4px 0 0; font-size: 12px; color: #4A5568; line-height: 1.55; }
.modal__divider {
  display: flex;
  align-items: center;
  gap: 14px;
  color: var(--text-faint);
  font-size: 12.5px;
  margin: 0 0 16px;
}
.modal__divider::before, .modal__divider::after { content: ""; flex: 1; height: 1px; background: var(--border); }
.modal__platforms { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; margin-bottom: 18px; }
.plat-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 9px;
  padding: 11px 12px;
  border: 1px solid var(--border-strong);
  border-radius: var(--radius-sm);
  color: var(--text);
  font-weight: 600;
  font-size: 14px;
  transition: border-color 0.15s, color 0.15s, background 0.15s;
}
.plat-btn:hover { border-color: var(--primary); color: var(--primary-strong); background: var(--primary-tint); }
.plat-btn .icon { width: 16px; height: 16px; flex: none; }
.modal__note { margin: 0; font-size: 12px; color: var(--text-muted); text-align: center; }

/* ---------- 动效 ---------- */
.reveal { opacity: 0; transform: translateY(18px); transition: opacity 0.55s ease, transform 0.55s ease; }
.reveal.is-visible { opacity: 1; transform: none; }
.reveal--d1 { transition-delay: 0.08s; }
.reveal--d2 { transition-delay: 0.16s; }
.reveal--d3 { transition-delay: 0.24s; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation-duration: 0.01ms !important; transition-duration: 0.01ms !important; }
  .reveal { opacity: 1; transform: none; }
}

/* ---------- 响应式 ---------- */
@media (max-width: 1020px) {
  .hero-inner { grid-template-columns: 1fr; gap: 40px; }
  .hero-media { max-width: 560px; }
  .grid-3, .promise-grid { grid-template-columns: repeat(2, 1fr); }
  .stats-inner { grid-template-columns: repeat(2, 1fr); }
  .version-peek { grid-template-columns: 1fr; gap: 26px; }
  .feature-block, .feature-block--flip { grid-template-columns: 1fr; gap: 30px; }
  .feature-block--flip .feature-media { order: 0; }
  .platform-grid, .team-grid, .value-grid, .tech-grid { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr 1fr; gap: 30px; }
}

@media (max-width: 720px) {
  .nav-toggle { display: flex; }
  .site-nav {
    position: fixed;
    top: var(--header-h);
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: stretch;
    gap: 4px;
    background: var(--bg);
    border-bottom: 1px solid var(--border);
    padding: 18px 24px 26px;
    transform: translateY(-8px);
    opacity: 0;
    visibility: hidden;
    transition: transform 0.2s ease, opacity 0.2s ease, visibility 0.2s;
  }
  .site-nav.is-open { transform: none; opacity: 1; visibility: visible; }
  .site-nav a:not(.btn) { padding: 12px 14px; font-size: 16px; }
  .site-nav .btn { margin: 10px 0 0; justify-content: center; }
  .grid-3, .promise-grid { grid-template-columns: 1fr; }
  .stats-inner { grid-template-columns: 1fr 1fr; }
  .scenario { grid-template-columns: 1fr; gap: 14px; }
  .scenario .icon-badge { width: 48px; height: 48px; }
  .modal__panel { padding: 26px 20px 22px; }
  .modal__qr { grid-template-columns: 1fr; }
  .modal__platforms { grid-template-columns: 1fr; }
  .qr-grid { flex-direction: column; align-items: center; }
  .footer-grid { grid-template-columns: 1fr; }
  .hero-actions .btn { width: 100%; }
  .cta-actions .btn { width: 100%; }
}