/* ==========================================================================
   抖漫动漫 官网 · style.css
   主题：晴空蓝 × 活力橙 · 版式：左文右图 Hero / 六功能卡 / 海报双卡
   ========================================================================== */

:root {
  --blue-900: #0d2233;
  --blue-800: #12324a;
  --blue-700: #1a4a6e;
  --blue-600: #1e6fa8;
  --blue-500: #2f9de8;
  --blue-400: #5fb8f2;
  --blue-300: #93d0f7;
  --blue-200: #c3e5fb;
  --blue-100: #e2f3fd;
  --blue-50: #f3faff;
  --orange-500: #ff7a1a;
  --orange-400: #ff9547;
  --orange-100: #ffe9d6;
  --ink: #10263a;
  --ink-2: #47627a;
  --ink-3: #7d96ab;
  --card: #ffffff;
  --line: #e3eef7;
  --line-dark: rgba(255, 255, 255, .14);
  --radius: 18px;
  --shadow-sm: 0 1px 2px rgba(16, 38, 58, .06);
  --shadow-md: 0 14px 36px -16px rgba(16, 38, 58, .3);
  --container: 1160px;
  --nav-h: 68px;
  --font: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", "Helvetica Neue", Arial, sans-serif;
}

/* ---------- 基础 ---------- */
* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  font-family: var(--font);
  font-size: 16px;
  line-height: 1.75;
  color: var(--ink);
  background: var(--blue-50);
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}
img { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
ul { list-style: none; }
button { font-family: inherit; }
:focus-visible { outline: 2px solid var(--blue-500); outline-offset: 2px; }

.container { width: min(var(--container), 92%); margin: 0 auto; }
section[id] { scroll-margin-top: calc(var(--nav-h) + 12px); }

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  border: 1px solid transparent;
  border-radius: 999px;
  font-size: 16px;
  font-weight: 600;
  line-height: 1;
  padding: 13px 30px;
  cursor: pointer;
  transition: background-color .2s ease, color .2s ease, border-color .2s ease, transform .2s ease, box-shadow .2s ease;
  white-space: nowrap;
}
.btn:active { transform: scale(.98); }
.btn-primary { background: var(--blue-600); color: #fff; box-shadow: 0 8px 20px -10px rgba(30, 111, 168, .55); }
.btn-primary:hover { background: var(--blue-700); }
.btn-accent { background: var(--orange-500); color: #fff; box-shadow: 0 8px 20px -10px rgba(255, 122, 26, .55); }
.btn-accent:hover { background: #e56610; }
.btn-light { background: #fff; color: var(--blue-700); }
.btn-light:hover { background: var(--blue-50); }
.btn-lg { padding: 16px 38px; font-size: 17px; }
.btn-sm { padding: 10px 20px; font-size: 14px; }

/* ---------- 导航 ---------- */
.site-nav {
  position: fixed;
  inset: 0 0 auto 0;
  z-index: 100;
  height: var(--nav-h);
  background: rgba(243, 250, 255, .88);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border-bottom: 1px solid transparent;
  transition: border-color .25s ease, box-shadow .25s ease;
}
.site-nav.scrolled { border-bottom-color: var(--line); box-shadow: var(--shadow-sm); }
.nav-inner { height: var(--nav-h); display: flex; align-items: center; justify-content: space-between; gap: 24px; }
.brand { display: inline-flex; align-items: center; gap: 10px; }
.brand-icon { width: 34px; height: 34px; border-radius: 9px; object-fit: cover; }
.brand-name { font-size: 20px; font-weight: 800; letter-spacing: .01em; color: var(--blue-700); }

.nav-links { display: flex; align-items: center; gap: 4px; }
.nav-link {
  position: relative;
  padding: 8px 14px;
  font-size: 15px;
  color: var(--ink-2);
  border-radius: 999px;
  transition: color .2s ease, background-color .2s ease;
}
.nav-link:hover { color: var(--blue-700); background: var(--blue-50); }
.nav-link.active { color: var(--blue-600); font-weight: 600; }
.nav-actions { display: flex; align-items: center; gap: 12px; }

.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 42px;
  height: 42px;
  padding: 10px;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: #fff;
  cursor: pointer;
}
.nav-toggle span { display: block; height: 2px; border-radius: 2px; background: var(--blue-700); transition: transform .25s ease, opacity .25s 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：左文右图 ---------- */
.hero {
  padding: calc(var(--nav-h) + 56px) 0 0;
  background:
    radial-gradient(560px 300px at 88% 8%, rgba(255, 255, 255, .28), transparent 62%),
    radial-gradient(480px 280px at 4% 92%, rgba(147, 208, 247, .5), transparent 60%),
    linear-gradient(135deg, var(--blue-500), var(--blue-400));
  overflow: hidden;
}
.hero-inner {
  display: grid;
  grid-template-columns: 1.2fr .8fr;
  align-items: center;
  gap: 40px;
}
.hero-copy { padding: 30px 0 40px; }
.hero-kicker {
  display: inline-block;
  padding: 6px 14px;
  border: 1.5px solid rgba(255, 255, 255, .7);
  border-radius: 999px;
  background: rgba(255, 255, 255, .16);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: .12em;
  color: #fff;
}
.hero h1 {
  margin-top: 22px;
  font-size: clamp(2.1rem, 4.8vw, 3.3rem);
  line-height: 1.22;
  letter-spacing: -.01em;
  color: #fff;
}
.hero-sub { margin-top: 18px; max-width: 540px; color: rgba(255, 255, 255, .9); font-size: 16.5px; }
.hero-tags { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 22px; }
.hero-tags li {
  padding: 7px 16px;
  border: 1px solid rgba(255, 255, 255, .55);
  border-radius: 999px;
  background: rgba(255, 255, 255, .18);
  font-size: 13.5px;
  font-weight: 600;
  color: #fff;
}
.hero-actions { margin-top: 28px; }
.hero-note { margin-top: 16px; font-size: 13px; color: rgba(255, 255, 255, .78); }

.hero-phone-wrap {
  position: relative;
  display: flex;
  justify-content: flex-end;
  align-items: flex-end;
}
.hero-phone-wrap::before {
  content: "";
  position: absolute;
  bottom: 0; right: 50%;
  transform: translateX(50%);
  width: 300px; height: 300px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(255, 255, 255, .35), transparent 68%);
  pointer-events: none;
}
.phone-hero { width: 262px; margin-bottom: -6px; }

/* 数据条 */
.hero-stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 18px;
  margin-top: 40px;
  padding: 26px 8px;
  background: rgba(255, 255, 255, .6);
  border-radius: 20px 20px 0 0;
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
}
.hero-stat { text-align: center; }
.hero-stat dt { font-size: 26px; font-weight: 800; color: var(--blue-700); line-height: 1.2; }
.hero-stat dd { font-size: 13px; color: rgba(16, 38, 58, .68); margin-top: 2px; }

/* ---------- 手机相框 ---------- */
.phone {
  position: relative;
  border-radius: 42px;
  border: 10px solid var(--blue-900);
  background: var(--blue-900);
  box-shadow: 0 18px 44px -16px rgba(13, 34, 51, .5);
  overflow: hidden;
  aspect-ratio: 9 / 19;
  flex: none;
}
.phone-top {
  position: absolute;
  top: 8px; left: 50%;
  transform: translateX(-50%);
  width: 84px; height: 20px;
  border-radius: 999px;
  background: var(--blue-900);
  z-index: 2;
}
.phone img { width: 100%; height: 100%; object-fit: cover; }

/* ---------- 区块通用 ---------- */
.section { padding: 92px 0; }
.section-alt { background: #fff; }
.section-cta { background: var(--blue-50); }
.section-head { max-width: 700px; margin: 0 auto 52px; text-align: center; }
.section-label {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 12px;
  font-weight: 700;
  letter-spacing: .1em;
  color: var(--blue-600);
  margin-bottom: 12px;
}
.section-label::before { content: ""; width: 18px; height: 2px; border-radius: 2px; background: var(--blue-400); }
.section-head h2 { font-size: clamp(1.6rem, 3vw, 2.15rem); line-height: 1.3; color: var(--blue-800); letter-spacing: -.01em; }
.section-lead { margin-top: 12px; color: var(--ink-2); font-size: 15.5px; }

/* ---------- 功能特色：卡片 ---------- */
.feature-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; max-width: 980px; margin: 0 auto; }
.feature-card {
  padding: 30px 26px 26px;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  transition: transform .25s ease, border-color .25s ease, box-shadow .25s ease;
}
.feature-card:hover { transform: translateY(-3px); border-color: var(--blue-300); box-shadow: var(--shadow-md); }
.feature-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 46px; height: 46px;
  border-radius: 12px;
  background: var(--blue-100);
  color: var(--blue-600);
  margin-bottom: 16px;
}
.feature-icon svg { width: 24px; height: 24px; }
.feature-card h3 { font-size: 17px; color: var(--blue-800); margin-bottom: 8px; }
.feature-card p { font-size: 14px; color: var(--ink-2); line-height: 1.7; }

/* ---------- 热门推荐：海报双卡 ---------- */
.hot-pair { display: grid; grid-template-columns: repeat(2, 1fr); gap: 24px; max-width: 960px; margin: 0 auto; }
.hot-card {
  position: relative;
  border-radius: 20px;
  overflow: hidden;
  border: 1px solid var(--line);
  background: #fff;
  aspect-ratio: 5 / 4;
  transition: transform .25s ease, box-shadow .25s ease;
}
.hot-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-md); }
.hot-card img { width: 100%; height: 100%; object-fit: cover; object-position: center top; }
.hot-caption {
  position: absolute;
  left: 0; right: 0; bottom: 0;
  padding: 28px 22px 20px;
  background: linear-gradient(to top, rgba(13, 34, 51, .82), rgba(13, 34, 51, 0));
  color: #fff;
}
.hot-caption h3 { font-size: 17px; margin-bottom: 4px; }
.hot-caption p { font-size: 13.5px; color: rgba(255, 255, 255, .78); }

/* ---------- 用户评价：四宫格 ---------- */
.voices-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 18px; }
.voice-card {
  position: relative;
  padding: 28px 22px 22px;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}
.voice-card::before {
  content: "“";
  position: absolute;
  top: 6px; right: 16px;
  font-size: 52px;
  line-height: 1;
  color: var(--blue-200);
  font-family: Georgia, serif;
}
.voice-card p { font-size: 14.5px; color: var(--ink); line-height: 1.8; }
.voice-card footer { margin-top: 14px; font-size: 12.5px; color: var(--ink-3); }

/* ---------- FAQ：手风琴 ---------- */
.faq-list { display: flex; flex-direction: column; gap: 14px; max-width: 820px; margin: 0 auto; }
.faq-item {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  transition: border-color .2s ease;
}
.faq-item.open { border-color: var(--blue-400); }
.faq-q {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  width: 100%;
  padding: 20px 24px;
  background: transparent;
  border: 0;
  font-size: 15.5px;
  font-weight: 600;
  color: var(--blue-800);
  text-align: left;
  cursor: pointer;
}
.faq-q svg { width: 20px; height: 20px; color: var(--blue-500); flex: none; transition: transform .3s ease; }
.faq-item.open .faq-q svg { transform: rotate(45deg); }
.faq-a { max-height: 0; overflow: hidden; transition: max-height .35s ease; }
.faq-a p { padding: 0 24px 20px; font-size: 14.5px; color: var(--ink-2); }

/* ---------- 下载 CTA：通栏 ---------- */
.cta-full {
  position: relative;
  padding: 64px 32px;
  text-align: center;
  border-radius: 28px;
  background:
    radial-gradient(480px 240px at 12% 0%, rgba(255, 255, 255, .28), transparent 62%),
    radial-gradient(420px 220px at 90% 100%, rgba(147, 208, 247, .5), transparent 60%),
    linear-gradient(135deg, var(--blue-600), var(--blue-400));
  color: #fff;
  overflow: hidden;
}
.cta-deco { position: absolute; inset: 0; pointer-events: none; }
.cta-deco::before, .cta-deco::after {
  content: "";
  position: absolute;
  border-radius: 50%;
  border: 1.5px solid rgba(255, 255, 255, .22);
}
.cta-deco::before { width: 240px; height: 240px; left: -70px; top: -90px; }
.cta-deco::after { width: 170px; height: 170px; right: -50px; bottom: -70px; }
.cta-full h2 { font-size: clamp(1.55rem, 3vw, 2.15rem); line-height: 1.4; letter-spacing: -.01em; }
.cta-full p { margin-top: 14px; color: rgba(255, 255, 255, .85); }
.cta-full .btn { margin-top: 28px; }
.cta-note { font-size: 12.5px; color: rgba(255, 255, 255, .66) !important; margin-top: 16px !important; }

/* ---------- 页脚 ---------- */
.site-footer { background: var(--blue-900); color: rgba(226, 243, 253, .78); padding-top: 60px; }
.footer-inner { display: grid; grid-template-columns: 1.6fr 1fr 1fr 1.2fr; gap: 40px; padding-bottom: 44px; }
.brand-footer .brand-name { color: #fff; }
.footer-brand p { margin-top: 14px; font-size: 14px; max-width: 280px; }
.footer-col h3 { font-size: 15px; color: #fff; margin-bottom: 16px; }
.footer-col ul { display: flex; flex-direction: column; gap: 10px; }
.footer-col a { font-size: 14px; color: rgba(226, 243, 253, .7); transition: color .2s ease; }
.footer-col a:hover { color: var(--blue-300); }
.footer-bottom { border-top: 1px solid var(--line-dark); padding: 20px 0; }
.footer-bottom .container { display: flex; flex-wrap: wrap; justify-content: space-between; gap: 8px; }
.footer-bottom p { font-size: 12.5px; color: rgba(226, 243, 253, .5); }

/* ---------- 移动端下载条 / 返回顶部 ---------- */
.mobile-download {
  display: none;
  position: fixed;
  left: 0; right: 0; bottom: 0;
  z-index: 90;
  background: rgba(255, 255, 255, .96);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border-top: 1px solid var(--line);
  box-shadow: 0 -6px 20px -12px rgba(16, 38, 58, .18);
}
.mobile-download-inner {
  max-width: 640px;
  margin: 0 auto;
  padding: 10px 16px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}
.mobile-download strong { display: block; font-size: 15px; color: var(--blue-800); }
.mobile-download span { font-size: 12px; color: var(--ink-3); }

.to-top {
  position: fixed;
  right: 22px; bottom: 22px;
  z-index: 90;
  width: 44px; height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--blue-200);
  border-radius: 50%;
  background: #fff;
  color: var(--blue-600);
  box-shadow: var(--shadow-sm);
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transform: translateY(8px);
  transition: opacity .25s ease, transform .25s ease, visibility .25s ease;
}
.to-top.show { opacity: 1; visibility: visible; transform: translateY(0); }
.to-top:hover { background: var(--blue-50); }
.to-top svg { width: 20px; height: 20px; }

/* ---------- 滚动揭示动效 ---------- */
.reveal { opacity: 0; transform: translateY(18px); transition: opacity .6s ease, transform .6s ease; }
.reveal.in { opacity: 1; transform: none; }

/* ---------- 响应式 ---------- */
@media (max-width: 992px) {
  .hero-inner { grid-template-columns: 1fr; gap: 32px; }
  .hero-copy { padding: 24px 0 0; }
  .hero-phone-wrap { justify-content: center; }
  .hero-phone-wrap::before { right: auto; left: 50%; transform: translateX(-50%); }
  .hero-stats { grid-template-columns: repeat(2, 1fr); gap: 16px; margin-top: 32px; }
  .feature-grid { grid-template-columns: repeat(2, 1fr); }
  .hot-pair { grid-template-columns: 1fr; max-width: 480px; }
  .voices-grid { grid-template-columns: repeat(2, 1fr); }
  .footer-inner { grid-template-columns: 1fr 1fr; gap: 32px; }

  .nav-links {
    position: fixed;
    top: var(--nav-h); left: 0; right: 0;
    flex-direction: column;
    align-items: stretch;
    gap: 4px;
    padding: 14px 4vw 20px;
    background: rgba(243, 250, 255, .98);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--line);
    box-shadow: var(--shadow-md);
    display: none;
  }
  .nav-links.open { display: flex; }
  .nav-link { padding: 12px 14px; }
  .nav-toggle { display: flex; }
  .mobile-download { display: block; }
  body { padding-bottom: 62px; }
  .to-top { bottom: 78px; }
}

@media (max-width: 640px) {
  .section { padding: 64px 0; }
  .hero { padding: calc(var(--nav-h) + 36px) 0 0; }
  .phone-hero { width: 218px; }
  .hero-stats { border-radius: 20px 20px 0 0; }
  .feature-grid { grid-template-columns: 1fr; }
  .voices-grid { grid-template-columns: 1fr; }
  .cta-full { padding: 48px 20px; }
  .footer-inner { grid-template-columns: 1fr; gap: 28px; }
  .footer-bottom .container { flex-direction: column; }
  .btn-lg { padding: 14px 30px; }
  .hero-tags li { padding: 6px 13px; font-size: 13px; }
  .hot-card { aspect-ratio: 4 / 3; }
  /* 移动端触控目标 ≥ 44px */
  .btn { min-height: 44px; }
  .brand { min-height: 44px; align-items: center; }
  .nav-link { min-height: 44px; display: flex; align-items: center; }
}

/* ---------- 无障碍：减少动效 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition-duration: .01ms !important; animation-duration: .01ms !important; }
  .reveal { opacity: 1; transform: none; }
}