/* 抖阴视频官网 - 全局样式 */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --bg-primary: #0d0d12;
  --bg-secondary: #16161f;
  --bg-card: #1e1e2a;
  --accent: #ff2d55;
  --accent-hover: #ff4d6d;
  --text-primary: #f0f0f5;
  --text-secondary: #a0a0b0;
  --text-muted: #6a6a7a;
  --border: #2a2a3a;
  --gradient: linear-gradient(135deg, #ff2d55 0%, #c41e3a 100%);
  --shadow: 0 4px 24px rgba(255, 45, 85, 0.15);
  --radius: 12px;
  --max-width: 1200px;
  --page-gutter: 20px;
}

html { scroll-behavior: smooth; font-size: 16px; overflow-x: hidden; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.8;
  min-height: 100vh;
  overflow-x: hidden;
}

a { color: var(--accent); text-decoration: none; transition: color 0.2s; }
a:hover { color: var(--accent-hover); }

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

.container { max-width: var(--max-width); margin: 0 auto; padding: 0 var(--page-gutter); }

main { display: block; }

/* Header */
.site-header {
  background: rgba(13, 13, 18, 0.95);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 1000;
}

/* Sticky top: header + ads (desktop) */
.site-top {
  position: sticky;
  top: 0;
  z-index: 1000;
}

.site-top .site-header {
  position: static;
  z-index: auto;
}

/* Ads bar */
.ads-bar {
  display: none;
  background: rgba(22, 22, 31, 0.98);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  padding: 8px 12px;
}
.ads-bar--visible { display: block; }

.ads-bar #ads {
  display: flex;
  justify-content: center;
  align-items: flex-start;
  flex-wrap: wrap;
  gap: 4px 8px;
  background: transparent;
  max-width: var(--max-width);
  margin: 0 auto;
}

.ads-bar #ads > div {
  display: flex;
  flex-direction: column;
  align-items: center;
  width: 72px;
  box-sizing: border-box;
}

.ads-bar #ads img {
  width: 58px;
  height: 58px;
  object-fit: cover;
  border-radius: 14px;
  box-shadow: 0 4px 14px rgba(0, 0, 0, 0.35);
  transition: transform 180ms ease, box-shadow 180ms ease;
  display: block;
  border: 1px solid var(--border);
  background: var(--bg-card);
}

.ads-bar #ads a {
  display: inline-block;
  text-decoration: none;
  border-radius: 14px;
}

.ads-bar #ads img:hover {
  transform: translateY(-3px) scale(1.05);
  box-shadow: 0 8px 20px rgba(255, 45, 85, 0.25);
}

.ads-bar #ads .caption {
  margin-top: 4px;
  height: 15px;
  font-size: 11px;
  color: var(--text-muted);
  text-align: center;
  max-width: 72px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px var(--page-gutter);
  max-width: var(--max-width);
  margin: 0 auto;
  position: relative;
}

.logo-link { display: flex; align-items: center; gap: 12px; flex-shrink: 0; min-width: 0; }
.logo-link img { width: 42px; height: 42px; border-radius: 8px; flex-shrink: 0; }
.logo-text { font-size: 1.35rem; font-weight: 700; color: var(--text-primary); white-space: nowrap; }
.logo-text span { color: var(--accent); }

.main-nav { display: flex; gap: 8px; list-style: none; align-items: center; }
.main-nav li { list-style: none; }
.main-nav a {
  color: var(--text-secondary);
  padding: 8px 16px;
  border-radius: 8px;
  font-size: 0.95rem;
  font-weight: 500;
  white-space: nowrap;
}
.main-nav a:hover, .main-nav a.active {
  color: var(--text-primary);
  background: var(--bg-card);
}

.nav-toggle {
  display: none;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 8px;
  color: var(--text-primary);
  font-size: 1.25rem;
  line-height: 1;
  cursor: pointer;
  width: 44px;
  height: 44px;
  flex-shrink: 0;
  align-items: center;
  justify-content: center;
}

/* Hero */
.hero {
  padding: 60px 0 50px;
  background: radial-gradient(ellipse at 50% 0%, rgba(255, 45, 85, 0.12) 0%, transparent 60%);
}

.hero-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  align-items: center;
}

.hero h1 {
  font-size: 2.4rem;
  line-height: 1.3;
  margin-bottom: 20px;
  background: linear-gradient(135deg, #fff 0%, #ff8fa3 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-desc { color: var(--text-secondary); font-size: 1.1rem; margin-bottom: 28px; }

.btn-group { display: flex; gap: 16px; flex-wrap: wrap; }

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 32px;
  border-radius: 50px;
  font-size: 1rem;
  font-weight: 600;
  border: none;
  cursor: pointer;
  transition: transform 0.2s, box-shadow 0.2s;
}

.btn-primary {
  background: var(--gradient);
  color: #fff;
  box-shadow: var(--shadow);
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 6px 30px rgba(255, 45, 85, 0.3); color: #fff; }

.btn-outline {
  background: transparent;
  color: var(--text-primary);
  border: 2px solid var(--border);
}
.btn-outline:hover { border-color: var(--accent); color: var(--accent); }

.hero-image {
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.5);
  border: 1px solid var(--border);
}

/* Sections */
.section { padding: 60px 0; }
.section-alt { background: var(--bg-secondary); }

.section-header { text-align: center; margin-bottom: 48px; }
.section-header h2 { font-size: 1.9rem; margin-bottom: 12px; }
.section-header p { color: var(--text-secondary); max-width: 600px; margin: 0 auto; }

/* Feature Cards */
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.feature-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px 24px;
  transition: transform 0.2s, border-color 0.2s;
}
.feature-card:hover { transform: translateY(-4px); border-color: var(--accent); }

.feature-icon {
  width: 52px; height: 52px;
  background: rgba(255, 45, 85, 0.12);
  border-radius: 12px;
  display: flex; align-items: center; justify-content: center;
  font-size: 1.5rem;
  margin-bottom: 16px;
}

.feature-card h3 { font-size: 1.15rem; margin-bottom: 10px; }
.feature-card p { color: var(--text-secondary); font-size: 0.95rem; }

/* Category Grid */
.category-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

.category-card {
  background: var(--bg-card);
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--border);
  transition: transform 0.2s;
}
.category-card:hover { transform: scale(1.03); }

.category-card img { width: 100%; aspect-ratio: 9/16; object-fit: cover; }
.category-card .cat-label {
  padding: 12px 16px;
  font-weight: 600;
  font-size: 0.95rem;
  text-align: center;
}

/* Screenshot Gallery */
.screenshot-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.screenshot-item {
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--border);
  background: var(--bg-card);
}

.screenshot-item img { width: 100%; }
.screenshot-item figcaption {
  padding: 14px 16px;
  font-size: 0.9rem;
  color: var(--text-secondary);
  text-align: center;
}

/* Content Article */
.content-article { max-width: 900px; margin: 0 auto; }
.content-article h2 { font-size: 1.6rem; margin: 40px 0 16px; color: var(--text-primary); }
.content-article h3 { font-size: 1.25rem; margin: 28px 0 12px; color: var(--text-primary); }
.content-article p { color: var(--text-secondary); margin-bottom: 16px; text-align: justify; }
.content-article ul, .content-article ol { color: var(--text-secondary); margin: 12px 0 16px 24px; }
.content-article li { margin-bottom: 8px; }

/* FAQ */
.faq-list { max-width: 800px; margin: 0 auto; }
.faq-item {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  margin-bottom: 16px;
  overflow: hidden;
}
.faq-item summary {
  padding: 20px 24px;
  font-weight: 600;
  cursor: pointer;
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.faq-item summary::after { content: "+"; font-size: 1.3rem; color: var(--accent); }
.faq-item[open] summary::after { content: "−"; }
.faq-item .faq-answer { padding: 0 24px 20px; color: var(--text-secondary); }

/* Download Steps */
.steps-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  counter-reset: step;
}

.step-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px 20px;
  text-align: center;
  position: relative;
}

.step-card::before {
  counter-increment: step;
  content: counter(step);
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px; height: 40px;
  background: var(--gradient);
  border-radius: 50%;
  font-weight: 700;
  margin: 0 auto 16px;
}

.step-card h3 { font-size: 1rem; margin-bottom: 8px; }
.step-card p { color: var(--text-secondary); font-size: 0.9rem; }

/* Breadcrumb */
.breadcrumb {
  padding: 16px 0;
  font-size: 0.9rem;
  color: var(--text-muted);
}
.breadcrumb a { color: var(--text-secondary); }
.breadcrumb span { margin: 0 8px; }

/* Legal Pages */
.legal-content { max-width: 860px; margin: 0 auto; padding: 40px 0 60px; }
.legal-content h1 { font-size: 2rem; margin-bottom: 8px; }
.legal-content .update-date { color: var(--text-muted); font-size: 0.9rem; margin-bottom: 32px; }
.legal-content h2 { font-size: 1.3rem; margin: 32px 0 12px; }
.legal-content p, .legal-content li { color: var(--text-secondary); margin-bottom: 12px; }
.legal-content ul, .legal-content ol { margin-left: 24px; margin-bottom: 16px; }

/* Error Pages */
.error-page {
  min-height: 70vh;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 40px var(--page-gutter);
}
.error-code { font-size: 6rem; font-weight: 800; color: var(--accent); line-height: 1; }
.error-page h1 { font-size: 1.8rem; margin: 16px 0; }
.error-page p { color: var(--text-secondary); margin-bottom: 28px; }

/* Footer */
.site-footer {
  background: var(--bg-secondary);
  border-top: 1px solid var(--border);
  padding: 48px 0 24px;
  margin-top: 40px;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 40px;
  margin-bottom: 40px;
}

.footer-brand img { width: 48px; margin-bottom: 12px; border-radius: 8px; }
.footer-brand p { color: var(--text-muted); font-size: 0.9rem; max-width: 280px; }

.footer-col h4 { font-size: 0.95rem; margin-bottom: 16px; color: var(--text-primary); }
.footer-col ul { list-style: none; }
.footer-col li { margin-bottom: 10px; }
.footer-col a { color: var(--text-muted); font-size: 0.9rem; }
.footer-col a:hover { color: var(--accent); }

.footer-bottom {
  border-top: 1px solid var(--border);
  padding-top: 24px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 12px;
}
.footer-bottom p { color: var(--text-muted); font-size: 0.85rem; }

/* Internal links highlight */
.internal-links {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px 28px;
  margin: 32px 0;
}
.internal-links h3 { font-size: 1.1rem; margin-bottom: 12px; }
.internal-links ul { list-style: none; display: flex; flex-wrap: wrap; gap: 12px 24px; }
.internal-links a { font-size: 0.95rem; }

/* Responsive */
@media (max-width: 992px) {
  :root {
    --page-gutter: 16px;
  }

  .container,
  .header-inner,
  .error-page {
    padding-left: max(var(--page-gutter), env(safe-area-inset-left, 0px));
    padding-right: max(var(--page-gutter), env(safe-area-inset-right, 0px));
  }

  .site-header {
    position: static;
  }

  .hero-grid { grid-template-columns: 1fr; gap: 32px; }
  .hero-image { max-width: 360px; margin: 0 auto; }
  .features-grid { grid-template-columns: repeat(2, 1fr); }
  .category-grid { grid-template-columns: repeat(3, 1fr); }
  .screenshot-grid { grid-template-columns: repeat(2, 1fr); }
  .steps-grid { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: repeat(2, 1fr); }

  .header-inner { flex-wrap: wrap; padding: 10px var(--page-gutter); }
  .logo-link { flex: 1; }
  .nav-toggle { display: flex; }
  .header-inner > nav { width: 100%; order: 3; }
  .main-nav {
    display: none;
    flex-direction: column;
    align-items: stretch;
    width: 100%;
    gap: 4px;
    padding: 10px 0 4px;
    margin-top: 10px;
    border-top: 1px solid var(--border);
  }
  .main-nav.open { display: flex; }
  .main-nav a { display: block; padding: 12px 16px; white-space: normal; }
  .site-header { border-bottom: none; }
  .site-top .site-header { border-bottom: none; }

  /* 移动端：导航 + 广告固定顶部 */
  .site-top {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    width: 100%;
    z-index: 1000;
    background: rgba(13, 13, 18, 0.98);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    box-shadow: 0 2px 16px rgba(0, 0, 0, 0.35);
  }

  .site-top .site-header {
    background: transparent;
    border-bottom: none;
  }

  .site-top .ads-bar {
    border-top: 1px solid var(--border);
  }

  body:not(:has(.site-top)) .site-header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    width: 100%;
    z-index: 1000;
    background: rgba(13, 13, 18, 0.98);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    box-shadow: 0 2px 16px rgba(0, 0, 0, 0.35);
  }
}

@media (max-width: 768px) {
  .logo-text { font-size: 1.15rem; }
  .logo-link img { width: 36px; height: 36px; }

  .ads-bar {
    padding-top: 6px;
    padding-bottom: 6px;
    padding-left: max(var(--page-gutter), env(safe-area-inset-left, 0px));
    padding-right: max(var(--page-gutter), env(safe-area-inset-right, 0px));
  }
  .ads-bar #ads { gap: 2px 6px; justify-content: flex-start; overflow-x: auto; flex-wrap: nowrap; -webkit-overflow-scrolling: touch; scrollbar-width: none; }
  .ads-bar #ads::-webkit-scrollbar { display: none; }
  .ads-bar #ads > div { width: 64px; flex-shrink: 0; }
  .ads-bar #ads img { width: 52px; height: 52px; }
  .ads-bar #ads .caption { max-width: 64px; font-size: 10px; }

  .hero { padding: 28px 0 36px; }
  .hero h1 { font-size: 1.65rem; }
  .hero-desc { font-size: 1rem; margin-bottom: 20px; }

  .btn-group { flex-direction: column; }
  .btn { width: 100%; justify-content: center; padding: 13px 24px; font-size: 0.95rem; }

  .section { padding: 40px 0; }
  .section-header { margin-bottom: 32px; }
  .section-header h2 { font-size: 1.45rem; }
  .section-header p { font-size: 0.95rem; }

  .features-grid { grid-template-columns: 1fr; gap: 16px; }
  .feature-card { padding: 24px 20px; }

  .category-grid { grid-template-columns: repeat(2, 1fr); gap: 12px; }
  .category-card .cat-label { padding: 10px 8px; font-size: 0.85rem; }

  .screenshot-grid { grid-template-columns: 1fr; gap: 16px; }
  .steps-grid { grid-template-columns: 1fr; gap: 16px; }
  .footer-grid { grid-template-columns: 1fr; gap: 28px; }

  .content-article h2 { font-size: 1.35rem; margin-top: 32px; }
  .content-article h3 { font-size: 1.1rem; }
  .content-article p { text-align: left; }

  .faq-item summary { padding: 16px 18px; font-size: 0.95rem; }
  .faq-item .faq-answer { padding: 0 18px 16px; font-size: 0.9rem; }

  .legal-content { padding: 24px 0 40px; }
  .legal-content h1 { font-size: 1.6rem; }
  .legal-content h2 { font-size: 1.15rem; }

  .breadcrumb { padding-left: 0; padding-right: 0; }

  .internal-links { padding: 18px 16px; }
  .internal-links ul { flex-direction: column; gap: 10px; }

  .error-code { font-size: 4.5rem; }
  .error-page h1 { font-size: 1.4rem; }
  .error-page { min-height: 50vh; padding: 32px var(--page-gutter); }

  .footer-bottom { flex-direction: column; text-align: center; }
  .site-footer { padding: 36px 0 20px; }
}

@media (max-width: 480px) {
  :root {
    --page-gutter: 14px;
  }

  .hero h1 { font-size: 1.45rem; }
}