/* 91PO视频官网 - 响应式样式 */
:root {
  --bg-primary: #0d0d14;
  --bg-secondary: #161622;
  --bg-card: #1e1e2e;
  --accent: #7c3aed;
  --accent-light: #a78bfa;
  --accent-orange: #f97316;
  --text-primary: #f1f5f9;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  --border: #2d2d3d;
  --gradient: linear-gradient(135deg, #7c3aed 0%, #ec4899 100%);
  --shadow: 0 4px 24px rgba(124, 58, 237, 0.15);
  --radius: 12px;
  --max-width: 1200px;
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

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

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: 1.7;
  min-height: 100vh;
}

a { color: var(--accent-light); text-decoration: none; transition: color 0.2s; }
a:hover { color: #c4b5fd; }

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

.container { max-width: var(--max-width); margin: 0 auto; padding: 0 20px; }

/* Header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(13, 13, 20, 0.95);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 20px;
  max-width: var(--max-width);
  margin: 0 auto;
}

.logo-link { display: flex; align-items: center; gap: 12px; }
.logo-link img { width: 48px; height: 48px; border-radius: 10px; }
.logo-text { font-size: 1.25rem; font-weight: 700; color: var(--text-primary); }
.logo-text span { color: var(--accent-orange); }

.main-nav { display: flex; gap: 28px; align-items: center; }
.main-nav a { color: var(--text-secondary); font-size: 0.95rem; font-weight: 500; }
.main-nav a:hover, .main-nav a.active { color: var(--text-primary); }

.btn-download {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 22px;
  background: var(--gradient);
  color: #fff !important;
  border-radius: 8px;
  font-weight: 600;
  font-size: 0.9rem;
  box-shadow: var(--shadow);
  transition: transform 0.2s, box-shadow 0.2s;
}
.btn-download:hover { transform: translateY(-2px); box-shadow: 0 6px 28px rgba(124, 58, 237, 0.35); color: #fff !important; }

.menu-toggle { display: none; background: none; border: none; color: var(--text-primary); font-size: 1.5rem; cursor: pointer; }

/* Hero */
.hero {
  padding: 60px 0 80px;
  background: radial-gradient(ellipse at 50% 0%, rgba(124, 58, 237, 0.12) 0%, transparent 60%);
}

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

.hero-content h1 {
  font-size: 2.5rem;
  line-height: 1.3;
  margin-bottom: 20px;
  background: linear-gradient(135deg, #fff 0%, #c4b5fd 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-content .subtitle {
  font-size: 1.15rem;
  color: var(--text-secondary);
  margin-bottom: 28px;
}

.hero-badges { display: flex; flex-wrap: wrap; gap: 10px; margin-bottom: 32px; }
.badge {
  padding: 6px 14px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 20px;
  font-size: 0.85rem;
  color: var(--accent-light);
}

.hero-actions { display: flex; gap: 16px; flex-wrap: wrap; }
.btn-primary {
  padding: 14px 32px;
  background: var(--gradient);
  color: #fff;
  border-radius: 10px;
  font-weight: 600;
  font-size: 1rem;
  border: none;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 8px;
}
.btn-secondary {
  padding: 14px 32px;
  background: var(--bg-card);
  color: var(--text-primary);
  border: 1px solid var(--border);
  border-radius: 10px;
  font-weight: 600;
  font-size: 1rem;
}

.hero-phone {
  display: flex;
  justify-content: center;
  gap: 16px;
}
.hero-phone img {
  width: 200px;
  border-radius: 20px;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.5);
  border: 2px solid var(--border);
}

/* Sections */
.section { padding: 70px 0; }
.section-alt { background: var(--bg-secondary); }
.section-title {
  font-size: 1.85rem;
  text-align: center;
  margin-bottom: 12px;
}
.section-desc {
  text-align: center;
  color: var(--text-secondary);
  margin-bottom: 48px;
  max-width: 640px;
  margin-left: auto;
  margin-right: auto;
}

/* Feature Grid */
.feature-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: 28px;
  transition: transform 0.2s, border-color 0.2s;
}
.feature-card:hover { transform: translateY(-4px); border-color: var(--accent); }
.feature-card h3 { font-size: 1.15rem; margin-bottom: 10px; color: var(--accent-light); }
.feature-card p { color: var(--text-secondary); font-size: 0.95rem; }

/* Screenshot Gallery */
.screenshot-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}
.screenshot-item {
  background: var(--bg-card);
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--border);
  transition: transform 0.2s;
}
.screenshot-item:hover { transform: scale(1.03); }
.screenshot-item img { width: 100%; aspect-ratio: 9/16; object-fit: cover; }
.screenshot-item figcaption {
  padding: 12px;
  font-size: 0.85rem;
  color: var(--text-secondary);
  text-align: center;
}

/* Content Article */
.article-content {
  max-width: 900px;
  margin: 0 auto;
}
.article-content h2 {
  font-size: 1.5rem;
  margin: 40px 0 16px;
  color: var(--accent-light);
  padding-bottom: 8px;
  border-bottom: 1px solid var(--border);
}
.article-content h3 { font-size: 1.2rem; margin: 28px 0 12px; }
.article-content p { margin-bottom: 16px; color: var(--text-secondary); text-align: justify; }
.article-content ul, .article-content ol { margin: 16px 0 16px 24px; color: var(--text-secondary); }
.article-content 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: 18px 24px;
  cursor: pointer;
  font-weight: 600;
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary::after { content: "+"; font-size: 1.2rem; color: var(--accent); }
.faq-item[open] summary::after { content: "−"; }
.faq-answer { padding: 0 24px 18px; color: var(--text-secondary); }

/* Download Steps */
.steps-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}
.step-card {
  text-align: center;
  padding: 28px 20px;
  background: var(--bg-card);
  border-radius: var(--radius);
  border: 1px solid var(--border);
}
.step-num {
  width: 48px; height: 48px;
  background: var(--gradient);
  border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  font-size: 1.25rem; font-weight: 700;
  margin: 0 auto 16px;
}
.step-card h4 { margin-bottom: 8px; }
.step-card p { color: var(--text-secondary); font-size: 0.9rem; }

/* Legal Pages */
.legal-page { padding: 60px 0 80px; }
.legal-page h1 { font-size: 2rem; margin-bottom: 8px; }
.legal-page .update-date { color: var(--text-muted); margin-bottom: 32px; font-size: 0.9rem; }
.legal-content h2 { font-size: 1.3rem; margin: 32px 0 12px; color: var(--accent-light); }
.legal-content p, .legal-content li { color: var(--text-secondary); margin-bottom: 12px; }
.legal-content ul { margin-left: 24px; }

/* Error Pages */
.error-page {
  min-height: 70vh;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 40px 20px;
}
.error-code { font-size: 6rem; font-weight: 800; background: var(--gradient); -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text; }
.error-page h1 { font-size: 1.5rem; 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: 56px; border-radius: 12px; margin-bottom: 12px; }
.footer-brand p { color: var(--text-muted); font-size: 0.9rem; line-height: 1.6; }
.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-light); }
.footer-bottom {
  border-top: 1px solid var(--border);
  padding-top: 24px;
  text-align: center;
  color: var(--text-muted);
  font-size: 0.85rem;
}

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

/* Mobile Nav */
@media (max-width: 992px) {
  .hero-grid { grid-template-columns: 1fr; text-align: center; }
  .hero-phone { order: -1; }
  .hero-actions { justify-content: center; }
  .hero-badges { justify-content: center; }
  .feature-grid { grid-template-columns: repeat(2, 1fr); }
  .screenshot-grid { grid-template-columns: repeat(2, 1fr); }
  .steps-grid { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 768px) {
  .menu-toggle { display: block; }
  .main-nav {
    display: none;
    position: absolute;
    top: 100%;
    left: 0; right: 0;
    background: var(--bg-secondary);
    flex-direction: column;
    padding: 20px;
    gap: 16px;
    border-bottom: 1px solid var(--border);
  }
  .main-nav.open { display: flex; }
  .header-inner { position: relative; }
  .hero-content h1 { font-size: 1.75rem; }
  .hero-phone img { width: 140px; }
  .feature-grid { grid-template-columns: 1fr; }
  .screenshot-grid { grid-template-columns: repeat(2, 1fr); gap: 12px; }
  .steps-grid { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; }
  .section { padding: 48px 0; }
  .section-title { font-size: 1.5rem; }
}