:root {
  --bg: #f6f4ef;
  --paper: #ffffff;
  --ink: #17202a;
  --muted: #5f6b7a;
  --line: #e5e0d7;
  --accent: #8a6f3e;
  --accent-strong: #5c4724;
  --soft: #ede6d8;
  --shadow: 0 18px 45px rgba(23, 32, 42, 0.08);
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  color: var(--ink);
  background: var(--bg);
  line-height: 1.7;
}
a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(246, 244, 239, 0.95);
  backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--line);
}
.header-inner {
  max-width: 1180px;
  margin: 0 auto;
  padding: 14px 20px;
  display: flex;
  align-items: center;
  gap: 22px;
}
.brand-logo { display: inline-flex; align-items: center; gap: 10px; min-width: 160px; }
.brand-logo img { width: 44px; height: 44px; border-radius: 14px; box-shadow: var(--shadow); }
.brand-logo strong { display: block; font-size: 20px; line-height: 1.1; }
.brand-logo em { display: block; font-style: normal; color: var(--muted); font-size: 12px; }
.main-nav { display: flex; align-items: center; justify-content: center; gap: 4px; flex: 1; flex-wrap: wrap; }
.main-nav a { padding: 8px 10px; border-radius: 999px; color: var(--muted); font-size: 14px; }
.main-nav a:hover { background: var(--soft); color: var(--ink); }
.header-cta, .primary-btn, .secondary-btn, .footer-cta, .share-action, .search-bar button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border: 0;
  border-radius: 999px;
  padding: 12px 18px;
  font-weight: 700;
  cursor: pointer;
  transition: transform .2s ease, box-shadow .2s ease, background .2s ease;
}
.header-cta, .primary-btn, .footer-cta, .search-bar button { background: var(--ink); color: #fff; box-shadow: var(--shadow); }
.secondary-btn, .share-action { background: var(--soft); color: var(--accent-strong); }
.header-cta:hover, .primary-btn:hover, .secondary-btn:hover, .footer-cta:hover, .share-action:hover, .search-bar button:hover { transform: translateY(-2px); }
.search-bar { max-width: 1180px; margin: 0 auto; padding: 0 20px 14px; display: flex; align-items: center; gap: 14px; }
.search-bar form { flex: 1; display: flex; gap: 10px; }
.search-bar input { flex: 1; border: 1px solid var(--line); border-radius: 999px; padding: 12px 16px; background: #fff; font-size: 15px; }
.search-bar p { margin: 0; color: var(--muted); font-size: 13px; }
.section { max-width: 1180px; margin: 0 auto; padding: 72px 20px; }
.section.alt { max-width: none; padding-left: calc((100vw - min(1180px, 100vw)) / 2 + 20px); padding-right: calc((100vw - min(1180px, 100vw)) / 2 + 20px); background: rgba(255,255,255,.48); }
.hero, .page-hero { display: grid; grid-template-columns: 1.05fr .95fr; gap: 40px; align-items: center; }
.eyebrow { margin: 0 0 12px; color: var(--accent); font-weight: 800; letter-spacing: .08em; text-transform: uppercase; }
h1, h2, h3 { line-height: 1.24; margin: 0 0 14px; }
h1 { font-size: clamp(34px, 5vw, 62px); letter-spacing: -0.04em; }
h2 { font-size: clamp(26px, 3vw, 40px); letter-spacing: -0.03em; }
h3 { font-size: 20px; }
.lead { font-size: 18px; color: var(--muted); margin: 0 0 24px; }
.hero-actions { display: flex; gap: 14px; flex-wrap: wrap; margin-bottom: 20px; }
.hero-points { list-style: none; padding: 0; margin: 0; display: grid; gap: 8px; color: var(--muted); }
.hero-points li::before { content: "✓"; margin-right: 8px; color: var(--accent); font-weight: 900; }
.hero-media, .page-hero figure, .case-panel figure { margin: 0; background: var(--paper); padding: 12px; border-radius: 32px; box-shadow: var(--shadow); border: 1px solid var(--line); }
.hero-media img, .page-hero img, .case-panel img { border-radius: 24px; aspect-ratio: 4 / 3; object-fit: cover; width: 100%; }
figcaption { color: var(--muted); font-size: 13px; padding: 10px 4px 0; }
.section-heading { max-width: 760px; margin-bottom: 28px; }
.section-heading p:last-child { color: var(--muted); margin-bottom: 0; }
.cards, .scenario-grid, .article-grid, .video-grid { display: grid; gap: 18px; }
.four-col { grid-template-columns: repeat(4, minmax(0, 1fr)); }
.three-col { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.scenario-grid, .article-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.card, .scenario-grid article, .article-card, .timeline article, .share-box, .contact-copy {
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 26px;
  padding: 24px;
  box-shadow: var(--shadow);
}
.card p, .scenario-grid p, .article-card p, .timeline p { color: var(--muted); margin-bottom: 0; }
.card-icon { display: inline-flex; padding: 8px 12px; border-radius: 999px; background: var(--soft); color: var(--accent-strong); margin-bottom: 14px; font-weight: 800; }
.metric { color: var(--accent-strong) !important; font-weight: 800; }
.tags { display: flex; gap: 8px; flex-wrap: wrap; margin-top: 14px; }
.tags span { border: 1px solid var(--line); color: var(--muted); border-radius: 999px; padding: 4px 10px; font-size: 12px; background: #fff; }
.video-grid { grid-template-columns: repeat(4, minmax(0, 1fr)); }
.video-grid.compact { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.video-card { background: var(--paper); border: 1px solid var(--line); border-radius: 28px; overflow: hidden; box-shadow: var(--shadow); }
.video-thumb { position: relative; overflow: hidden; background: #ddd; }
.video-thumb img { width: 100%; aspect-ratio: 16 / 10; object-fit: cover; transition: transform .35s ease, filter .35s ease; }
.play-button { position: absolute; inset: 50% auto auto 50%; transform: translate(-50%, -50%) scale(.9); width: 62px; height: 62px; border-radius: 50%; border: 0; background: rgba(23,32,42,.88); color: #fff; font-size: 24px; opacity: 0; transition: opacity .2s ease, transform .2s ease; cursor: pointer; }
.duration { position: absolute; right: 12px; bottom: 12px; border-radius: 999px; background: rgba(0,0,0,.72); color: #fff; padding: 3px 9px; font-size: 12px; }
.video-card:hover .play-button, .video-card:focus-within .play-button { opacity: 1; transform: translate(-50%, -50%) scale(1); }
.video-card:hover img { transform: scale(1.05); filter: brightness(.82); }
.video-body { padding: 18px; }
.video-body p { color: var(--muted); }
.video-stats { display: flex; flex-wrap: wrap; gap: 10px; color: var(--accent-strong); font-weight: 700; font-size: 13px; }
.case-panel { display: grid; grid-template-columns: .9fr 1.1fr; gap: 24px; align-items: center; }
.case-list { display: grid; gap: 16px; }
.case-list article { background: var(--paper); border: 1px solid var(--line); border-radius: 22px; padding: 20px; }
.case-list p { color: var(--muted); margin-bottom: 0; }
.timeline { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 18px; }
.timeline span { display: inline-flex; margin-bottom: 10px; color: var(--accent); font-weight: 900; }
.timeline small { display: block; color: var(--muted); margin-top: 12px; }
.faq-list { display: grid; gap: 12px; }
details { background: var(--paper); border: 1px solid var(--line); border-radius: 20px; padding: 18px 20px; box-shadow: var(--shadow); }
summary { cursor: pointer; font-weight: 800; }
details p { color: var(--muted); margin-bottom: 0; }
.review-card .stars { color: var(--accent); letter-spacing: 2px; margin-bottom: 12px; }
.contact-section { display: grid; grid-template-columns: 1fr .8fr; gap: 22px; align-items: stretch; }
.share-box { display: flex; flex-direction: column; gap: 12px; }
.breadcrumb { max-width: 1180px; margin: 28px auto 0; padding: 0 20px; color: var(--muted); font-size: 14px; }
.breadcrumb a { color: var(--accent-strong); font-weight: 700; }
.breadcrumb span { margin: 0 7px; }
.site-footer { background: #151719; color: #fff; margin-top: 40px; }
.footer-grid { max-width: 1180px; margin: 0 auto; padding: 52px 20px; display: grid; grid-template-columns: 1.3fr .7fr 1fr; gap: 28px; }
.footer-logo img { box-shadow: none; }
.site-footer p, .site-footer a, .site-footer li, .copyright { color: rgba(255,255,255,.72); }
.site-footer h2 { font-size: 20px; }
.site-footer ul { padding: 0; list-style: none; display: grid; gap: 8px; }
.copyright { max-width: 1180px; margin: 0 auto; padding: 18px 20px; border-top: 1px solid rgba(255,255,255,.12); font-size: 13px; }
.sr-only { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0,0,0,0); white-space: nowrap; }
@media (max-width: 980px) {
  .header-inner { align-items: flex-start; flex-direction: column; }
  .main-nav { justify-content: flex-start; }
  .hero, .page-hero, .case-panel, .contact-section { grid-template-columns: 1fr; }
  .four-col, .three-col, .video-grid, .timeline { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .footer-grid { grid-template-columns: 1fr; }
}
@media (max-width: 640px) {
  .section { padding: 48px 16px; }
  .section.alt { padding-left: 16px; padding-right: 16px; }
  .search-bar, .search-bar form { flex-direction: column; align-items: stretch; }
  .four-col, .three-col, .video-grid, .video-grid.compact, .scenario-grid, .article-grid, .timeline { grid-template-columns: 1fr; }
  h1 { font-size: 34px; }
  .header-cta { width: 100%; }
}