:root {
  --bg: #f8f7f3;
  --surface: #ffffff;
  --ink: #1e2527;
  --muted: #6e7779;
  --line: #e7e2d8;
  --accent: #b48b5b;
  --accent-soft: #efe2d0;
  --shadow: 0 24px 80px rgba(30, 37, 39, 0.08);
  --radius-lg: 32px;
  --radius-md: 22px;
  --radius-sm: 14px;
  --max: 1180px;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "Noto Sans CJK SC", Arial, sans-serif;
  color: var(--ink);
  background: radial-gradient(circle at top left, #ffffff 0, var(--bg) 32rem);
  line-height: 1.72;
}
a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }
button, input, textarea { font: inherit; }
.sr-only { position: absolute; inline-size: 1px; block-size: 1px; overflow: hidden; clip: rect(0,0,0,0); white-space: nowrap; }
.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  background: rgba(248, 247, 243, 0.88);
  backdrop-filter: blur(18px);
  border-bottom: 1px solid rgba(231, 226, 216, 0.8);
}
.nav-shell, .search-shell, .footer-grid, .section, .hero {
  width: min(var(--max), calc(100% - 40px));
  margin: 0 auto;
}
.nav-shell { display: flex; align-items: center; justify-content: space-between; gap: 24px; padding: 18px 0 12px; }
.brand-logo { display: inline-flex; align-items: center; gap: 12px; font-weight: 800; letter-spacing: -0.02em; }
.brand-mark { display: grid; place-items: center; width: 42px; height: 42px; border-radius: 50%; color: #fff; background: var(--ink); box-shadow: inset 0 0 0 5px rgba(255,255,255,0.08); }
.brand-name { font-size: 18px; }
.site-nav { display: flex; gap: 4px; align-items: center; flex-wrap: wrap; justify-content: flex-end; }
.site-nav a, .footer-links a { color: var(--muted); padding: 9px 12px; border-radius: 999px; font-size: 14px; transition: color .2s ease, background .2s ease, transform .2s ease; }
.site-nav a:hover, .site-nav a.is-active, .footer-links a:hover { color: var(--ink); background: var(--surface); transform: translateY(-1px); }
.nav-toggle { display: none; border: 0; background: var(--surface); border-radius: 12px; padding: 8px 11px; }
.search-shell { padding: 0 0 16px; }
.search-form { display: grid; grid-template-columns: 1fr auto; gap: 10px; background: var(--surface); padding: 8px; border: 1px solid var(--line); border-radius: 999px; box-shadow: 0 10px 30px rgba(30,37,39,0.04); }
.search-form input { border: 0; outline: 0; background: transparent; padding: 11px 16px; min-width: 0; }
.search-form button, .btn, .ghost-btn { border: 1px solid var(--ink); background: var(--ink); color: #fff; padding: 11px 18px; border-radius: 999px; cursor: pointer; transition: transform .2s ease, box-shadow .2s ease, background .2s ease; }
.search-form button:hover, .btn:hover, .ghost-btn:hover { transform: translateY(-2px); box-shadow: 0 14px 30px rgba(30,37,39,0.14); }
.ghost-btn { background: transparent; color: var(--ink); border-color: var(--line); }
.search-note { margin: 8px 16px 0; color: var(--muted); font-size: 13px; }
.hero { min-height: 78vh; display: grid; grid-template-columns: minmax(0, 1fr) minmax(320px, 0.9fr); align-items: center; gap: 52px; padding: 78px 0 84px; }
.eyebrow { color: var(--accent); font-size: 13px; letter-spacing: 0.14em; text-transform: uppercase; font-weight: 700; margin: 0 0 14px; }
h1, h2, h3 { line-height: 1.16; letter-spacing: -0.035em; margin: 0; }
h1 { font-size: clamp(42px, 7vw, 82px); max-width: 860px; }
h2 { font-size: clamp(30px, 4.5vw, 54px); }
h3 { font-size: 22px; }
p { margin: 0; }
.hero-copy > p:not(.eyebrow) { margin-top: 22px; color: var(--muted); font-size: 18px; max-width: 690px; }
.hero-actions { display: flex; gap: 12px; flex-wrap: wrap; margin-top: 36px; }
.hero-card { position: relative; border-radius: var(--radius-lg); overflow: hidden; background: var(--surface); box-shadow: var(--shadow); }
.hero-card img { aspect-ratio: 16 / 11; object-fit: cover; }
.hero-float { position: absolute; left: 24px; right: 24px; bottom: 24px; padding: 20px; border: 1px solid rgba(255,255,255,0.55); border-radius: 24px; background: rgba(255,255,255,0.78); backdrop-filter: blur(16px); }
.hero-float strong { display: block; font-size: 20px; }
.hero-float span { color: var(--muted); }
.section { padding: 84px 0; }
.section-head { display: flex; align-items: end; justify-content: space-between; gap: 24px; margin-bottom: 32px; }
.section-head p { color: var(--muted); max-width: 520px; }
.grid { display: grid; gap: 18px; }
.grid-2 { grid-template-columns: repeat(2, minmax(0,1fr)); }
.grid-3 { grid-template-columns: repeat(3, minmax(0,1fr)); }
.grid-4 { grid-template-columns: repeat(4, minmax(0,1fr)); }
.card, .case-card, .testimonial, .faq-item, .contact-card { background: rgba(255,255,255,0.78); border: 1px solid var(--line); border-radius: var(--radius-md); padding: 28px; box-shadow: 0 18px 60px rgba(30,37,39,0.045); }
.card p, .case-card p, .testimonial p, .contact-card p, .article p, .video-body p { color: var(--muted); }
.brand-intro { display: grid; grid-template-columns: 0.88fr 1.12fr; gap: 36px; align-items: center; }
.brand-intro figure { margin: 0; border-radius: var(--radius-lg); overflow: hidden; box-shadow: var(--shadow); background: var(--surface); }
.brand-intro figcaption, .image-description { color: var(--muted); font-size: 13px; padding-top: 12px; }
.video-grid { grid-template-columns: repeat(3, minmax(0,1fr)); }
.video-card { overflow: hidden; border-radius: var(--radius-lg); border: 1px solid var(--line); background: var(--surface); box-shadow: var(--shadow); transition: transform .22s ease, box-shadow .22s ease; }
.video-card:hover, .video-card.is-hovered { transform: translateY(-6px); box-shadow: 0 28px 90px rgba(30,37,39,0.12); }
.video-cover { position: relative; display: block; overflow: hidden; background: var(--accent-soft); }
.video-cover img { width: 100%; aspect-ratio: 16 / 10; object-fit: cover; transition: transform .35s ease, filter .35s ease; }
.video-card:hover .video-cover img, .video-card.is-hovered .video-cover img { transform: scale(1.035); filter: saturate(1.04); }
.play-button { position: absolute; left: 50%; top: 50%; transform: translate(-50%,-50%) scale(.86); display: grid; place-items: center; width: 64px; height: 64px; border-radius: 50%; color: #fff; background: rgba(30,37,39,0.88); opacity: 0; transition: opacity .2s ease, transform .2s ease; }
.video-card:hover .play-button, .video-card.is-hovered .play-button, .video-cover:focus .play-button { opacity: 1; transform: translate(-50%,-50%) scale(1); }
.video-duration { position: absolute; right: 14px; bottom: 14px; padding: 3px 9px; color: #fff; border-radius: 999px; background: rgba(30,37,39,0.76); font-size: 12px; }
.video-body { padding: 22px; }
.video-body h3 { margin-bottom: 10px; }
.tags { display: flex; gap: 8px; flex-wrap: wrap; margin: 16px 0; }
.tags span { background: var(--accent-soft); color: #765c3d; border-radius: 999px; padding: 5px 10px; font-size: 12px; }
.metrics { display: flex; gap: 12px; flex-wrap: wrap; list-style: none; padding: 0; margin: 0; color: var(--muted); font-size: 13px; }
.stats { display: grid; grid-template-columns: repeat(4, minmax(0,1fr)); gap: 14px; }
.stat { border-radius: var(--radius-md); padding: 28px; background: var(--ink); color: #fff; }
.stat strong { display: block; font-size: clamp(30px, 4vw, 46px); line-height: 1; }
.stat span { color: rgba(255,255,255,0.72); }
.case-card strong { color: var(--accent); font-size: 32px; display: block; margin-bottom: 16px; }
.faq-list { display: grid; gap: 12px; }
.faq-item summary { cursor: pointer; font-weight: 700; list-style: none; }
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item p { margin-top: 14px; color: var(--muted); }
.testimonial { display: grid; gap: 12px; }
.testimonial span { color: var(--muted); font-size: 13px; }
.contact-layout { display: grid; grid-template-columns: .8fr 1.2fr; gap: 22px; align-items: start; }
.contact-form { display: grid; gap: 12px; }
.contact-form input, .contact-form textarea { width: 100%; border: 1px solid var(--line); background: var(--surface); border-radius: 16px; padding: 14px 16px; outline: 0; }
.contact-form textarea { min-height: 132px; resize: vertical; }
.page-hero { padding: 76px 0 48px; }
.breadcrumb { color: var(--muted); font-size: 14px; margin-bottom: 18px; }
.article { max-width: 860px; }
.article h2 { margin-top: 44px; margin-bottom: 16px; font-size: clamp(26px, 3.4vw, 42px); }
.article p + p { margin-top: 16px; }
.article ul { color: var(--muted); }
.social-grid button { border: 1px solid var(--line); border-radius: 18px; padding: 18px; background: var(--surface); cursor: pointer; text-align: left; transition: transform .2s ease, box-shadow .2s ease; }
.social-grid button:hover { transform: translateY(-3px); box-shadow: var(--shadow); }
.site-footer { margin-top: 70px; padding: 64px 0 28px; background: #202729; color: #fff; }
.footer-grid { display: grid; grid-template-columns: 1.2fr .8fr .9fr; gap: 36px; }
.footer-grid p, .footer-links a, .copyright { color: rgba(255,255,255,0.68); }
.footer-logo .brand-mark { background: #fff; color: var(--ink); }
.footer-links { display: grid; gap: 6px; align-content: start; }
.footer-links a { padding-left: 0; }
.footer-contact h2 { font-size: 22px; margin-bottom: 14px; }
.copyright { width: min(var(--max), calc(100% - 40px)); margin: 42px auto 0; padding-top: 22px; border-top: 1px solid rgba(255,255,255,0.12); font-size: 13px; }
.toast { position: fixed; left: 50%; bottom: 24px; transform: translateX(-50%) translateY(20px); opacity: 0; pointer-events: none; z-index: 50; background: var(--ink); color: #fff; border-radius: 999px; padding: 12px 18px; box-shadow: var(--shadow); transition: opacity .2s ease, transform .2s ease; }
.toast.is-visible { opacity: 1; transform: translateX(-50%) translateY(0); }
@media (max-width: 980px) {
  .hero, .brand-intro, .contact-layout, .footer-grid { grid-template-columns: 1fr; }
  .video-grid, .grid-3, .grid-4, .stats { grid-template-columns: repeat(2, minmax(0,1fr)); }
  .site-nav { display: none; width: 100%; }
  .site-nav.is-open { display: grid; grid-template-columns: 1fr 1fr; }
  .nav-shell { flex-wrap: wrap; }
  .nav-toggle { display: inline-block; }
}
@media (max-width: 640px) {
  .nav-shell, .search-shell, .footer-grid, .section, .hero { width: min(100% - 24px, var(--max)); }
  .hero { min-height: auto; padding: 52px 0; }
  .section { padding: 56px 0; }
  .search-form { grid-template-columns: 1fr; border-radius: 24px; }
  .search-form button { width: 100%; }
  .video-grid, .grid-2, .grid-3, .grid-4, .stats { grid-template-columns: 1fr; }
  .section-head { display: grid; }
  h1 { font-size: 42px; }
  .site-nav.is-open { grid-template-columns: 1fr; }
}