:root {
  --bg: #f8faf8;
  --panel: #ffffff;
  --ink: #17211d;
  --muted: #68766e;
  --line: rgba(23, 33, 29, .10);
  --soft: #edf4ee;
  --accent: #36564c;
  --accent-2: #8fb69d;
  --gold: #c7aa76;
  --radius-lg: 34px;
  --radius-md: 24px;
  --shadow: 0 24px 70px rgba(23, 33, 29, .08);
  --shadow-soft: 0 16px 40px rgba(23, 33, 29, .06);
  font-synthesis-weight: none;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--ink);
  background: radial-gradient(circle at top left, rgba(143, 182, 157, .28), transparent 34rem), var(--bg);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", Arial, sans-serif;
  line-height: 1.75;
  text-rendering: optimizeLegibility;
}
a { color: inherit; text-decoration: none; }
img { max-width: 100%; height: auto; display: block; }
button, input, textarea { font: inherit; }
.container { width: min(1120px, calc(100% - 40px)); margin: 0 auto; }
.narrow { width: min(880px, calc(100% - 40px)); }
.sr-only { position: absolute; width: 1px; height: 1px; clip: rect(0, 0, 0, 0); overflow: hidden; white-space: nowrap; }
.site-header {
  position: sticky; top: 0; z-index: 20;
  backdrop-filter: blur(18px);
  background: rgba(248, 250, 248, .88);
  border-bottom: 1px solid var(--line);
}
.nav-wrap { min-height: 76px; display: flex; align-items: center; justify-content: space-between; gap: 24px; }
.brand-link { display: inline-flex; align-items: center; }
.top-nav { display: flex; align-items: center; gap: 4px; }
.top-nav a {
  padding: 10px 14px; border-radius: 999px; color: var(--muted); font-size: 14px;
  transition: color .2s ease, background .2s ease, transform .2s ease;
}
.top-nav a:hover, .top-nav a.active { color: var(--ink); background: rgba(54, 86, 76, .08); transform: translateY(-1px); }
.menu-toggle { display: none; border: 1px solid var(--line); background: var(--panel); border-radius: 999px; padding: 9px 14px; color: var(--accent); }
.search-row {
  display: grid; grid-template-columns: 1fr auto; gap: 12px; align-items: center;
  padding-bottom: 18px;
}
.search-row input {
  width: 100%; border: 1px solid var(--line); background: rgba(255, 255, 255, .82);
  border-radius: 999px; padding: 14px 18px; outline: none; box-shadow: var(--shadow-soft);
}
.search-row input:focus { border-color: rgba(54, 86, 76, .36); box-shadow: 0 0 0 4px rgba(143, 182, 157, .18); }
.search-row button, .btn, .ghost-btn {
  border: 0; border-radius: 999px; padding: 14px 20px; cursor: pointer;
  transition: transform .2s ease, box-shadow .2s ease, background .2s ease;
}
.search-row button, .btn { background: var(--accent); color: #fff; box-shadow: 0 14px 30px rgba(54, 86, 76, .18); }
.ghost-btn { border: 1px solid var(--line); background: rgba(255, 255, 255, .68); color: var(--accent); }
.search-row button:hover, .btn:hover, .ghost-btn:hover { transform: translateY(-2px); box-shadow: var(--shadow-soft); }
.search-hint { grid-column: 1 / -1; margin: -2px 0 0; color: var(--muted); font-size: 13px; }
.hero { padding: 92px 0 72px; }
.hero-grid { display: grid; grid-template-columns: minmax(0, 1.02fr) minmax(360px, .78fr); gap: 58px; align-items: center; }
.eyebrow { margin: 0 0 12px; letter-spacing: .08em; color: var(--accent); font-weight: 700; font-size: 13px; text-transform: uppercase; }
h1, h2, h3 { line-height: 1.18; letter-spacing: -.04em; }
h1 { margin: 0; font-size: clamp(42px, 7vw, 82px); }
h2 { margin: 0 0 14px; font-size: clamp(28px, 4vw, 48px); }
h3 { margin: 0 0 10px; font-size: 21px; }
.lead { margin: 22px 0 0; max-width: 660px; color: var(--muted); font-size: 18px; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 14px; align-items: center; margin-top: 32px; }
.trust-row { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 30px; color: var(--muted); }
.trust-row span { border: 1px solid var(--line); border-radius: 999px; padding: 8px 12px; background: rgba(255,255,255,.54); }
.hero-visual { border-radius: 42px; padding: 18px; background: linear-gradient(145deg, rgba(255,255,255,.92), rgba(237,244,238,.78)); box-shadow: var(--shadow); border: 1px solid rgba(255,255,255,.8); }
.hero-visual figure { margin: 0; position: relative; overflow: hidden; border-radius: 32px; }
.hero-visual figcaption, .video-card figcaption { position: absolute; left: 18px; bottom: 16px; right: 18px; color: rgba(255,255,255,.92); font-size: 13px; text-shadow: 0 2px 10px rgba(0,0,0,.35); }
.section { padding: 72px 0; }
.section-head { display: flex; justify-content: space-between; gap: 24px; align-items: end; margin-bottom: 28px; }
.section-head p { margin: 0; max-width: 620px; color: var(--muted); }
.about-panel, .join-panel, .notice-panel { background: rgba(255,255,255,.76); border: 1px solid var(--line); border-radius: var(--radius-lg); box-shadow: var(--shadow-soft); padding: clamp(28px, 5vw, 56px); }
.about-panel { display: grid; grid-template-columns: 1.1fr .9fr; gap: 36px; align-items: center; }
.about-list { display: grid; gap: 14px; margin: 0; padding: 0; list-style: none; }
.about-list li { padding: 18px; border-radius: 22px; background: rgba(237,244,238,.65); border: 1px solid var(--line); }
.video-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 22px; }
.video-card { background: rgba(255,255,255,.86); border: 1px solid var(--line); border-radius: 30px; box-shadow: var(--shadow-soft); overflow: hidden; transition: transform .24s ease, box-shadow .24s ease, border-color .24s ease; }
.video-card:hover, .video-card:focus-within { transform: translateY(-6px); box-shadow: var(--shadow); border-color: rgba(54,86,76,.18); }
.video-card figure { margin: 0; position: relative; aspect-ratio: 16 / 10; overflow: hidden; background: var(--soft); }
.video-card img { width: 100%; height: 100%; object-fit: cover; transform: scale(1.01); transition: transform .32s ease, filter .32s ease; }
.video-card:hover img { transform: scale(1.055); filter: saturate(1.04) contrast(1.02); }
.play-badge { position: absolute; inset: 50% auto auto 50%; width: 60px; height: 60px; transform: translate(-50%, -50%) scale(.88); border-radius: 999px; display: grid; place-items: center; background: rgba(23, 33, 29, .72); color: #fff; opacity: 0; transition: opacity .24s ease, transform .24s ease; backdrop-filter: blur(8px); }
.video-card:hover .play-badge, .video-card:focus .play-badge { opacity: 1; transform: translate(-50%, -50%) scale(1); }
.video-body { padding: 22px; }
.video-body p { color: var(--muted); margin: 0 0 16px; }
.tag-row { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 14px; }
.tag-row span { font-size: 12px; border: 1px solid var(--line); color: var(--accent); background: rgba(143,182,157,.12); border-radius: 999px; padding: 5px 9px; }
.metrics { display: flex; gap: 12px; flex-wrap: wrap; color: var(--muted); font-size: 13px; }
.board-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 18px; }
.board-card { padding: 24px; border: 1px solid var(--line); border-radius: 28px; background: rgba(255,255,255,.74); box-shadow: var(--shadow-soft); transition: transform .2s ease, background .2s ease; }
.board-card:hover { transform: translateY(-4px); background: #fff; }
.board-card p { color: var(--muted); margin: 0 0 14px; }
.stats-grid { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 16px; }
.stat { padding: 26px; border-radius: 28px; background: linear-gradient(145deg, #fff, rgba(237,244,238,.8)); border: 1px solid var(--line); }
.stat strong { display: block; font-size: clamp(30px, 5vw, 52px); letter-spacing: -.05em; }
.stat span { color: var(--muted); }
.review-grid { display: grid; grid-template-columns: repeat(3, minmax(0,1fr)); gap: 18px; }
.review { padding: 24px; border-radius: 28px; border: 1px solid var(--line); background: rgba(255,255,255,.82); box-shadow: var(--shadow-soft); }
.review p { color: var(--muted); }
.review strong { display: block; }
.faq-list { display: grid; gap: 12px; }
details { border: 1px solid var(--line); border-radius: 24px; background: rgba(255,255,255,.82); padding: 18px 20px; }
summary { cursor: pointer; font-weight: 700; }
details p { color: var(--muted); margin-bottom: 0; }
.join-panel { display: grid; grid-template-columns: .9fr 1.1fr; gap: 34px; align-items: start; }
.form-grid { display: grid; gap: 14px; }
.form-grid input, .form-grid textarea { width: 100%; border: 1px solid var(--line); border-radius: 20px; padding: 14px 16px; background: rgba(255,255,255,.84); outline: none; }
.form-grid textarea { min-height: 126px; resize: vertical; }
.social-grid { display: grid; grid-template-columns: repeat(5, minmax(0,1fr)); gap: 12px; }
.social-card { padding: 18px; border: 1px solid var(--line); border-radius: 22px; background: rgba(255,255,255,.78); color: var(--muted); }
.page-hero { padding: 74px 0 46px; text-align: center; }
.page-hero h1 { font-size: clamp(38px, 6vw, 68px); }
.page-hero p { color: var(--muted); max-width: 760px; margin: 18px auto 0; }
.topic-list { display: grid; gap: 14px; }
.topic-row { display: grid; grid-template-columns: 1fr auto; gap: 20px; padding: 20px; background: rgba(255,255,255,.82); border: 1px solid var(--line); border-radius: 26px; box-shadow: var(--shadow-soft); }
.topic-row p { color: var(--muted); margin: 4px 0 12px; }
.side-metric { min-width: 150px; text-align: right; color: var(--muted); font-size: 14px; }
.rank-table { width: 100%; border-collapse: collapse; background: rgba(255,255,255,.82); border-radius: 28px; overflow: hidden; box-shadow: var(--shadow-soft); }
.rank-table th, .rank-table td { padding: 18px; text-align: left; border-bottom: 1px solid var(--line); }
.rank-table th { color: var(--accent); background: rgba(237,244,238,.7); }
.timeline { display: grid; gap: 16px; }
.timeline article { padding: 24px; border: 1px solid var(--line); border-radius: 28px; background: rgba(255,255,255,.8); }
.site-footer { margin-top: 70px; padding: 56px 0 24px; background: #111a17; color: rgba(255,255,255,.76); }
.footer-grid { display: grid; grid-template-columns: 1.2fr .8fr .8fr; gap: 40px; }
.footer-grid h2 { font-size: 16px; color: #fff; margin-bottom: 14px; }
.footer-grid a { display: block; color: rgba(255,255,255,.76); margin: 8px 0; }
.footer-grid p { color: rgba(255,255,255,.64); }
.copyright { display: flex; justify-content: space-between; gap: 18px; border-top: 1px solid rgba(255,255,255,.12); margin-top: 36px; padding-top: 22px; color: rgba(255,255,255,.56); font-size: 13px; }
@media (max-width: 940px) {
  .top-nav { display: none; position: absolute; left: 20px; right: 20px; top: 72px; padding: 14px; border: 1px solid var(--line); border-radius: 24px; background: rgba(255,255,255,.96); box-shadow: var(--shadow); flex-direction: column; align-items: stretch; }
  .top-nav.open { display: flex; }
  .menu-toggle { display: inline-flex; }
  .hero-grid, .about-panel, .join-panel, .footer-grid { grid-template-columns: 1fr; }
  .video-grid, .board-grid, .review-grid { grid-template-columns: repeat(2, minmax(0,1fr)); }
  .stats-grid, .social-grid { grid-template-columns: repeat(2, minmax(0,1fr)); }
}
@media (max-width: 640px) {
  .container { width: min(100% - 28px, 1120px); }
  .search-row { grid-template-columns: 1fr; }
  .hero { padding-top: 54px; }
  .hero-actions, .section-head, .copyright { align-items: stretch; flex-direction: column; }
  .video-grid, .board-grid, .review-grid, .stats-grid, .social-grid { grid-template-columns: 1fr; }
  .topic-row { grid-template-columns: 1fr; }
  .side-metric { text-align: left; }
  .site-header { position: static; }
}