:root{
  --bg:#f3eee4;
  --paper:#fbf8f2;
  --ink:#16352f;
  --muted:#5d6e68;
  --line:#d5c7b0;
  --accent:#8a5f3c;
  --accent-2:#2d6b6b;
  --shadow:0 18px 40px rgba(33,39,34,.08);
  --serif:"Songti SC","Noto Serif CJK SC","Source Han Serif SC",serif;
  --sans:"PingFang SC","Hiragino Sans GB","Microsoft YaHei",sans-serif;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{
  margin:0;
  color:var(--ink);
  background:
    radial-gradient(circle at top right, rgba(138,95,60,.16), transparent 24%),
    linear-gradient(180deg, #f8f4eb 0%, var(--bg) 100%);
  font-family:var(--sans);
  line-height:1.72;
}
body::before{
  content:"";
  position:fixed;
  inset:0;
  background-image:linear-gradient(rgba(22,53,47,.03) 1px, transparent 1px), linear-gradient(90deg, rgba(22,53,47,.03) 1px, transparent 1px);
  background-size:26px 26px;
  mask-image:linear-gradient(180deg, rgba(0,0,0,.32), transparent 72%);
  pointer-events:none;
}
a{color:inherit;text-decoration:none}
img{max-width:100%;display:block}
.site-top{
  position:sticky;
  top:0;
  z-index:30;
  display:flex;
  justify-content:space-between;
  align-items:center;
  gap:18px;
  padding:14px max(20px, calc((100vw - 1220px)/2));
  backdrop-filter:blur(16px);
  background:rgba(251,248,242,.82);
  border-bottom:1px solid rgba(120,103,79,.16);
}
.brand{
  font-family:var(--serif);
  font-size:20px;
  letter-spacing:.02em;
  font-weight:700;
}
.top-nav{display:flex;flex-wrap:wrap;gap:10px}
.top-nav a{
  padding:7px 12px;
  border:1px solid rgba(22,53,47,.12);
  border-radius:999px;
  color:var(--muted);
  font-size:14px;
  background:rgba(255,255,255,.56);
}
.page{
  width:min(1220px, calc(100vw - 32px));
  margin:0 auto;
  padding:24px 0 60px;
}
.hero{
  margin:16px 0 28px;
  padding:34px;
  border-radius:30px;
  background:
    linear-gradient(135deg, rgba(138,95,60,.12), rgba(255,255,255,.84)),
    radial-gradient(circle at 85% 18%, rgba(45,107,107,.16), transparent 28%);
  border:1px solid rgba(138,95,60,.18);
  box-shadow:var(--shadow);
}
.hero-kicker,.eyebrow{
  display:inline-block;
  color:var(--accent);
  font-size:13px;
  font-weight:800;
  letter-spacing:.08em;
  text-transform:uppercase;
}
.hero h1{
  margin:14px 0 10px;
  font-family:var(--serif);
  font-size:clamp(34px, 4.6vw, 58px);
  line-height:1.08;
}
.hero-subtitle{
  margin:0 0 12px;
  max-width:960px;
  font-size:19px;
  color:var(--muted);
}
.hero-intro{
  margin:0;
  max-width:930px;
  font-size:16px;
}
.overview-grid,
.card-grid{
  display:grid;
  gap:18px;
}
.overview-grid{grid-template-columns:repeat(auto-fit,minmax(240px,1fr));margin-bottom:24px}
.overview-card,
.content-panel,
.side-card,
.card,
.path-panel{
  border:1px solid rgba(138,95,60,.16);
  background:rgba(251,248,242,.86);
  border-radius:24px;
  box-shadow:var(--shadow);
}
.overview-card,.content-panel,.side-card{padding:24px}
.overview-card h2,.content-panel h2,.side-card h2{
  margin:10px 0 12px;
  font-family:var(--serif);
  line-height:1.24;
}
.content-section{margin-top:28px}
.section-head{
  display:flex;
  justify-content:space-between;
  align-items:end;
  gap:18px;
  margin-bottom:16px;
}
.section-head h2{
  margin:10px 0 0;
  font-family:var(--serif);
  line-height:1.2;
}
.section-link{
  padding:11px 14px;
  border-radius:999px;
  background:var(--ink);
  color:#f6f3ed;
  white-space:nowrap;
}
.chapter-grid{grid-template-columns:repeat(auto-fit,minmax(270px,1fr))}
.concept-grid{grid-template-columns:repeat(auto-fit,minmax(250px,1fr))}
.plate-grid{grid-template-columns:repeat(auto-fit,minmax(240px,1fr))}
.card{
  padding:18px;
  transition:transform .22s ease, border-color .22s ease, box-shadow .22s ease;
}
.card:hover{
  transform:translateY(-3px);
  border-color:rgba(45,107,107,.28);
}
.card h3{
  margin:12px 0 10px;
  font-family:var(--serif);
  line-height:1.28;
}
.card p{margin:0;color:var(--muted);font-size:15px}
.card-badge{
  display:inline-flex;
  align-items:center;
  padding:6px 10px;
  border-radius:999px;
  background:rgba(138,95,60,.12);
  color:var(--accent);
  font-size:12px;
  font-weight:800;
  letter-spacing:.06em;
}
.card-meta{
  display:flex;
  justify-content:space-between;
  gap:12px;
  margin-top:16px;
  color:var(--muted);
  font-size:13px;
}
.card-thumb{
  aspect-ratio:1.45/1;
  padding:12px;
  border-radius:18px;
  background:#f2ede4;
  border:1px solid rgba(22,53,47,.08);
}
.card-thumb img{
  width:100%;
  height:100%;
  object-fit:contain;
}
.two-col{
  display:grid;
  grid-template-columns:minmax(0, 1.6fr) minmax(300px, .9fr);
  gap:20px;
}
.single-bias{grid-template-columns:minmax(0, 1fr)}
.main-col,.side-col{display:grid;gap:20px}
.dual-panel{
  display:grid;
  grid-template-columns:repeat(auto-fit,minmax(240px,1fr));
  gap:20px;
}
.bullet-list,.route-list{
  margin:0;
  padding-left:20px;
  display:grid;
  gap:10px;
}
.route-list li span{display:block;color:var(--muted);font-size:14px}
.deep-grid{
  display:grid;
  gap:14px;
  grid-template-columns:repeat(auto-fit,minmax(230px,1fr));
}
.deep-card{
  padding:16px;
  border-radius:18px;
  background:#f6f1e8;
  border:1px solid rgba(22,53,47,.08);
}
.deep-card h3{
  margin:0 0 10px;
  font-size:17px;
  font-family:var(--serif);
}
.deep-card p{margin:8px 0 0;color:var(--muted)}
.viewer{display:grid;gap:12px}
.viewer-main{
  width:100%;
  border-radius:18px;
  background:#f2ede4;
  padding:14px;
  border:1px solid rgba(22,53,47,.08);
  object-fit:contain;
}
.viewer-caption strong{display:block;font-family:var(--serif);margin-bottom:4px}
.viewer-caption p{margin:0;color:var(--muted);font-size:14px}
.viewer-thumbs{
  display:grid;
  grid-template-columns:repeat(auto-fit,minmax(72px,1fr));
  gap:10px;
}
.viewer-thumb{
  padding:0;
  border:none;
  background:none;
  border-radius:14px;
  overflow:hidden;
  cursor:pointer;
  outline:2px solid transparent;
}
.viewer-thumb img{
  width:100%;
  aspect-ratio:1/1;
  object-fit:contain;
  padding:8px;
  background:#f2ede4;
  border:1px solid rgba(22,53,47,.08);
}
.viewer-thumb.is-active{outline-color:var(--accent-2)}
.viewer-empty{
  min-height:180px;
  padding:18px;
  border-radius:18px;
  background:#f6f1e8;
}
.excerpt-block{
  margin:0;
  padding:18px 20px;
  border-left:4px solid rgba(138,95,60,.4);
  color:var(--muted);
  background:#f6f1e8;
  border-radius:16px;
}
.qa summary{
  cursor:pointer;
  font-weight:700;
  font-family:var(--serif);
}
.qa-body{padding-top:10px;color:var(--muted)}
.plate-group h3{
  margin:0 0 12px;
  font-family:var(--serif);
}
.mini-grid{
  display:grid;
  gap:14px;
  grid-template-columns:repeat(auto-fit,minmax(220px,1fr));
}
.chip-row,.glossary-preview{
  display:flex;
  flex-wrap:wrap;
  gap:10px;
}
.chip,.glossary-preview span{
  padding:8px 12px;
  border-radius:999px;
  background:#f0e8d9;
  border:1px solid rgba(138,95,60,.14);
  color:var(--muted);
  font-size:14px;
}
.path-panel{
  display:flex;
  flex-wrap:wrap;
  gap:12px;
  padding:18px;
}
.path-link{
  padding:10px 14px;
  border-radius:999px;
  background:#eff4f1;
  color:var(--ink);
  border:1px solid rgba(22,53,47,.1);
}
.glossary-list{
  display:grid;
  gap:16px;
  grid-template-columns:repeat(auto-fit,minmax(260px,1fr));
}
.glossary-item{
  padding:18px;
  border-radius:20px;
  background:rgba(251,248,242,.86);
  border:1px solid rgba(138,95,60,.16);
}
.glossary-item h3{
  margin:0 0 6px;
  font-family:var(--serif);
}
.glossary-en{
  margin:0 0 10px;
  color:var(--accent-2);
  font-size:13px;
  letter-spacing:.04em;
}
.plate-full{
  padding:12px;
  border-radius:22px;
  background:#f2ede4;
  border:1px solid rgba(22,53,47,.08);
}
.plate-full img{
  width:100%;
  object-fit:contain;
  border-radius:16px;
}
@media (max-width: 960px){
  .two-col{grid-template-columns:1fr}
  .site-top{align-items:flex-start;flex-direction:column}
}
@media (max-width: 720px){
  .page{width:min(100vw - 18px, 1220px)}
  .hero{padding:24px 18px;border-radius:24px}
  .content-panel,.side-card,.overview-card,.card{padding:18px}
  .section-head{align-items:flex-start;flex-direction:column}
  .top-nav{gap:8px}
}