:root{
  --bg:#f6f0e6;
  --paper:#fffdf9;
  --paper-soft:#fbf7f1;
  --card:#fff8f0;
  --line:#dbcbb8;
  --text:#2d261f;
  --muted:#6d6258;
  --accent:#b46838;
  --accent-2:#496b5f;
  --shadow:0 20px 50px rgba(72,49,31,.10);
}
body[data-theme="dark"]{
  --bg:#1d1916;
  --paper:#2a241f;
  --paper-soft:#322a24;
  --card:#342c26;
  --line:#5d4f43;
  --text:#f4ede1;
  --muted:#cdbfb2;
  --accent:#f0a167;
  --accent-2:#8eb5aa;
  --shadow:0 20px 50px rgba(0,0,0,.35);
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{
  margin:0;
  color:var(--text);
  font-family:"PingFang SC","Hiragino Sans GB","Noto Sans SC","Microsoft YaHei",sans-serif;
  background:
    radial-gradient(circle at top left, rgba(180,104,56,.12), transparent 24rem),
    radial-gradient(circle at top right, rgba(73,107,95,.12), transparent 26rem),
    linear-gradient(180deg, var(--paper-soft), var(--bg));
}
a{color:inherit;text-decoration:none}
img{display:block;max-width:100%}
main{max-width:1240px;margin:0 auto;padding:28px 20px 80px}
.topbar{
  position:sticky;top:0;z-index:20;
  display:flex;align-items:center;justify-content:space-between;gap:16px;
  padding:16px 20px;border-bottom:1px solid rgba(0,0,0,.06);
  backdrop-filter:blur(14px);background:rgba(255,251,246,.84);
}
body[data-theme="dark"] .topbar{background:rgba(29,25,22,.84);border-bottom-color:rgba(255,255,255,.08)}
.brand{font-weight:800;letter-spacing:.02em}
.topbar nav{display:flex;gap:12px;flex-wrap:wrap}
.topbar nav a{padding:8px 12px;border-radius:999px;color:var(--muted)}
.topbar nav a.active,.topbar nav a:hover{background:var(--paper);color:var(--text)}
.button,.ghost-button,.icon-button{
  border:none;border-radius:999px;padding:11px 16px;cursor:pointer;font-weight:700;
}
.button{background:linear-gradient(135deg,var(--accent),#cf8756);color:#fff;box-shadow:var(--shadow)}
.ghost-button{border:1px solid var(--line);background:var(--paper);color:var(--text)}
.icon-button{background:linear-gradient(135deg,var(--accent),#cf8756);color:#fff}
.hero,.hero-book{
  background:linear-gradient(135deg, rgba(255,255,255,.90), rgba(255,247,238,.78));
  border:1px solid rgba(255,255,255,.58);border-radius:30px;box-shadow:var(--shadow);
}
body[data-theme="dark"] .hero,body[data-theme="dark"] .hero-book{
  background:linear-gradient(135deg, rgba(57,47,40,.92), rgba(42,36,31,.86));
  border-color:rgba(255,255,255,.08);
}
.hero{display:grid;grid-template-columns:1.3fr .9fr;gap:28px;padding:32px;margin-bottom:24px}
.hero-book{display:grid;grid-template-columns:240px 1fr;gap:28px;padding:28px;margin-bottom:24px}
.hero h1,.hero-book h1{margin:0 0 12px;font-size:clamp(2rem,4vw,3.15rem);line-height:1.08}
.hero p,.hero-book p{margin:0 0 16px;color:var(--muted);line-height:1.82}
.metric-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:14px}
.metric{padding:18px;border-radius:22px;background:var(--paper);border:1px solid var(--line)}
.metric strong{display:block;font-size:2rem;margin-bottom:6px}
.book-cover{
  background:var(--paper);border:1px solid var(--line);border-radius:24px;padding:16px;
  display:flex;align-items:center;justify-content:center;min-height:320px;
}
.book-cover img{max-height:340px;object-fit:contain}
.tag-row,.chip-row{display:flex;flex-wrap:wrap;gap:10px}
.tag,.chip{
  display:inline-flex;align-items:center;border-radius:999px;padding:8px 12px;
  background:rgba(180,104,56,.11);color:var(--accent);font-size:.92rem;font-weight:700;
}
.chip{background:rgba(73,107,95,.12);color:var(--accent-2)}
.section-title{margin:32px 0 14px;font-size:1.5rem}
.grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:18px}
.card,.panel{
  background:var(--card);border:1px solid var(--line);border-radius:28px;padding:22px;box-shadow:var(--shadow);
}
.card h2,.panel h2,.panel h3{margin:0 0 10px}
.card p,.panel p,.panel li,.reading-card p{line-height:1.78;color:var(--muted)}
.small{font-size:.92rem;color:var(--muted)}
.chapter-card-figure,.plate-thumb,.thumb-card,.mini-plate{
  display:block;border:1px solid var(--line);border-radius:22px;overflow:hidden;background:var(--paper);
}
.chapter-card-figure,.plate-thumb,.thumb-card,.mini-plate{padding:12px}
.chapter-card-figure img,.plate-thumb img,.thumb-card img,.mini-plate img{
  width:100%;height:160px;object-fit:contain;background:var(--paper);padding:8px;
}
.searchbar{
  width:100%;padding:14px 18px;border-radius:18px;border:1px solid var(--line);
  background:var(--paper);color:var(--text);margin:0 0 18px;font-size:1rem;
}
.layout{display:grid;grid-template-columns:minmax(0,1fr) 340px;gap:22px}
.sticky-rail{position:sticky;top:88px;display:flex;flex-direction:column;gap:14px}
.route-list,.plain-list,.outline-list{display:grid;gap:10px;padding-left:18px}
.route-list li,.plain-list li,.outline-list li{line-height:1.72}
.reading-grid{display:grid;gap:14px}
.reading-card{padding:18px;border-radius:22px;background:var(--paper);border:1px solid var(--line)}
.qa details{background:var(--paper);border:1px solid var(--line);border-radius:22px;padding:16px 18px}
.qa summary{cursor:pointer;font-weight:800}
.thumb-strip,.cover-band{display:grid;grid-template-columns:repeat(auto-fit,minmax(120px,1fr));gap:12px}
.thumb-card small,.mini-plate small,.plate-thumb small{display:block;margin-top:8px;color:var(--muted)}
.viewer-main{border:1px solid var(--line);border-radius:18px;background:var(--paper);padding:14px;min-height:320px}
.viewer-main img{width:100%;height:420px;object-fit:contain;background:var(--paper)}
.thumb-card{cursor:pointer}
.plate-detail{display:grid;grid-template-columns:minmax(0,1.05fr) minmax(0,.95fr);gap:22px}
.plate-original{
  border:1px solid var(--line);border-radius:24px;background:var(--paper);padding:18px;min-height:420px;
}
.plate-original img{width:100%;height:100%;object-fit:contain;background:var(--paper)}
.glossary-table{display:grid;gap:12px}
.glossary-row{
  display:grid;grid-template-columns:1.15fr .95fr 2fr;gap:16px;align-items:start;
  padding:16px 18px;border-radius:20px;background:var(--paper);border:1px solid var(--line);
}
.pager{display:flex;justify-content:space-between;gap:12px;margin-top:24px}
.pager a{flex:1}
.footer-note{margin-top:24px;color:var(--muted);font-size:.92rem}
.concept-hero{display:grid;grid-template-columns:1fr .85fr;gap:20px}
.book-map{display:grid;gap:10px}
.book-map-item{padding:14px 16px;border-radius:18px;background:var(--paper);border:1px solid var(--line)}
.fade-up{animation:fadeUp .55s ease both}
@keyframes fadeUp{from{opacity:0;transform:translateY(12px)}to{opacity:1;transform:translateY(0)}}
@media (max-width: 980px){
  .hero,.hero-book,.layout,.plate-detail,.concept-hero{grid-template-columns:1fr}
  .grid{grid-template-columns:1fr 1fr}
  .sticky-rail{position:static}
}
@media (max-width: 680px){
  .topbar{align-items:flex-start;flex-direction:column}
  .grid,.metric-grid,.glossary-row{grid-template-columns:1fr}
  .thumb-strip,.cover-band{grid-template-columns:repeat(2,minmax(0,1fr))}
  .viewer-main img{height:300px}
  main{padding-left:14px;padding-right:14px}
  .hero,.hero-book,.card,.panel{padding:18px}
}