:root{
  --bg:#fbf5ef;
  --paper:#fffdfa;
  --ink:#1f2430;
  --muted:#656d7c;
  --line:#e4d8cd;
  --accent:#a5572a;
  --accent-soft:#f3e4d5;
  --sage:#7d8f84;
  --rose:#d8a7a1;
  --shadow:0 18px 46px rgba(31,36,48,.08);
  --radius:22px;
  --serif:"Iowan Old Style","Songti SC","STSong","Noto Serif SC",serif;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{
  margin:0;
  color:var(--ink);
  font-family:"PingFang SC","Hiragino Sans GB","Microsoft YaHei",sans-serif;
  line-height:1.72;
  background:
    radial-gradient(circle at top left, rgba(216,167,161,.18), transparent 30%),
    radial-gradient(circle at top right, rgba(125,143,132,.16), transparent 28%),
    linear-gradient(180deg,#fdf9f4,#f7efe7 58%,#f6efe8);
}
a{color:inherit}
img{display:block;max-width:100%}
.shell{width:min(1220px,calc(100vw - 32px));margin:0 auto;padding:24px 0 56px}
.nav{display:flex;justify-content:space-between;align-items:flex-start;gap:16px;margin-bottom:24px}
.brand{font-size:28px;font-weight:800;line-height:1.16}
.crumbs,.meta{font-size:13px;color:var(--muted)}
.crumbs a{text-decoration:none;margin-right:10px}
.nav-links{display:flex;gap:10px;flex-wrap:wrap;justify-content:flex-end}
.nav-links a,.button{
  display:inline-flex;align-items:center;justify-content:center;
  min-height:42px;padding:0 16px;border-radius:999px;border:1px solid var(--line);
  background:rgba(255,255,255,.84);backdrop-filter:blur(10px);text-decoration:none;font-weight:700
}
.hero,.layout,.grid,.stats,.glossary-list,.chapter-map{display:grid;gap:18px}
.hero{grid-template-columns:1.2fr .9fr}
.layout{grid-template-columns:minmax(0,2fr) minmax(310px,1fr)}
.grid.cols-2{grid-template-columns:repeat(2,minmax(0,1fr))}
.grid.cols-3{grid-template-columns:repeat(3,minmax(0,1fr))}
.grid.cols-4{grid-template-columns:repeat(4,minmax(0,1fr))}
.stats{grid-template-columns:repeat(5,minmax(0,1fr))}
.chapter-map{grid-template-columns:repeat(2,minmax(0,1fr))}
.glossary-list{grid-template-columns:repeat(2,minmax(0,1fr))}
.section{margin-top:24px}
.section-head{display:flex;justify-content:space-between;align-items:end;gap:16px;margin-bottom:12px}
.card,.reading-card,.side-card,.plate-card,.group-card,.stat-card,.path-card,.question-card,.viewer,.glossary-card,.chapter-card,.concept-card,.callout{
  background:var(--paper);border:1px solid rgba(228,216,205,.92);border-radius:var(--radius);box-shadow:var(--shadow)
}
.card,.reading-card,.side-card,.question-card,.viewer,.glossary-card,.callout,.chapter-card,.concept-card,.group-card{padding:22px}
.plate-card,.path-card,.stat-card{padding:18px}
.page-title,h1,h2,h3{margin:0 0 10px}
.page-title,h1,h2,.quote{font-family:var(--serif)}
.page-title{font-size:clamp(28px,4vw,46px);line-height:1.12}
.subtitle{max-width:66ch;color:var(--muted);font-size:16px}
.quote{font-size:28px;line-height:1.42}
.kicker{font-size:12px;font-weight:800;letter-spacing:.08em;text-transform:uppercase;color:var(--accent);margin-bottom:8px}
.cover{
  aspect-ratio:4/5;border-radius:18px;border:1px solid var(--line);overflow:hidden;
  background:
    linear-gradient(180deg,rgba(255,255,255,.7),rgba(255,255,255,.95)),
    radial-gradient(circle at top, rgba(216,167,161,.18), transparent 55%);
}
.cover img{width:100%;height:100%;object-fit:contain;padding:16px}
.thumb{
  aspect-ratio:1.05/1;border-radius:18px;border:1px solid var(--line);overflow:hidden;
  background:linear-gradient(180deg,#fffdf8,#f4ece2)
}
.thumb img{width:100%;height:100%;object-fit:contain;padding:12px}
.stack{display:grid;gap:16px}
.chips{display:flex;flex-wrap:wrap;gap:8px}
.chip{
  display:inline-flex;align-items:center;min-height:30px;padding:0 10px;border-radius:999px;
  background:var(--accent-soft);color:var(--accent);text-decoration:none;font-size:12px;font-weight:800
}
.list{margin:0;padding-left:20px}
.list li+li{margin-top:8px}
.search{width:100%;min-height:46px;border-radius:14px;border:1px solid var(--line);padding:0 14px;font:inherit;background:#fff}
.viewer-main{
  aspect-ratio:4/3;border-radius:18px;border:1px solid var(--line);overflow:hidden;
  background:linear-gradient(180deg,#fffdfa,#f3ece2);display:flex;align-items:center;justify-content:center
}
.viewer-main img,.plate-full{width:100%;height:100%;object-fit:contain;padding:16px}
.thumbs{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:10px}
.thumbs button{padding:0;border:0;background:none;cursor:pointer}
.deep-grid{display:grid;gap:12px}
.source-item-deep{padding:16px;border-radius:18px;border:1px solid var(--line);background:#fbf7f2}
.source-item-deep p{margin:0 0 10px}
.source-item-deep p:last-child{margin-bottom:0}
.question-answer{display:none;margin-top:12px;padding:14px;border-radius:16px;background:#f6efe6}
.question-answer.is-open{display:block}
.page-footer{display:flex;gap:16px;margin-top:20px}
.page-footer a,.page-footer span{
  flex:1;min-height:82px;padding:16px;border-radius:18px;border:1px solid var(--line);
  background:var(--paper);text-decoration:none
}
.group-card h3,.chapter-card h3,.concept-card h3,.plate-card h3,.path-card h3{font-size:20px}
.chapter-card,.concept-card,.plate-card,.path-card,.group-card{display:block;text-decoration:none;transition:transform .16s ease, box-shadow .16s ease}
.chapter-card:hover,.concept-card:hover,.plate-card:hover,.path-card:hover,.group-card:hover{transform:translateY(-2px)}
.hidden{display:none!important}
@media (max-width:1024px){
  .hero,.layout,.stats,.grid.cols-4,.grid.cols-3,.grid.cols-2,.glossary-list,.chapter-map{grid-template-columns:1fr 1fr}
}
@media (max-width:720px){
  .shell{width:min(100vw - 20px,1220px)}
  .nav{flex-direction:column}
  .nav-links{justify-content:flex-start}
  .hero,.layout,.stats,.grid.cols-4,.grid.cols-3,.grid.cols-2,.glossary-list,.chapter-map{grid-template-columns:1fr}
  .thumbs{grid-template-columns:repeat(2,minmax(0,1fr))}
}