:root{
  --bg:#f3efe6;
  --bg-soft:#ede6d8;
  --paper:#fbf8f1;
  --ink:#1f2a22;
  --muted:#687566;
  --line:#d7cfbf;
  --accent:#31533f;
  --accent-soft:#dce8dc;
  --warm:#a66a3f;
  --shadow:0 16px 40px rgba(45, 40, 29, .08);
  --radius:18px;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{
  margin:0;
  font-family:"Avenir Next","PingFang SC","Hiragino Sans GB","Noto Sans CJK SC",sans-serif;
  color:var(--ink);
  background:
    radial-gradient(circle at top right, rgba(166,106,63,.12), transparent 28%),
    linear-gradient(180deg, #f7f2e8 0%, var(--bg) 100%);
  line-height:1.7;
}
a{color:var(--accent);text-decoration:none}
a:hover{text-decoration:underline}
img{max-width:100%;display:block}
.shell{max-width:1240px;margin:0 auto;padding:0 24px 72px}
.topbar{
  display:flex;justify-content:space-between;align-items:center;gap:16px;
  padding:20px 0;border-bottom:1px solid rgba(49,83,63,.12);margin-bottom:18px;
}
.brand{display:flex;align-items:center;gap:12px;color:var(--ink);font-weight:700}
.brand:hover{text-decoration:none}
.brand-mark{
  width:40px;height:40px;border-radius:14px;background:linear-gradient(135deg,var(--accent),#50785d);
  color:#fff;display:grid;place-items:center;font-size:20px;box-shadow:var(--shadow)
}
.nav{display:flex;gap:18px;flex-wrap:wrap}
.nav a{color:var(--muted);font-size:14px}
.hero,.reader-layout,.info-grid,.chapter-grid,.concept-grid,.plate-grid,.visual-strip,.stats,.learning-nav,.mini-grid{
  display:grid;gap:20px
}
.hero{grid-template-columns:minmax(0,1.4fr) 360px;align-items:start;padding:28px 0 10px}
.hero-copy h1,.page-hero h1{
  margin:8px 0 14px;font-family:"Iowan Old Style","Songti SC","Noto Serif CJK SC",serif;
  font-weight:700;letter-spacing:0;font-size:clamp(34px,4vw,58px);line-height:1.08
}
.page-hero h1{font-size:clamp(28px,3vw,44px)}
.subtitle{font-size:18px;color:#364438;max-width:780px}
.eyebrow,.kicker{
  text-transform:uppercase;letter-spacing:.08em;font-size:12px;color:var(--warm);font-weight:700
}
.chip-row{display:flex;gap:10px;flex-wrap:wrap;margin:18px 0}
.chip,.route-pill{
  border:1px solid rgba(49,83,63,.15);background:rgba(255,255,255,.62);
  border-radius:999px;padding:8px 12px;font-size:13px;color:#415143
}
.hero-actions,.learning-nav{display:flex;gap:12px;flex-wrap:wrap;margin-top:18px}
.button{
  display:inline-flex;align-items:center;justify-content:center;padding:11px 16px;border-radius:999px;
  border:1px solid rgba(49,83,63,.18);background:#fff;color:var(--ink);font-weight:600
}
.button.primary{background:var(--accent);color:#fff;border-color:var(--accent)}
.button:hover{text-decoration:none;transform:translateY(-1px)}
.paper-note,.aside-card,.cover-card,.info-card,.chapter-card,.concept-card,.plate-card,.reading-card,.plate-group,.question-card details{
  background:rgba(255,255,255,.78);backdrop-filter:blur(8px);border:1px solid rgba(49,83,63,.1);
  border-radius:var(--radius);box-shadow:var(--shadow)
}
.paper-note{padding:18px 20px;margin-top:18px}
.stats{grid-template-columns:repeat(2,minmax(0,1fr));margin-top:18px}
.stat{padding:16px 18px;background:rgba(255,255,255,.7);border:1px solid rgba(49,83,63,.1);border-radius:16px}
.stat strong{display:block;margin-bottom:6px}
.cover-card,.aside-card{padding:18px}
.cover-card img{
  width:100%;aspect-ratio:4/5;object-fit:contain;background:linear-gradient(180deg,#efe7d6,#f8f3eb);
  border-radius:14px;padding:14px;border:1px solid var(--line)
}
.cover-card small,.muted{color:var(--muted)}
.section{padding-top:28px}
.section-head{display:flex;justify-content:space-between;gap:16px;align-items:end;margin-bottom:18px}
.section-head h2,.info-card h2,.plate-group h3,.reading-card h3,.chapter-card h3,.concept-card h3,.plate-card h3{
  margin:6px 0 0;font-family:"Iowan Old Style","Songti SC","Noto Serif CJK SC",serif;line-height:1.2
}
.section-head p{max-width:720px;color:var(--muted);margin:0}
.visual-strip,.plate-grid{grid-template-columns:repeat(auto-fit,minmax(220px,1fr))}
.chapter-grid{grid-template-columns:repeat(auto-fit,minmax(260px,1fr))}
.concept-grid{grid-template-columns:repeat(auto-fit,minmax(220px,1fr))}
.visual-card,.plate-card{overflow:hidden}
.visual-card,.plate-card,.concept-card,.chapter-card,.info-card,.reading-card,.plate-group{padding:18px}
.visual-card img,.plate-card img,.thumb-button img,.mini-thumb img{
  width:100%;aspect-ratio:4/3;object-fit:contain;background:var(--bg-soft);padding:12px;border-radius:12px;border:1px solid var(--line)
}
.visual-card span,.plate-card-copy h3{display:block;margin-top:12px}
.plate-card-copy p,.chapter-card p,.concept-card p,.info-card p,.reading-card p{margin:10px 0 0;color:#3f4d40}
.content{padding-top:12px}
.page-hero{padding:16px 0 8px}
.info-grid{grid-template-columns:repeat(2,minmax(0,1fr))}
.knowledge-route{display:flex;gap:12px;flex-wrap:wrap}
.route-pill{display:flex;flex-direction:column;gap:4px;border-radius:18px}
.route-pill small{font-size:12px;color:var(--muted)}
.list{padding-left:18px;margin:0}
.list li+li{margin-top:10px}
.reader-layout{grid-template-columns:minmax(0,1fr) 320px}
.reader-main{display:grid;gap:20px}
.reader-side{display:block}
.sticky{position:sticky;top:20px}
.plate-main{
  width:100%;aspect-ratio:4/5;object-fit:contain;background:var(--paper);padding:12px;border-radius:14px;border:1px solid var(--line);margin:12px 0
}
.thumb-list{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:10px}
.thumb-button{border:0;background:transparent;padding:0;cursor:pointer}
.thumb-button img{aspect-ratio:1/1;padding:8px}
.reading-grid{grid-template-columns:repeat(3,minmax(0,1fr))}
.mini-grid{grid-template-columns:repeat(auto-fit,minmax(240px,1fr))}
.plate-mini{
  display:grid;grid-template-columns:80px minmax(0,1fr);gap:12px;align-items:start;
  padding:12px;border-radius:14px;background:#fff;border:1px solid rgba(49,83,63,.08)
}
.mini-thumb img{aspect-ratio:1/1;padding:6px}
.question-card details{padding:18px}
.question-card summary{cursor:pointer;font-weight:700}
.search{
  width:100%;padding:14px 16px;border-radius:14px;border:1px solid var(--line);
  background:#fff;margin-bottom:16px;font:inherit
}
.hidden{display:none!important}
.plate-figure img{
  width:100%;max-height:78vh;object-fit:contain;background:var(--paper);padding:18px;
  border-radius:var(--radius);border:1px solid var(--line);box-shadow:var(--shadow)
}
.glossary-table{width:100%;border-collapse:collapse;background:#fff;border-radius:16px;overflow:hidden}
.glossary-table th,.glossary-table td{padding:14px 16px;border-bottom:1px solid var(--line);text-align:left;vertical-align:top}
.glossary-table th{background:var(--bg-soft)}
@media (max-width: 980px){
  .hero,.reader-layout,.info-grid,.reading-grid{grid-template-columns:1fr}
  .reader-side{order:-1}
}
@media (max-width: 720px){
  .shell{padding:0 16px 56px}
  .topbar{flex-direction:column;align-items:flex-start}
  .stats,.thumb-list{grid-template-columns:1fr 1fr}
  .nav{gap:12px}
}