:root {
  --bg: #f6f1e8;
  --paper: #fbf7f1;
  --ink: #22201a;
  --muted: #6d6659;
  --line: #d8cdbb;
  --accent: #8d4c24;
  --accent-soft: #f1dfca;
  --shadow: 0 18px 50px rgba(68, 47, 22, 0.08);
  --font-head: "Songti SC", "Noto Serif SC", serif;
  --font-body: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
}
* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: var(--font-body);
  color: var(--ink);
  background:
    radial-gradient(circle at top left, rgba(196, 156, 110, 0.15), transparent 32%),
    linear-gradient(180deg, #f8f3ec 0%, var(--bg) 100%);
}
a { color: inherit; }
img { display: block; max-width: 100%; }
.topbar {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  align-items: center;
  justify-content: space-between;
  padding: 16px 24px;
  background: rgba(251, 247, 241, 0.88);
  backdrop-filter: blur(18px);
  border-bottom: 1px solid rgba(141, 76, 36, 0.12);
}
.brand {
  font-family: var(--font-head);
  font-size: 1.05rem;
  text-decoration: none;
  font-weight: 700;
}
.path-panel {
  padding: 8px 12px;
  border-radius: 999px;
  background: rgba(141, 76, 36, 0.08);
  color: var(--muted);
  font-size: 0.92rem;
}
.top-actions {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
}
.page-shell {
  width: min(1200px, calc(100% - 32px));
  margin: 0 auto;
  padding: 32px 0 72px;
}
.hero {
  display: grid;
  grid-template-columns: minmax(0, 1.4fr) minmax(260px, 0.8fr);
  gap: 28px;
  padding: 32px;
  border-radius: 28px;
  background: linear-gradient(145deg, rgba(255,255,255,0.95), rgba(248, 238, 223, 0.96));
  box-shadow: var(--shadow);
  border: 1px solid rgba(141, 76, 36, 0.1);
}
.chapter-hero { grid-template-columns: 1fr; }
.eyebrow {
  margin: 0 0 10px;
  font-size: 0.82rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--accent);
  font-weight: 700;
}
h1, h2, h3, h4 {
  font-family: var(--font-head);
  margin: 0 0 12px;
}
h1 { font-size: clamp(2rem, 3vw, 3.2rem); line-height: 1.15; }
h2 { font-size: 1.5rem; }
h3 { font-size: 1.1rem; }
.lead {
  margin: 0 0 16px;
  font-size: 1.05rem;
  line-height: 1.8;
  color: #463d32;
}
.hero-cover img {
  width: 100%;
  height: 100%;
  object-fit: contain;
  padding: 24px;
  background: linear-gradient(180deg, #f7efe3, #efe2cf);
  border-radius: 20px;
}
.hero-metrics {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 12px;
  margin-top: 24px;
}
.hero-metrics div {
  padding: 14px;
  border-radius: 18px;
  background: rgba(141, 76, 36, 0.08);
}
.hero-metrics strong {
  display: block;
  font-size: 1.6rem;
  font-family: var(--font-head);
}
.section-block { margin-top: 34px; }
.section-heading {
  display: flex;
  justify-content: space-between;
  gap: 20px;
  align-items: end;
  margin-bottom: 18px;
}
.section-heading p { margin: 0; color: var(--muted); line-height: 1.7; max-width: 720px; }
.card-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
}
.card-grid-wide { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.card, .info-card, .viewer-card, .question-card, .mini-card, .glossary-item, .plate-learning-cluster {
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 22px;
  box-shadow: var(--shadow);
}
.card, .mini-card, .glossary-item, .plate-learning-cluster { padding: 20px; }
.info-card, .viewer-card, .question-card { padding: 24px; }
.card p, .info-card p, .mini-card p, .glossary-item p, .plate-learning-cluster p, li, blockquote {
  line-height: 1.78;
  color: #40392f;
}
.chip-row {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 14px;
}
.chip {
  display: inline-flex;
  align-items: center;
  padding: 8px 12px;
  border-radius: 999px;
  background: var(--accent-soft);
  color: #6a3718;
  font-size: 0.88rem;
  text-decoration: none;
}
.chip-link { border: 1px solid rgba(141, 76, 36, 0.16); }
.plate-strip, .plate-list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
}
.plate-thumb-card, .plate-card, .gallery-card {
  text-decoration: none;
  display: block;
  padding: 14px;
  border-radius: 20px;
  background: var(--paper);
  border: 1px solid var(--line);
  box-shadow: var(--shadow);
}
.gallery-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
}
.thumb-shell {
  aspect-ratio: 4 / 3;
  display: grid;
  place-items: center;
  padding: 16px;
  background: linear-gradient(180deg, #f7f3ed, #efe5d6);
  border-radius: 16px;
  overflow: hidden;
}
.thumb-shell img {
  width: 100%;
  height: 100%;
  object-fit: contain;
}
.mini-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
}
.mini-term {
  padding: 16px;
  border-radius: 18px;
  background: rgba(141, 76, 36, 0.06);
}
.mini-term p { margin: 0; color: var(--muted); }
.content-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.4fr) minmax(280px, 0.8fr);
  gap: 24px;
  margin-top: 28px;
}
.main-column, .side-column {
  display: flex;
  flex-direction: column;
  gap: 18px;
}
.split-card {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px;
}
.answer-toggle, .thumb-button {
  cursor: pointer;
  border: 0;
}
.answer-toggle {
  margin-top: 12px;
  padding: 11px 16px;
  border-radius: 999px;
  background: var(--accent);
  color: #fff;
  font-weight: 600;
}
.answer-panel {
  margin-top: 14px;
  padding: 16px;
  border-radius: 16px;
  background: rgba(141, 76, 36, 0.08);
}
.deep-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px;
}
.source-item-deep {
  padding: 22px;
  border-radius: 20px;
  background: linear-gradient(180deg, #fffefa, #f5eee3);
  border: 1px solid var(--line);
  box-shadow: var(--shadow);
}
.deep-label {
  margin-top: 14px;
  margin-bottom: 6px;
  font-size: 0.84rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--accent);
  font-weight: 700;
}
blockquote {
  margin: 14px 0 0;
  padding: 16px;
  border-left: 4px solid rgba(141, 76, 36, 0.4);
  background: rgba(141, 76, 36, 0.06);
  border-radius: 12px;
}
.viewer-main, .full-plate {
  width: 100%;
  border-radius: 18px;
  background: linear-gradient(180deg, #f7f2e7, #efe3d1);
  padding: 18px;
}
.viewer-thumbs {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
  margin-top: 14px;
}
.thumb-button {
  padding: 0;
  width: 92px;
  border-radius: 14px;
  overflow: hidden;
  background: transparent;
}
.thumb-button img {
  width: 92px;
  height: 72px;
  object-fit: contain;
  background: #f4eadb;
  padding: 8px;
}
.cluster-list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px;
}
.ghost-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  text-decoration: none;
  padding: 10px 14px;
  border-radius: 999px;
  border: 1px solid rgba(141, 76, 36, 0.18);
  background: rgba(255,255,255,0.66);
}
.link-stack {
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.pager {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  margin-top: 8px;
}
.pager a {
  flex: 1;
  text-align: center;
  padding: 14px 16px;
  border-radius: 16px;
  text-decoration: none;
  background: #efe2cf;
  border: 1px solid rgba(141, 76, 36, 0.14);
}
.two-column {
  display: grid;
  grid-template-columns: minmax(0, 1.1fr) minmax(280px, 0.9fr);
  gap: 22px;
}
.glossary-list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px;
  margin-top: 26px;
}
.glossary-en {
  color: var(--accent);
  font-size: 0.9rem;
  margin-top: -4px;
}
@media (max-width: 980px) {
  .hero, .content-grid, .two-column, .split-card, .card-grid, .card-grid-wide, .deep-grid, .cluster-list, .gallery-grid, .glossary-list {
    grid-template-columns: 1fr;
  }
  .plate-strip, .plate-list, .mini-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .hero-metrics {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}
@media (max-width: 640px) {
  .topbar { padding: 14px 16px; }
  .page-shell { width: min(100% - 20px, 1200px); padding-top: 18px; }
  .hero, .info-card, .viewer-card, .question-card { padding: 20px; }
  .plate-strip, .plate-list, .mini-grid { grid-template-columns: 1fr; }
  .pager { flex-direction: column; }
}