:root {
  color-scheme: light;
  --paper: #f7f2e8;
  --ink: #26231f;
  --muted: #746c60;
  --line: rgba(38, 35, 31, 0.16);
  --accent: #596f56;
  --gold: #a06f18;
  --sutra: #7f3329;
  --white: rgba(255, 252, 244, 0.80);
  --serif-zh: "Songti SC", "Noto Serif CJK SC", "STSong", serif;
  --kai-zh: "Kaiti SC", "STKaiti", "KaiTi", "BiauKai", serif;
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background:
    linear-gradient(180deg, rgba(255, 252, 244, 0.70), rgba(239, 230, 208, 0.72)),
    var(--paper);
  color: var(--ink);
  font-family: var(--serif-zh);
  line-height: 1.82;
}

a { color: inherit; text-decoration: none; }
a:hover { color: var(--sutra); }

ruby { ruby-align: center; }

rt {
  color: var(--muted);
  font-family: var(--sans);
  font-size: 0.58em;
  font-weight: 400;
  letter-spacing: 0;
}

.nav-bar {
  min-height: 58px;
  padding: 12px clamp(18px, 4vw, 52px);
  border-bottom: 1px solid var(--line);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  font-family: var(--sans);
  font-size: 14px;
  color: var(--muted);
  background: rgba(255, 252, 244, 0.68);
  backdrop-filter: blur(6px);
}

.home { color: var(--ink); font-weight: 650; }

.hero {
  max-width: 1120px;
  margin: 0 auto;
  padding: clamp(42px, 8vw, 86px) 22px 32px;
  display: grid;
  grid-template-columns: auto 1fr;
  gap: clamp(22px, 5vw, 48px);
  align-items: center;
}

.hero-symbol { display: grid; place-items: center; }

.enso {
  width: 108px;
  height: 108px;
  border: 2px solid rgba(127, 51, 41, 0.64);
  border-radius: 50%;
  display: grid;
  place-items: center;
  color: var(--sutra);
  background: rgba(255, 252, 244, 0.72);
  font-family: var(--kai-zh);
  font-size: 42px;
  line-height: 1;
  box-shadow: 0 12px 26px rgba(38, 35, 31, 0.08);
}

.eyebrow {
  margin: 0 0 10px;
  color: var(--accent);
  font-family: var(--sans);
  font-size: 14px;
  font-weight: 700;
}

h1 {
  margin: 0;
  font-size: clamp(44px, 9vw, 96px);
  line-height: 1.05;
  font-weight: 500;
}

.subtitle {
  margin: 16px 0 0;
  color: var(--muted);
  font-size: clamp(17px, 2vw, 22px);
}

.source-line {
  max-width: 760px;
  margin: 18px 0 0;
  color: var(--muted);
  font-family: var(--sans);
  font-size: 13px;
  line-height: 1.7;
}

.source-line a,
.side-note a { color: var(--accent); }

.overview-band {
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  background: rgba(255, 252, 244, 0.42);
}

.overview-inner {
  width: min(1120px, calc(100% - 32px));
  margin: 0 auto;
  padding: 38px 0 42px;
  display: grid;
  grid-template-columns: minmax(260px, 0.66fr) minmax(0, 1.34fr);
  gap: clamp(24px, 5vw, 54px);
  align-items: start;
}

.overview-lead h2 {
  margin: 0;
  color: var(--ink);
  font-size: clamp(30px, 5vw, 48px);
  line-height: 1.16;
  font-weight: 500;
}

.overview-lead p:last-child {
  margin: 16px 0 0;
  color: var(--muted);
  font-size: 18px;
  line-height: 1.9;
}

.overview-flow {
  list-style: none;
  margin: 0;
  padding: 2px 0 0;
  display: grid;
  gap: 18px;
}

.overview-flow li {
  display: grid;
  grid-template-columns: 34px minmax(0, 1fr);
  gap: 14px;
  align-items: start;
}

.overview-flow li > span {
  width: 30px;
  height: 30px;
  border: 1px solid rgba(160, 111, 24, 0.42);
  border-radius: 50%;
  display: grid;
  place-items: center;
  color: var(--gold);
  background: rgba(255, 252, 244, 0.58);
  font-size: 15px;
  line-height: 1;
}

.overview-flow h3 {
  margin: 0 0 6px;
  color: var(--accent);
  font-family: var(--sans);
  font-size: 15px;
}

.overview-flow p {
  margin: 0;
  color: var(--ink);
  font-size: 16px;
  line-height: 1.82;
}

.directory-head,
.section-index,
.chapter-index {
  width: min(1120px, calc(100% - 32px));
}

.directory-head {
  margin: 34px auto 14px;
}

.directory-head h2 {
  margin: 0;
  color: var(--ink);
  font-size: clamp(28px, 4vw, 42px);
  line-height: 1.2;
  font-weight: 500;
}

.directory-head p:last-child {
  max-width: 680px;
  margin: 10px 0 0;
  color: var(--muted);
  font-family: var(--sans);
  font-size: 15px;
  line-height: 1.75;
}

.section-index,
.chapter-index {
  margin: 0 auto 56px;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 12px;
  align-items: stretch;
}

.section-card,
.chapter-card {
  min-height: 184px;
  border: 1px solid var(--line);
  border-radius: 6px;
  padding: 18px;
  background: var(--white);
  display: grid;
  grid-template-rows: auto auto auto 1fr;
  gap: 4px;
  overflow: hidden;
}

.section-card:hover,
.chapter-card:hover { border-color: rgba(89, 111, 86, 0.46); }

.section-no,
.chapter-no {
  color: var(--gold);
  font-family: var(--sans);
  font-size: 13px;
  font-weight: 700;
}

.section-title,
.chapter-title { font-size: 24px; line-height: 1.25; }

.section-theme,
.chapter-section {
  color: var(--accent);
  font-family: var(--sans);
  font-size: 13px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.section-summary,
.chapter-summary {
  margin-top: 8px;
  color: var(--muted);
  font-size: 15px;
  line-height: 1.65;
  display: -webkit-box;
  overflow: hidden;
  -webkit-box-orient: vertical;
  -webkit-line-clamp: 3;
}

.site-foot,
.section-nav {
  border-top: 1px solid var(--line);
  padding: 22px;
  color: var(--muted);
  text-align: center;
  font-family: var(--sans);
  font-size: 13px;
}

.section-head {
  max-width: 860px;
  margin: 0 auto;
  padding: 46px 22px 18px;
}

.section-head h1 { font-size: clamp(38px, 7vw, 72px); }

.reader-layout {
  width: min(1160px, calc(100% - 32px));
  margin: 0 auto 48px;
  display: grid;
  grid-template-columns: minmax(0, 820px) 280px;
  gap: 34px;
  align-items: start;
}

.reader { width: min(860px, calc(100% - 32px)); }

.reading-block {
  border: 1px solid var(--line);
  border-left-width: 5px;
  border-radius: 0 8px 8px 0;
  margin: 0 0 18px;
  padding: 22px 24px;
  background: rgba(255, 252, 244, 0.70);
}

.reading-block h2 {
  margin: 0 0 12px;
  color: var(--accent);
  font-family: var(--sans);
  font-size: 17px;
  display: flex;
  align-items: center;
  gap: 12px;
}

.reading-block h2::after {
  content: "";
  height: 1px;
  flex: 1;
  background: var(--line);
}

.reading-block p { margin: 0; }
.reading-block p + p { margin-top: 12px; }

.classic-block {
  border-left-color: var(--gold);
  background:
    linear-gradient(180deg, rgba(255, 252, 244, 0.94), rgba(247, 242, 232, 0.74)),
    var(--paper);
  box-shadow: 0 10px 22px rgba(38, 35, 31, 0.08);
}

.vernacular-block {
  border-left-color: var(--accent);
  background: rgba(246, 249, 247, 0.72);
  font-family: var(--sans);
}

.deep-reading { border-left-color: var(--sutra); }
.cross-block { border-left-color: #6f614b; }
.question-block { border-left-color: #8e7a3f; }

.classic-with-terms {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(230px, 280px);
  gap: 24px;
  align-items: start;
}

.classic-text {
  min-width: 0;
  font-family: var(--kai-zh);
  overflow-wrap: anywhere;
}

.classic-text p {
  font-size: 23px;
  line-height: 2.34;
}

.classic-text rt {
  font-size: 0.52em;
  line-height: 1;
}

.terms-aside {
  border-left: 1px solid rgba(160, 111, 24, 0.32);
  padding-left: 18px;
}

.terms-aside h3 {
  margin: 0 0 12px;
  color: var(--gold);
  font-family: var(--sans);
  font-size: 14px;
  font-weight: 700;
}

.vernacular-block p {
  position: relative;
  padding-left: 14px;
  color: var(--ink);
  font-size: 18px;
  line-height: 1.9;
}

.vernacular-block p::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.55em;
  bottom: 0.55em;
  width: 3px;
  background: rgba(89, 111, 86, 0.28);
  border-radius: 99px;
}

.deep-reading p {
  font-size: 19px;
  line-height: 1.88;
}

.placeholder { color: var(--muted); }

.term-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 9px;
}

.term-item {
  border: 1px solid var(--line);
  border-radius: 6px;
  padding: 11px 12px;
  background: var(--white);
}

.term-name {
  display: block;
  color: var(--gold);
  font-size: 21px;
  line-height: 1.3;
}

.term-desc {
  display: block;
  margin-top: 6px;
  color: var(--muted);
  font-size: 15px;
  line-height: 1.65;
}

.cross-list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  gap: 12px;
}

.cross-list li {
  border-left: 3px solid rgba(160, 111, 24, 0.58);
  padding: 6px 0 7px 14px;
}

.cross-source {
  display: block;
  color: var(--accent);
  font-family: var(--sans);
  font-size: 14px;
  font-weight: 700;
}

.cross-text {
  display: block;
  margin-top: 5px;
  font-size: 17px;
  line-height: 1.78;
}

.question-block ol {
  margin: 0;
  padding-left: 22px;
}

.question-block li {
  padding-left: 4px;
  font-size: 18px;
  line-height: 1.82;
}

.question-block li + li { margin-top: 8px; }

.reader-aside {
  position: sticky;
  top: 18px;
}

.side-panel {
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 18px;
  background: var(--white);
}

.side-panel h3 {
  margin: 0 0 12px;
  color: var(--accent);
  font-family: var(--sans);
  font-size: 15px;
}

.side-item {
  border-top: 1px solid var(--line);
  padding: 10px 0;
}

.side-item span {
  display: block;
  color: var(--muted);
  font-family: var(--sans);
  font-size: 12px;
}

.side-item b {
  display: block;
  margin-top: 2px;
  font-size: 18px;
  font-weight: 500;
}

.side-note {
  border-top: 1px solid var(--line);
  padding-top: 12px;
  color: var(--muted);
  font-family: var(--sans);
  font-size: 12px;
  line-height: 1.65;
}

.section-nav {
  display: flex;
  justify-content: center;
  gap: 28px;
}

@media (max-width: 1020px) {
  .reader-layout { grid-template-columns: 1fr; }
  .reader {
    width: 100%;
    max-width: 860px;
  }
  .reader-aside {
    position: static;
    max-width: 860px;
  }
}

@media (max-width: 720px) {
  .hero,
  .overview-inner { grid-template-columns: 1fr; }
  .enso { width: 84px; height: 84px; font-size: 34px; }
  .nav-bar {
    align-items: flex-start;
    flex-direction: column;
  }
  .classic-with-terms { grid-template-columns: 1fr; }
  .terms-aside {
    border-left: 0;
    border-top: 1px solid rgba(160, 111, 24, 0.32);
    padding: 16px 0 0;
  }
  .reading-block { padding: 18px 16px; }
  .classic-text p {
    font-size: 21px;
    line-height: 2.32;
  }
}