:root {
  --paper: #f6f2e8;
  --paper-deep: #ebe3d2;
  --ink: #25251f;
  --muted: #666457;
  --green: #466653;
  --green-deep: #294337;
  --green-wash: #dfe8df;
  --cinnabar: #a44834;
  --gold: #b78a39;
  --line: #d8cfbc;
  --serif: "Songti SC", "Noto Serif SC", STSong, serif;
  --sans: -apple-system, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --mono: "SF Mono", ui-monospace, Menlo, monospace;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; color: var(--ink); background: var(--paper); font-family: var(--sans); font-size: 16px; line-height: 1.85; }
body::before { content: ""; position: fixed; inset: 0; z-index: -1; opacity: .45; background-image: radial-gradient(circle at 1px 1px, rgba(70,102,83,.12) 1px, transparent 0); background-size: 28px 28px; }
a { color: inherit; }
button { font: inherit; }
.wrap { width: min(1080px, calc(100% - 40px)); margin: 0 auto; }
.prose { max-width: 760px; }

.nav { position: sticky; top: 0; z-index: 20; border-bottom: 1px solid var(--ink); background: rgba(246,242,232,.94); backdrop-filter: blur(10px); }
.nav-inner { min-height: 58px; display: flex; align-items: center; gap: 24px; }
.nav-brand { text-decoration: none; font-family: var(--serif); font-weight: 900; letter-spacing: .08em; white-space: nowrap; }
.nav-brand span { color: var(--cinnabar); }
.nav-links { margin-left: auto; display: flex; overflow-x: auto; scrollbar-width: none; }
.nav-links a { padding: 16px 10px 14px; border-bottom: 3px solid transparent; color: var(--muted); text-decoration: none; font-size: 13px; white-space: nowrap; }
.nav-links a:hover, .nav-links a.active { color: var(--green-deep); border-color: var(--cinnabar); }

.hero { min-height: 620px; display: grid; grid-template-columns: 1.2fr .8fr; align-items: center; gap: 50px; padding: 84px 0 72px; }
.eyebrow { margin-bottom: 16px; color: var(--cinnabar); font: 12px/1.4 var(--mono); letter-spacing: .18em; text-transform: uppercase; }
h1, h2, h3 { margin-top: 0; font-family: var(--serif); line-height: 1.3; }
h1 { margin-bottom: 22px; font-size: clamp(42px, 7vw, 76px); letter-spacing: .03em; }
h2 { margin-bottom: 18px; font-size: clamp(28px, 4vw, 40px); }
h3 { margin-bottom: 10px; font-size: 20px; }
.lede { max-width: 680px; color: var(--muted); font-family: var(--serif); font-size: 19px; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 30px; }
.btn { display: inline-block; padding: 10px 18px; border: 1px solid var(--green-deep); background: var(--green-deep); color: #fff; text-decoration: none; font-size: 14px; }
.btn.ghost { background: transparent; color: var(--green-deep); }
.btn:hover { transform: translateY(-2px); }

.dharma-wheel { position: relative; width: min(330px, 72vw); aspect-ratio: 1; margin: auto; border: 1px solid var(--green); border-radius: 50%; box-shadow: 0 0 0 18px var(--green-wash), 0 0 0 19px var(--green); }
.dharma-wheel::before, .dharma-wheel::after { content: ""; position: absolute; inset: 50% 8%; height: 1px; background: var(--green); transform-origin: center; }
.dharma-wheel::after { transform: rotate(90deg); }
.spoke-a, .spoke-b { position: absolute; inset: 50% 8%; height: 1px; background: var(--green); }
.spoke-a { transform: rotate(45deg); }
.spoke-b { transform: rotate(-45deg); }
.wheel-center { position: absolute; inset: 35%; display: grid; place-items: center; border: 1px solid var(--cinnabar); border-radius: 50%; background: var(--paper); color: var(--cinnabar); font: 700 52px/1 var(--serif); }
.wheel-label { position: absolute; inset: auto 0 -70px; text-align: center; color: var(--muted); font: 12px/1.6 var(--mono); letter-spacing: .1em; }

section { padding: 76px 0; border-top: 1px solid var(--line); }
.section-head { display: grid; grid-template-columns: 120px 1fr; gap: 24px; margin-bottom: 32px; }
.section-no { color: var(--cinnabar); font: 12px/1.4 var(--mono); letter-spacing: .15em; }
.grid { display: grid; gap: 20px; }
.cols-2 { grid-template-columns: repeat(2, 1fr); }
.cols-3 { grid-template-columns: repeat(3, 1fr); }
.card { padding: 25px; border: 1px solid var(--line); background: rgba(255,255,255,.42); }
.card:hover { border-color: var(--green); }
.card .tag { display: inline-block; margin-bottom: 14px; color: var(--cinnabar); font: 11px/1.4 var(--mono); letter-spacing: .1em; }
.card p { margin: 0; color: var(--muted); font-size: 14px; }
.card-link { text-decoration: none; }
.card-link .arrow { display: block; margin-top: 16px; color: var(--green); font-weight: 700; }
.quote { margin: 30px 0; padding: 24px 28px; border-left: 3px solid var(--cinnabar); background: var(--green-wash); font-family: var(--serif); font-size: 18px; }
.note { padding: 18px 20px; border: 1px dashed var(--gold); color: var(--muted); font-size: 14px; }

.page-head { padding: 80px 0 58px; border-bottom: 1px solid var(--line); }
.page-head h1 { font-size: clamp(38px, 6vw, 62px); }
.chapter { display: grid; grid-template-columns: 180px 1fr; gap: 42px; }
.chapter-label { position: sticky; top: 90px; height: max-content; color: var(--cinnabar); font: 12px/1.8 var(--mono); letter-spacing: .12em; }
.chapter-content p { margin: 0 0 18px; }
.chapter-content ul { padding-left: 1.2em; }
.keyline { display: grid; grid-template-columns: 100px 1fr; gap: 18px; padding: 17px 0; border-top: 1px solid var(--line); }
.keyline b { color: var(--green-deep); font-family: var(--serif); }

.timeline { position: relative; margin-top: 26px; }
.timeline::before { content: ""; position: absolute; left: 89px; top: 8px; bottom: 8px; width: 1px; background: var(--line); }
.timeline-item { display: grid; grid-template-columns: 70px 1fr; gap: 40px; position: relative; margin-bottom: 28px; }
.timeline-item::before { content: ""; position: absolute; left: 84px; top: 8px; width: 9px; height: 9px; border-radius: 50%; background: var(--cinnabar); }
.timeline-year { color: var(--cinnabar); font: 12px/1.6 var(--mono); text-align: right; }
.timeline-item p { margin: 4px 0 0; color: var(--muted); }

.concept-map { display: grid; grid-template-columns: repeat(4, 1fr); gap: 1px; border: 1px solid var(--green); background: var(--green); }
.concept-step { min-height: 180px; padding: 22px; background: var(--paper); }
.concept-step .num { color: var(--cinnabar); font: 12px var(--mono); }
.concept-step p { color: var(--muted); font-size: 14px; }

.lab { padding: 28px; border: 1px solid var(--ink); background: #fbf8f0; box-shadow: 7px 7px 0 var(--green-wash); }
.scenario-tabs { display: flex; flex-wrap: wrap; gap: 8px; margin: 20px 0; }
.scenario-tabs button { padding: 8px 13px; border: 1px solid var(--line); background: transparent; color: var(--muted); cursor: pointer; }
.scenario-tabs button.active { border-color: var(--green); background: var(--green); color: #fff; }
.chain { display: grid; grid-template-columns: repeat(4, 1fr); gap: 10px; }
.chain-item { min-height: 122px; padding: 16px; border-top: 3px solid var(--gold); background: var(--paper); }
.chain-item b { display: block; margin-bottom: 7px; color: var(--green-deep); }
.chain-item span { color: var(--muted); font-size: 13px; }
.lab-insight { margin-top: 18px; padding: 14px 17px; background: var(--green-wash); color: var(--green-deep); }

.book-cover { padding: 32px; border: 1px solid var(--ink); background: var(--green-deep); color: var(--paper); min-height: 360px; display: flex; flex-direction: column; justify-content: space-between; }
.book-cover .cover-title { font: 900 40px/1.25 var(--serif); }
.book-cover .cover-meta { font: 12px/1.7 var(--mono); letter-spacing: .1em; }
.argument { counter-reset: argument; }
.argument-item { position: relative; padding: 24px 24px 24px 70px; border-top: 1px solid var(--line); }
.argument-item::before { counter-increment: argument; content: "0" counter(argument); position: absolute; left: 14px; top: 24px; color: var(--cinnabar); font: 12px var(--mono); }
.argument-item p { color: var(--muted); }

.practice-list { counter-reset: practice; }
.practice { display: grid; grid-template-columns: 70px 1fr; gap: 20px; padding: 28px 0; border-top: 1px solid var(--line); }
.practice::before { counter-increment: practice; content: counter(practice, decimal-leading-zero); color: var(--cinnabar); font: 13px var(--mono); }
.timer { text-align: center; padding: 40px 24px; border: 1px solid var(--green); background: var(--green-wash); }
.timer-display { margin: 10px 0 20px; font: 700 52px/1 var(--mono); color: var(--green-deep); }
.timer button { min-width: 110px; padding: 10px 18px; border: 1px solid var(--green-deep); background: var(--green-deep); color: #fff; cursor: pointer; }
.timer button + button { margin-left: 8px; background: transparent; color: var(--green-deep); }

.footer { padding: 34px 0 48px; border-top: 1px solid var(--ink); }
.footer-inner { display: flex; justify-content: space-between; gap: 18px; color: var(--muted); font: 12px/1.7 var(--mono); }
.footer a { text-decoration: none; }
.footer a:hover { color: var(--cinnabar); }

@media (max-width: 820px) {
  .hero { min-height: auto; grid-template-columns: 1fr; padding-top: 58px; }
  .dharma-wheel { margin: 35px auto 70px; }
  .section-head, .chapter { grid-template-columns: 1fr; gap: 10px; }
  .chapter-label { position: static; }
  .cols-3, .cols-2 { grid-template-columns: 1fr; }
  .concept-map, .chain { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 560px) {
  .wrap { width: min(100% - 28px, 1080px); }
  .nav-inner { display: block; padding-top: 10px; }
  .nav-links { margin-top: 2px; }
  .nav-links a { padding: 10px 8px; }
  .concept-map, .chain { grid-template-columns: 1fr; }
  .keyline { grid-template-columns: 1fr; gap: 3px; }
  .footer-inner { display: block; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition: none !important; }
}