@import url('https://fonts.googleapis.com/css2?family=Cormorant+Garamond:wght@400;500;600&family=Noto+Sans+SC:wght@400;500;600&family=Noto+Serif+SC:wght@400;500;600&display=swap');

:root {
  color: #20201f;
  background: #f0eee6;
  font-family: 'Noto Sans SC', 'Microsoft YaHei', sans-serif;
  font-synthesis: none;
  --paper: #f0eee6;
  --paper-deep: #e4dfd3;
  --ink: #20201f;
  --muted: #6e6b66;
  --wine: #8c3028;
  --wine-soft: #e4c8c4;
  --wine-on-dark: #e0a39a;
  --clay: var(--wine);
  --navy: #243450;
  --line: rgba(32, 32, 31, .18);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; min-width: 320px; background: var(--paper); }
button, a { font: inherit; }
button { color: inherit; }
a { color: inherit; text-decoration: none; }
::selection { background: var(--clay); color: white; }

.topbar {
  height: 82px;
  padding: 0 clamp(24px, 5vw, 76px);
  border-bottom: 1px solid var(--line);
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  font-family: Consolas, monospace;
  font-size: 12px;
  letter-spacing: .08em;
  text-transform: uppercase;
}
.brand { display: inline-flex; align-items: center; gap: 13px; justify-self: start; }
.topbar .brand-name {
  color: var(--navy);
  font-family: 'Cormorant Garamond', Georgia, serif;
  font-size: 1.42rem;
  font-weight: 500;
  line-height: 1;
  letter-spacing: .005em;
  text-transform: none;
}
.lesson-index span { color: var(--clay); margin: 0 8px; }
.nav-pill { justify-self: end; border: 1px solid var(--ink); border-radius: 0; padding: 11px 17px; display: flex; gap: 20px; }
.nav-pill:hover { background: var(--navy); color: var(--paper); }

.hero { min-height: calc(100vh - 82px); padding: 72px clamp(24px, 6.4vw, 98px) 80px; display: grid; grid-template-columns: .88fr 1.12fr; gap: 5vw; align-items: center; }
.eyebrow { font-family: Consolas, monospace; color: var(--navy); letter-spacing: .11em; font-size: 13px; text-transform: uppercase; font-weight: 500; }
.hero h1, .section-heading h2, footer h2 { font-family: Georgia, 'Noto Serif SC', 'Songti SC', serif; }
.hero h1 { font-size: clamp(68px, 7.4vw, 118px); line-height: .95; letter-spacing: -.055em; margin: 30px 0 35px; font-weight: 600; }
.hero h1 em { color: var(--clay); font-style: italic; font-weight: 400; }
.hero h1 span { white-space: nowrap; }
.hero-intro { color: var(--muted); font-family: 'Noto Serif SC', serif; font-size: 18px; line-height: 1.9; max-width: 510px; }
.text-link { margin-top: 42px; display: inline-flex; gap: 60px; border-bottom: 1px solid var(--ink); padding-bottom: 8px; font-family: Consolas, monospace; font-size: 13px; text-transform: uppercase; }

.force-stage { min-height: 610px; position: relative; display: flex; align-items: center; justify-content: center; }
.pressure-block, .main-block { position: absolute; display: flex; align-items: center; justify-content: center; flex-direction: column; border-radius: 50%; z-index: 2; }
.pressure-block { width: clamp(210px, 22vw, 340px); height: clamp(210px, 22vw, 340px); background: var(--wine-soft); color: var(--wine); left: 3%; top: 12%; transform: rotate(-7deg); border: 1px solid rgba(140,48,40,.28); border-radius: 48% 52% 43% 57%; }
.main-block { width: clamp(180px, 19vw, 290px); height: clamp(270px, 28vw, 430px); background: var(--navy); color: white; right: 4%; bottom: 7%; border-radius: 47% 53% 48% 52%; transform: rotate(4deg); }
.pressure-block b, .main-block b { font: 600 clamp(88px, 10vw, 150px)/.8 Georgia, serif; }
.pressure-block small, .main-block small { font-family: Consolas, monospace; font-size: 12px; margin-top: 28px; letter-spacing: .09em; }
.yet-gate { z-index: 4; background: var(--paper); border: 2px solid var(--ink); width: 106px; height: 106px; border-radius: 18px; display: grid; place-items: center; font: 500 18px Consolas, monospace; transform: rotate(-5deg); box-shadow: 9px 9px 0 var(--ink); }
.force-lines { position: absolute; left: 35%; width: 31%; display: flex; justify-content: space-between; transform: rotate(2deg); }
.force-lines i { display: block; width: 2px; height: 260px; background: var(--ink); transform: rotate(68deg); opacity: .45; }
.stage-note { position: absolute; font: 11px Consolas, monospace; text-transform: uppercase; letter-spacing: .1em; }
.note-one { left: 0; bottom: 13%; transform: rotate(-90deg); }
.note-two { right: 1%; top: 9%; }
.scribble-arrow { position: absolute; width: 140px; right: 19%; top: 4%; fill: none; stroke: var(--ink); stroke-width: 2; stroke-linecap: round; }

.manifesto-strip { background: var(--navy); color: #f4f0e8; padding: 64px clamp(24px, 6.4vw, 98px); display: flex; justify-content: space-between; font: 500 clamp(34px, 4.7vw, 75px)/1.1 Georgia, 'Noto Serif SC', serif; }
.manifesto-strip p { margin: 0; }
.manifesto-strip i { color: var(--wine-on-dark); font-weight: 400; }

.section { padding: 130px clamp(24px, 6.4vw, 98px); }
.section-heading h2 { font-size: clamp(46px, 5vw, 76px); line-height: 1.16; letter-spacing: -.045em; margin: 25px 0 0; font-weight: 600; }
.model-section, .examples-section { display: grid; grid-template-columns: .72fr 1.28fr; gap: 8vw; }
.model-workbench { border-top: 1px solid var(--ink); }
.focus-tabs { display: flex; border-bottom: 1px solid var(--line); }
.focus-tabs button, .example-tabs button { background: transparent; border: 0; cursor: pointer; }
.focus-tabs button { padding: 18px 22px; font: 12px Consolas, monospace; text-transform: uppercase; color: var(--muted); border-bottom: 3px solid transparent; }
.focus-tabs button.active { color: var(--ink); border-color: var(--clay); }
.sentence-display { font: 600 clamp(32px, 3.6vw, 56px)/1.25 Georgia, serif; padding: 65px 0; min-height: 245px; transition: .3s ease; }
.sentence-display strong { color: var(--clay); font-style: italic; font-weight: 400; }
.sentence-part { transition: opacity .3s, filter .3s; }
.focus-b .part-a, .focus-a .part-b { opacity: .12; filter: blur(1px); }
.legend { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; border-top: 1px solid var(--line); padding: 24px 0; }
.legend button { display: flex; align-items: center; gap: 10px; border: 0; background: transparent; padding: 5px; cursor: pointer; text-align: left; }
.legend button b { font: 20px Georgia, serif; }
.dot { width: 12px; height: 12px; border-radius: 50%; }
.dot.clay { background: var(--clay); }.dot.ink { background: var(--navy); }
.insight-card { background: var(--paper-deep); padding: 28px 32px; display: grid; grid-template-columns: 38px 1fr; gap: 18px; border-radius: 2px; }
.insight-card p { margin: 0; font-family: 'Noto Serif SC', serif; line-height: 1.8; }
.mini-icon { font-size: 28px; }

.timeline-section { background: var(--navy); color: white; display: grid; grid-template-columns: .72fr 1.28fr; gap: 8vw; }
.section-heading.light .eyebrow { color: var(--wine-on-dark); }
.step-panel { display: grid; grid-template-columns: .8fr 1.2fr; border-top: 1px solid rgba(255,255,255,.45); }
.step-list { display: flex; flex-direction: column; border-right: 1px solid rgba(255,255,255,.2); }
.step-list button { flex: 1; text-align: left; padding: 24px; background: transparent; color: rgba(255,255,255,.55); border: 0; border-bottom: 1px solid rgba(255,255,255,.15); cursor: pointer; display: flex; gap: 18px; align-items: center; }
.step-list button span { font: 11px Consolas, monospace; }.step-list button b { font-size: 17px; }
.step-list button.active { color: white; background: rgba(255,255,255,.08); }.step-list button.active span { color: var(--wine-on-dark); }
.step-detail { min-height: 470px; padding: 35px 45px; position: relative; display: flex; flex-direction: column; justify-content: flex-end; }
.step-number { position: absolute; top: 25px; right: 35px; font: 70px Georgia, serif; opacity: .08; }
.mini-force { display: flex; align-items: center; gap: 12px; margin-bottom: auto; padding-top: 15px; }
.mini-force div { width: 74px; height: 74px; border: 1px solid rgba(255,255,255,.6); display: grid; place-items: center; border-radius: 50%; font: 36px Georgia, serif; }
.mini-force strong { color: var(--wine-on-dark); font: italic 24px Georgia, serif; }.mini-force i { opacity: .4; }
.step-0 div:first-child, .step-1 div:first-child { background: var(--wine-soft); border-color: var(--wine-soft); color: var(--wine); }.step-3 div:last-child { background: white; color: var(--navy); }
.step-detail h3 { font: 600 36px Georgia, 'Noto Serif SC', serif; margin: 0 0 15px; }.step-detail p { color: rgba(255,255,255,.65); font-family: 'Noto Serif SC', serif; line-height: 1.8; margin: 0 0 30px; }
.step-progress { height: 2px; background: rgba(255,255,255,.15); }.step-progress i { display: block; background: var(--wine-on-dark); height: 100%; transition: width .35s; }

.example-shell { display: grid; grid-template-columns: .45fr 1.55fr; gap: 35px; }
.example-tabs { display: flex; flex-direction: column; border-top: 1px solid var(--line); }
.example-tabs button { padding: 24px 10px; border-bottom: 1px solid var(--line); text-align: left; color: var(--muted); font-family: 'Noto Serif SC', serif; }
.example-tabs button span { display: block; font: 10px Consolas, monospace; margin-bottom: 10px; color: var(--clay); }
.example-tabs button.active { color: var(--ink); padding-left: 24px; position: relative; }.example-tabs button.active:before { content: '→'; position: absolute; left: 0; }
.example-card { background: #e6d6c8; padding: clamp(34px, 4vw, 62px); min-height: 520px; display: flex; flex-direction: column; justify-content: center; }
.example-card h3 { font: 600 clamp(28px, 3vw, 48px)/1.28 Georgia, serif; margin: 10px 0 30px; }
.example-label { font: 10px Consolas, monospace; letter-spacing: .12em; color: var(--navy); }
.yet-divider { display: flex; align-items: center; gap: 18px; color: var(--clay); font: italic 22px Georgia, serif; margin: 0 0 30px; }.yet-divider:before, .yet-divider:after { content: ''; height: 1px; background: rgba(32,32,31,.25); flex: 1; }
.example-note { border-top: 1px solid rgba(32,32,31,.2); padding-top: 24px; margin: 15px 0 0; color: var(--muted); font-family: 'Noto Serif SC', serif; line-height: 1.7; }

.voice-section { background: #dde7e1; padding: 115px clamp(24px, 11vw, 170px); color: var(--ink); position: relative; overflow: hidden; }
.voice-section:after { content: '“'; font: 500 420px Georgia, serif; position: absolute; right: 1%; top: -95px; opacity: .09; }
.voice-section .eyebrow { color: var(--navy); }
.voice-section blockquote { margin: 50px 0 60px; font: 600 clamp(42px, 6vw, 90px)/1.35 Georgia, 'Noto Serif SC', serif; letter-spacing: -.045em; position: relative; z-index: 1; }
.voice-section blockquote em { color: var(--wine); font-style: normal; }
.voice-copy { max-width: 960px; display: grid; grid-template-columns: 1fr 1fr; gap: 28px 54px; margin: -20px 0 42px; position: relative; z-index: 1; }
.voice-copy p { margin: 0; font-family: 'Noto Serif SC', serif; font-size: 17px; line-height: 1.9; color: #4f5853; }
.voice-tags { display: flex; gap: 10px; flex-wrap: wrap; }.voice-tags span { border: 1px solid rgba(37,31,28,.5); border-radius: 100px; padding: 9px 18px; font: 12px Consolas, monospace; }

.decision-section { display: grid; grid-template-columns: .72fr 1.28fr; gap: 8vw; }
.decision-path { margin: 0; padding: 0 12px; list-style: none; border: 1px solid var(--line); }
.decision-path li { display: grid; grid-template-columns: 48px minmax(0, 1fr); gap: 18px; padding: 24px 0; border-bottom: 1px solid var(--line); font-family: 'Noto Serif SC', serif; font-size: 18px; line-height: 1.7; min-width: 0; }
.decision-path li:last-child { border-bottom: 0; }
.decision-path li span { padding-left: 2px; color: var(--wine); font-family: Consolas, monospace; font-size: 12px; font-weight: 600; }
.decision-path span { color: var(--wine); font: 12px Consolas, monospace; padding-top: 6px; }

.practice-section { background: #e5e1d8; }
.practice-head { display: grid; grid-template-columns: 1fr 1fr; align-items: end; gap: 60px; margin-bottom: 80px; }
.practice-head > p { color: var(--muted); max-width: 420px; line-height: 1.8; font-family: 'Noto Serif SC', serif; }
.quiz-list { border-top: 1px solid var(--ink); }
fieldset { border: 0; border-bottom: 1px solid var(--line); padding: 50px 0; margin: 0; display: grid; grid-template-columns: 1.2fr .8fr; column-gap: 60px; }
legend { width: 100%; font: 600 clamp(23px, 2.2vw, 34px)/1.4 Georgia, serif; margin-bottom: 25px; }
legend span { font: 11px Consolas, monospace; color: var(--clay); margin-right: 25px; }
fieldset > p { color: var(--muted); font-family: 'Noto Serif SC', serif; margin: 0; }
.question-feedback { grid-column: 1 / -1; min-height: 28px; margin-top: 20px !important; padding-left: 18px; border-left: 2px solid var(--wine); color: var(--muted); font-size: 15px; line-height: 1.7; }
.question-feedback:empty { display: none; }
.options { display: flex; gap: 10px; grid-column: 2; grid-row: 1 / span 2; align-self: center; }
.options.stacked { flex-direction: column; }.options.three { justify-content: stretch; }.options.three button { flex: 1; text-transform: uppercase; }
.options button { background: transparent; border: 1px solid var(--ink); padding: 13px 18px; cursor: pointer; min-height: 48px; }
.options button:hover, .options button.selected { background: var(--navy); color: white; }
.options button.selected { box-shadow: inset 3px 0 0 var(--wine-on-dark); }
.quiz-progress { --progress: 0deg; position: relative; width: 44px; height: 44px; margin-top: 20px; border-radius: 50%; display: grid; place-items: center; background: conic-gradient(var(--navy) 0 var(--progress), var(--paper-deep) var(--progress) 360deg); color: var(--paper); font: 11px Consolas, monospace; }
.quiz-progress::before { content: ''; position: absolute; width: 34px; height: 34px; border-radius: 50%; background: var(--paper); }
.quiz-progress span { position: relative; z-index: 1; color: var(--navy); }
.quiz-submit { margin-top: 55px; display: grid; grid-template-columns: 1fr 1fr; gap: 50px; align-items: center; }
.quiz-submit > button { justify-self: start; background: var(--navy); color: white; border: 0; padding: 18px 24px; cursor: pointer; display: flex; gap: 45px; }.quiz-submit > button:disabled { opacity: .3; cursor: not-allowed; }
.result { border-left: 3px solid var(--clay); padding-left: 25px; }.result p { margin: 5px 0 0; color: var(--muted); }.result.correct { border-color: var(--navy); }

footer { background: var(--navy); color: var(--paper); padding: 85px clamp(24px, 6.4vw, 98px); display: flex; justify-content: space-between; align-items: flex-end; }
footer span { font: 11px Consolas, monospace; letter-spacing: .1em; color: var(--wine-on-dark); }
footer h2 { font-size: clamp(38px, 5vw, 78px); line-height: 1.18; margin: 25px 0 0; } footer h2 em { color: var(--wine-on-dark); font-style: normal; }

.knowledge-practice-divider { background: var(--paper); overflow: hidden; }
.knowledge-practice-divider img { display: block; width: 100%; height: auto; opacity: .72; }
.footer-links { display: flex; align-items: center; gap: 24px; }
.next-lesson { border-bottom: 1px solid rgba(255,255,255,.58); padding-bottom: 8px; font: 600 13px/1.3 Consolas, monospace; letter-spacing: .04em; }
.back-top { border: 1px solid rgba(255,255,255,.4); border-radius: 50%; width: 64px; height: 64px; display: grid; place-items: center; font-size: 26px; }

@media (max-width: 850px) {
  .topbar { grid-template-columns: 1fr auto; }.lesson-index { display: none; }.brand-name { font-size: .92rem; }
  .hero { grid-template-columns: 1fr; padding-top: 55px; }.hero h1 { font-size: clamp(64px, 17vw, 100px); }.force-stage { min-height: 500px; }
  .manifesto-strip { flex-direction: column; gap: 15px; }
  .model-section, .timeline-section, .examples-section, .decision-section { grid-template-columns: 1fr; gap: 60px; }
  .step-panel { grid-template-columns: 1fr; }.step-list { display: grid; grid-template-columns: 1fr 1fr; border-right: 0; }.step-list button { min-height: 76px; }
  .example-shell { grid-template-columns: 1fr; }.example-tabs { flex-direction: row; overflow-x: auto; }.example-tabs button { min-width: 130px; }
  .practice-head { grid-template-columns: 1fr; gap: 30px; }.practice-head > p { margin: 0; }
  fieldset { grid-template-columns: 1fr; }.options { grid-column: 1; grid-row: auto; margin-top: 30px; }.quiz-submit { grid-template-columns: 1fr; }
}

@media (max-width: 540px) {
  .topbar { height: 70px; }.nav-pill { padding: 10px 13px; gap: 8px; font-size: 12px; }
  .hero { min-height: auto; padding-bottom: 45px; }.hero h1 { font-size: clamp(54px, 14.5vw, 72px); line-height: 1.05; }.hero-intro { font-size: 18px; line-height: 1.85; }
  .force-stage { min-height: 390px; }.pressure-block { width: 200px; height: 200px; left: -3%; }.main-block { width: 165px; height: 255px; right: -2%; }.yet-gate { width: 78px; height: 78px; font-size: 14px; box-shadow: 6px 6px 0 var(--ink); }.force-lines { height: 180px; }.stage-note, .scribble-arrow { display: none; }
  .section { padding-top: 90px; padding-bottom: 90px; }.section-heading h2 { font-size: 42px; line-height: 1.3; }
  .eyebrow { font-size: 14px; }.text-link { font-size: 15px; }.legend { grid-template-columns: 1fr; }.legend button { font-size: 16px; line-height: 1.55; }.sentence-display { min-height: 220px; font-size: 30px; }
  .step-list { grid-template-columns: 1fr; }.step-list button b { font-size: 18px; }.step-detail { padding: 30px 24px; min-height: 430px; }.step-detail p { font-size: 17px; }
  .example-card { min-height: 460px; }.example-note { font-size: 17px; }.voice-section { padding-top: 85px; padding-bottom: 85px; }.voice-section blockquote { font-size: 38px; }.voice-copy { grid-template-columns: 1fr; gap: 18px; margin-top: -10px; }.voice-copy p { font-size: 17px; }.voice-tags span { font-size: 14px; }
  .decision-path li { font-size: 17px; }.practice-head > p, fieldset > p { font-size: 17px; }.question-feedback { font-size: 16px; }
  fieldset { padding: 40px 0; }.options { flex-direction: column; }.options button { font-size: 16px; }.options.three { flex-direction: row; }
  footer { align-items: center; } .footer-links { gap: 14px; } .next-lesson { font-size: 11px; white-space: nowrap; } .back-top { width: 50px; height: 50px; flex-shrink: 0; }
}

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

/* Minimal A/B model: a reading cue, not a second illustration. */
.ab-diagram { position: relative; width: min(100%, 520px); margin: 0 auto; padding: 34px 18px 22px; }
.force-stage { min-height: 360px; display: grid; place-items: center; }
.ab-node { display: flex; align-items: baseline; gap: 12px; position: absolute; z-index: 2; }
.ab-node span { display: grid; place-items: center; width: 72px; height: 72px; border-radius: 50%; font: 600 42px/1 Georgia, serif; }
.ab-node small { font: 12px Consolas, monospace; letter-spacing: .12em; white-space: nowrap; }
.ab-a { right: 0; top: 28px; color: var(--navy); flex-direction: row-reverse; }
.ab-a span { background: var(--navy); color: var(--paper); }
.ab-a small { color: var(--navy); }
.ab-b { left: 0; top: 28px; color: var(--wine); }
.ab-b span { border: 1px solid var(--wine); color: var(--wine); background: transparent; }
.ab-b small { color: var(--wine); }
.ab-connector { display: flex; align-items: center; justify-content: center; gap: 12px; padding-top: 62px; color: var(--wine); }
.ab-connector i { display: block; width: 82px; border-top: 1px solid currentColor; opacity: .55; }
.ab-connector strong { font: italic 25px Georgia, serif; }
.ab-caption { margin: 108px 0 0; text-align: center; color: var(--muted); font: 14px 'Noto Serif SC', serif; }
@media (max-width: 620px) {
  .force-stage { min-height: 250px; }
  .ab-diagram { padding: 22px 4px 12px; transform: scale(.92); transform-origin: center top; }
  .ab-node span { width: 58px; height: 58px; font-size: 34px; }
  .ab-node small { font-size: 10px; }
  .ab-a { right: 0; top: 18px; }
  .ab-b { left: 0; top: 18px; }
  .ab-connector { padding-top: 50px; }
  .ab-connector i { width: 52px; }
  .ab-caption { margin-top: 86px; font-size: 13px; }
}