:root {
  --paper: #f2f0e9;
  --paper-raised: #faf9f5;
  --ink: #111512;
  --ink-soft: #465049;
  --line: #c9cbc3;
  --line-strong: #9da49c;
  --evidence: #55705d;
  --evidence-dark: #34483b;
  --evidence-pale: #dfe7df;
  --warning: #a36a32;
  --warning-pale: #eee1d3;
  --serif: "Songti SC", "STSong", "SimSun", Georgia, serif;
  --sans: "Microsoft YaHei", "PingFang SC", "Noto Sans CJK SC", sans-serif;
  --mono: "SFMono-Regular", Consolas, "Liberation Mono", monospace;
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background:
    linear-gradient(rgba(17, 21, 18, 0.026) 1px, transparent 1px),
    var(--paper);
  background-size: 100% 32px;
  color: var(--ink);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.65;
}
button, a { -webkit-tap-highlight-color: transparent; }
button { font: inherit; }
a { color: inherit; }

.skip-link {
  position: fixed;
  top: 8px;
  left: 8px;
  z-index: 100;
  padding: 8px 12px;
  background: var(--ink);
  color: var(--paper);
  transform: translateY(-150%);
}
.skip-link:focus { transform: translateY(0); }

.site-header {
  position: relative;
  z-index: 2;
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: min(1440px, calc(100% - 64px));
  margin: 0 auto;
  padding: 24px 0;
  border-bottom: 1px solid var(--line);
}
.wordmark {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  font-weight: 700;
  text-decoration: none;
  letter-spacing: 0.06em;
}
.wordmark-mark {
  display: grid;
  width: 32px;
  height: 32px;
  place-items: center;
  border: 1px solid var(--ink);
  border-radius: 50%;
  font-family: var(--serif);
  font-weight: 400;
}
.site-nav { display: flex; align-items: center; gap: 24px; margin-left: auto; margin-right: 40px; }
.site-nav a { position: relative; color: var(--ink-soft); font-size: 13px; text-decoration: none; }
.site-nav a::after { position: absolute; right: 0; bottom: -5px; left: 0; height: 1px; background: var(--ink); content: ""; transform: scaleX(0); transform-origin: right; transition: transform 180ms var(--ease); }
.site-nav a:hover::after, .site-nav a:focus-visible::after { transform: scaleX(1); transform-origin: left; }
.header-status { display: flex; gap: 24px; font-family: var(--mono); font-size: 12px; letter-spacing: 0.04em; }
.header-status span { display: inline-flex; align-items: center; gap: 8px; }
.status-dot { width: 7px; height: 7px; border-radius: 50%; background: var(--evidence); box-shadow: 0 0 0 4px var(--evidence-pale); }
.header-status-secondary { color: var(--ink-soft); }

main, footer { width: min(1440px, calc(100% - 64px)); margin: 0 auto; }
.hero {
  min-height: 680px;
  display: grid;
  grid-template-columns: minmax(0, 1.45fr) minmax(340px, 0.72fr);
  gap: clamp(48px, 8vw, 128px);
  align-items: center;
  padding: 96px 0 112px;
}
.eyebrow {
  margin: 0 0 24px;
  color: var(--evidence-dark);
  font-family: var(--mono);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}
.maturity-badge { display: inline-flex; margin: 0 0 22px; border: 1px solid var(--warning); border-radius: 999px; padding: 5px 10px; background: var(--warning-pale); color: #70471f; font-family: var(--mono); font-size: 10px; letter-spacing: 0.06em; }
h1, h2, h3, p { text-wrap: pretty; }
h1 {
  max-width: 880px;
  margin: 0;
  font-family: var(--serif);
  font-size: clamp(52px, 7vw, 108px);
  font-weight: 400;
  letter-spacing: -0.065em;
  line-height: 0.98;
}
h1 em { color: var(--evidence); font-style: normal; }
.hero-lead { max-width: 710px; margin: 40px 0 0; color: var(--ink-soft); font-size: clamp(17px, 1.3vw, 21px); }
.hero-actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 40px; }
.button {
  min-height: 46px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--line-strong);
  border-radius: 999px;
  padding: 10px 20px;
  background: transparent;
  color: var(--ink);
  cursor: pointer;
  font-weight: 700;
  text-decoration: none;
  transition: transform 180ms var(--ease), background 180ms var(--ease), color 180ms var(--ease), border-color 180ms var(--ease);
}
.button:hover { border-color: var(--ink); transform: translateY(-2px); }
.button:active { transform: translateY(0); }
.button:focus-visible, .scenario-button:focus-visible { outline: 3px solid var(--warning); outline-offset: 3px; }
.button-primary { border-color: var(--ink); background: var(--ink); color: var(--paper); }
.button-primary:hover { background: var(--evidence-dark); border-color: var(--evidence-dark); }
.button:disabled { cursor: not-allowed; opacity: 0.35; transform: none; }

.proof-card { align-self: end; padding: 28px; border: 1px solid var(--line-strong); border-radius: 18px; background: rgba(250, 249, 245, 0.72); box-shadow: 0 28px 70px rgba(17, 21, 18, 0.08); backdrop-filter: blur(12px); }
.proof-card-top, .proof-card li { display: flex; justify-content: space-between; gap: 24px; }
.proof-card-top { font-family: var(--mono); font-size: 11px; letter-spacing: 0.08em; }
.proof-index { color: var(--ink-soft); }
blockquote { margin: 64px 0; font-family: var(--serif); font-size: clamp(32px, 3vw, 48px); line-height: 1.15; }
.proof-meter { height: 2px; background: var(--line); }
.proof-meter span { display: block; width: 74%; height: 100%; background: var(--evidence); }
.proof-card ul { list-style: none; margin: 24px 0 0; padding: 0; }
.proof-card li { padding: 13px 0; border-bottom: 1px solid var(--line); font-size: 13px; }
.proof-card li:last-child { border-bottom: 0; }
.proof-card strong { color: var(--evidence-dark); }

.demo-section { padding: 112px 0; border-top: 1px solid var(--line); }
.section-heading { display: grid; grid-template-columns: 1fr minmax(280px, 0.45fr); gap: 48px; align-items: end; margin-bottom: 48px; }
.section-heading h2 { max-width: 820px; margin: 0; font-family: var(--serif); font-size: clamp(38px, 5vw, 72px); font-weight: 400; letter-spacing: -0.045em; line-height: 1.05; }
.section-heading > p { margin: 0; color: var(--ink-soft); }
.workbench { display: grid; grid-template-columns: 340px minmax(0, 1fr); min-height: 640px; border: 1px solid var(--ink); border-radius: 18px; overflow: hidden; background: var(--paper-raised); box-shadow: 0 32px 90px rgba(17, 21, 18, 0.1); }
.scenario-list { padding: 16px; border-right: 1px solid var(--line-strong); background: var(--paper); }
.scenario-button { width: 100%; display: grid; grid-template-columns: 36px 1fr; gap: 12px; padding: 20px 14px; border: 0; border-bottom: 1px solid var(--line); background: transparent; color: var(--ink); cursor: pointer; text-align: left; transition: background 180ms var(--ease); }
.scenario-button:hover { background: rgba(85, 112, 93, 0.08); }
.scenario-button.is-active { background: var(--evidence-pale); }
.scenario-number { font-family: var(--mono); font-size: 11px; }
.scenario-button strong, .scenario-button small { display: block; }
.scenario-button strong { margin-bottom: 5px; }
.scenario-button small { color: var(--ink-soft); font-size: 12px; line-height: 1.5; }
.terminal { display: flex; min-width: 0; flex-direction: column; padding: clamp(24px, 4vw, 56px); }
.terminal-bar { display: flex; align-items: center; justify-content: space-between; gap: 24px; padding-bottom: 24px; border-bottom: 1px solid var(--line); }
.terminal-label, .task-request span, .result-kicker { display: block; margin-bottom: 6px; color: var(--ink-soft); font-family: var(--mono); font-size: 10px; letter-spacing: 0.12em; }
.terminal-state { border: 1px solid var(--line-strong); border-radius: 999px; padding: 5px 10px; font-family: var(--mono); font-size: 11px; white-space: nowrap; }
.terminal-state.is-running { border-color: var(--warning); color: var(--warning); background: var(--warning-pale); }
.terminal-state.is-complete { border-color: var(--evidence); color: var(--evidence-dark); background: var(--evidence-pale); }
.task-request { margin: 28px 0; padding: 20px 24px; border-left: 2px solid var(--evidence); background: rgba(85, 112, 93, 0.07); }
.task-request p { margin: 0; }
.trace-list { display: grid; gap: 8px; margin: 0; padding: 0; list-style: none; }
.trace-item { display: grid; grid-template-columns: 28px minmax(0, 1fr) auto; gap: 12px; align-items: center; min-height: 46px; padding: 8px 12px; border-bottom: 1px solid var(--line); opacity: 0.38; transition: opacity 320ms var(--ease), background 320ms var(--ease); }
.trace-item.is-current, .trace-item.is-done { opacity: 1; }
.trace-item.is-current { background: var(--warning-pale); }
.trace-item.is-done .trace-symbol { background: var(--evidence); color: var(--paper); }
.trace-symbol { display: grid; width: 24px; height: 24px; place-items: center; border: 1px solid var(--line-strong); border-radius: 50%; font-family: var(--mono); font-size: 10px; }
.trace-note { color: var(--ink-soft); font-size: 12px; }
.result-preview { margin-top: 24px; padding: 22px 24px; border: 1px solid var(--evidence); border-radius: 12px; background: var(--evidence-pale); animation: reveal 480ms var(--ease) both; }
.result-preview h3 { margin: 0 0 8px; font-family: var(--serif); font-size: 26px; font-weight: 400; }
.result-preview p { margin: 0; color: var(--ink-soft); }
.result-tags { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 16px; }
.result-tags span { border: 1px solid rgba(52, 72, 59, 0.35); border-radius: 999px; padding: 4px 9px; font-family: var(--mono); font-size: 10px; }
.terminal-actions { display: flex; flex-wrap: wrap; gap: 12px; align-items: center; margin-top: auto; padding-top: 32px; }
.terminal-actions > span { margin-left: auto; color: var(--ink-soft); font-size: 12px; }

.section-heading-top { align-items: start; }
.capabilities-section, .workflow-section, .rules-section { padding: 112px 0; border-top: 1px solid var(--line); }
.capability-grid { display: grid; grid-template-columns: repeat(2, 1fr); border-top: 1px solid var(--line-strong); border-left: 1px solid var(--line-strong); }
.capability-card { min-height: 300px; display: flex; flex-direction: column; padding: 32px; border-right: 1px solid var(--line-strong); border-bottom: 1px solid var(--line-strong); }
.capability-card-wide { grid-column: span 2; min-height: 380px; }
.capability-index, .phase-label { font-family: var(--mono); font-size: 10px; letter-spacing: 0.1em; }
.capability-card h3 { max-width: 480px; margin: auto 0 16px; font-family: var(--serif); font-size: clamp(30px, 3vw, 44px); font-weight: 400; line-height: 1.1; }
.capability-card p { max-width: 600px; margin: 0; color: var(--ink-soft); }
.input-orbit { display: grid; grid-template-columns: repeat(6, 1fr); gap: 8px; margin: auto 0 36px; }
.input-orbit span { display: grid; aspect-ratio: 1; place-items: center; border: 1px solid var(--line-strong); border-radius: 50%; font-family: var(--serif); font-size: clamp(22px, 3vw, 42px); transition: background 180ms var(--ease), color 180ms var(--ease), transform 180ms var(--ease); }
.input-orbit span:hover { background: var(--evidence-dark); color: var(--paper); transform: translateY(-5px); }

.layers-section { display: grid; grid-template-columns: minmax(300px, 0.75fr) minmax(0, 1.25fr); gap: clamp(48px, 8vw, 128px); padding: 112px 0; border-top: 1px solid var(--line); }
.layers-intro h2, .rules-lead h2, .boundaries-section h2, .maturity-section h2, .closing-section h2 { margin: 0; font-family: var(--serif); font-size: clamp(42px, 5vw, 72px); font-weight: 400; letter-spacing: -0.045em; line-height: 1.05; }
.layers-intro > p:last-child { max-width: 480px; margin-top: 28px; color: var(--ink-soft); }
.layer-stack { margin: 0; padding: 0; list-style: none; }
.layer-stack li { display: grid; grid-template-columns: 46px minmax(0, 1fr) auto; gap: 16px; align-items: center; min-height: 110px; padding: 18px 20px; border: 1px solid var(--line-strong); border-bottom: 0; background: var(--paper-raised); transition: transform 180ms var(--ease); }
.layer-stack li:first-child { border-radius: 12px 12px 0 0; }
.layer-stack li:last-child { border-bottom: 1px solid var(--line-strong); border-radius: 0 0 12px 12px; }
.layer-stack li:hover { position: relative; z-index: 1; transform: translateX(-8px); }
.layer-number { font-family: var(--mono); font-size: 11px; }
.layer-stack strong, .layer-stack small { display: block; }
.layer-stack strong { font-family: var(--serif); font-size: 24px; font-weight: 400; }
.layer-stack small { margin-top: 4px; color: var(--ink-soft); }
.layer-stack b { color: var(--evidence-dark); font-size: 12px; }

.phase-grid { display: grid; grid-template-columns: repeat(4, 1fr); border-top: 1px solid var(--ink); border-bottom: 1px solid var(--ink); }
.phase-grid li { min-height: 390px; display: flex; flex-direction: column; padding: 28px; border-right: 1px solid var(--line-strong); }
.phase-grid li:last-child { border-right: 0; }
.phase-grid h3 { margin: auto 0 18px; font-family: var(--serif); font-size: 34px; font-weight: 400; }
.phase-grid p { margin: 0; color: var(--ink-soft); }
.phase-grid small { margin-top: 32px; color: var(--evidence-dark); font-family: var(--mono); font-size: 10px; }

.rules-section { display: grid; grid-template-columns: minmax(260px, 0.65fr) minmax(0, 1.35fr); gap: clamp(48px, 8vw, 128px); }
.rule-list { border-top: 1px solid var(--ink); }
.rule-list article { display: grid; grid-template-columns: 44px minmax(180px, 0.55fr) minmax(240px, 1fr); gap: 20px; align-items: baseline; padding: 24px 0; border-bottom: 1px solid var(--line-strong); }
.rule-list span { font-family: var(--mono); font-size: 10px; }
.rule-list h3 { margin: 0; font-family: var(--serif); font-size: 26px; font-weight: 400; }
.rule-list p { margin: 0; color: var(--ink-soft); }

.boundaries-section { display: grid; grid-template-columns: minmax(0, 1.25fr) minmax(340px, 0.75fr); gap: clamp(48px, 8vw, 120px); padding: 112px 0; border-top: 1px solid var(--line); }
.boundary-main > p:not(.eyebrow) { max-width: 650px; color: var(--ink-soft); }
.boundary-list { margin: 48px 0 0; padding: 0; list-style: none; border-top: 1px solid var(--ink); }
.boundary-list li { display: grid; grid-template-columns: 130px 1fr; gap: 20px; padding: 18px 0; border-bottom: 1px solid var(--line); }
.boundary-list span { color: var(--ink-soft); font-family: var(--mono); font-size: 11px; }
.boundary-list strong { font-weight: 500; }
.public-safety-card { align-self: start; padding: 32px; border-radius: 18px; background: var(--evidence-dark); color: var(--paper); box-shadow: 0 30px 70px rgba(17, 21, 18, 0.14); }
.safety-signal { display: flex; align-items: center; gap: 10px; font-family: var(--mono); font-size: 10px; letter-spacing: 0.08em; }
.safety-signal i { width: 8px; height: 8px; border-radius: 50%; background: #b7d0bc; box-shadow: 0 0 0 5px rgba(183, 208, 188, 0.16); }
.public-safety-card h3 { margin: 72px 0 48px; font-family: var(--serif); font-size: 38px; font-weight: 400; line-height: 1.15; }
.public-safety-card dl { margin: 0; }
.public-safety-card dl div { display: flex; justify-content: space-between; gap: 20px; padding: 13px 0; border-bottom: 1px solid rgba(242, 240, 233, 0.2); }
.public-safety-card dt, .public-safety-card dd { margin: 0; font-size: 12px; }
.public-safety-card dt { opacity: 0.66; }

.maturity-section { display: grid; grid-template-columns: minmax(0, 1.1fr) minmax(320px, 0.9fr); gap: clamp(48px, 8vw, 120px); padding: 112px 0; border-top: 1px solid var(--warning); background: linear-gradient(90deg, var(--warning-pale), transparent 68%); }
.maturity-copy { align-self: end; }
.maturity-copy p { color: var(--ink-soft); }
.maturity-copy span { display: block; margin-top: 32px; color: var(--warning); font-family: var(--mono); font-size: 10px; letter-spacing: 0.1em; }
.closing-section { display: grid; place-items: center; min-height: 680px; padding: 112px 24px; border-top: 1px solid var(--line); text-align: center; }
.closing-section h2 { max-width: 900px; font-size: clamp(56px, 8vw, 112px); }
.closing-section > p:not(.eyebrow) { max-width: 650px; margin: 32px auto; color: var(--ink-soft); font-size: 18px; }
.closing-section .button { min-width: 160px; }
footer { display: flex; justify-content: space-between; gap: 24px; padding: 32px 0 48px; color: var(--ink-soft); font-family: var(--mono); font-size: 11px; }

@keyframes reveal { from { opacity: 0; transform: translateY(10px); } to { opacity: 1; transform: translateY(0); } }

@media (max-width: 980px) {
  .site-nav { display: none; }
  .hero { grid-template-columns: 1fr; padding-top: 72px; }
  .proof-card { max-width: 620px; align-self: auto; }
  .workbench { grid-template-columns: 1fr; }
  .scenario-list { display: grid; grid-template-columns: repeat(3, 1fr); padding: 0; border-right: 0; border-bottom: 1px solid var(--line-strong); }
  .scenario-button { grid-template-columns: 1fr; border-right: 1px solid var(--line); border-bottom: 0; }
  .scenario-button:last-child { border-right: 0; }
  .phase-grid { grid-template-columns: repeat(2, 1fr); }
  .phase-grid li:nth-child(2) { border-right: 0; }
  .phase-grid li:nth-child(-n + 2) { border-bottom: 1px solid var(--line-strong); }
  .layers-section, .rules-section, .boundaries-section, .maturity-section { grid-template-columns: 1fr; }
}

@media (max-width: 720px) {
  .site-header, main, footer { width: min(100% - 32px, 1440px); }
  .site-header { align-items: flex-start; }
  .header-status { flex-direction: column; gap: 2px; align-items: flex-end; }
  .hero { min-height: auto; gap: 56px; padding: 64px 0 80px; }
  h1 { font-size: clamp(48px, 15vw, 72px); }
  .hero-lead { margin-top: 28px; }
  .section-heading { grid-template-columns: 1fr; gap: 20px; }
  .demo-section { padding: 80px 0; }
  .scenario-list { grid-template-columns: 1fr; }
  .scenario-button { grid-template-columns: 34px 1fr; border-right: 0; border-bottom: 1px solid var(--line); }
  .terminal { padding: 24px 18px; }
  .trace-item { grid-template-columns: 28px 1fr; }
  .trace-note { grid-column: 2; }
  .terminal-actions > span { width: 100%; margin-left: 0; }
  .placeholder-section { grid-template-columns: 1fr; }
  .capabilities-section, .workflow-section, .rules-section, .layers-section, .boundaries-section, .maturity-section { padding: 80px 0; }
  .capability-grid { grid-template-columns: 1fr; }
  .capability-card-wide { grid-column: auto; }
  .capability-card { min-height: 260px; padding: 24px; }
  .input-orbit { grid-template-columns: repeat(3, 1fr); gap: 10px; margin: 48px 0; }
  .input-orbit span { font-size: 24px; }
  .layer-stack li { grid-template-columns: 40px 1fr; }
  .layer-stack b { grid-column: 2; }
  .phase-grid { grid-template-columns: 1fr; }
  .phase-grid li { min-height: 300px; border-right: 0; border-bottom: 1px solid var(--line-strong); }
  .phase-grid li:last-child { border-bottom: 0; }
  .rule-list article { grid-template-columns: 36px 1fr; }
  .rule-list p { grid-column: 2; }
  .boundary-list li { grid-template-columns: 1fr; gap: 6px; }
  .public-safety-card { padding: 28px 24px; }
  .closing-section { min-height: 580px; padding-right: 0; padding-left: 0; }
  footer { flex-direction: column; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation-duration: 0.01ms !important; animation-iteration-count: 1 !important; transition-duration: 0.01ms !important; }
}