:root {
  --paper: #f2eee4;
  --paper-deep: #e7e0d2;
  --ink: #171a16;
  --ink-soft: #4e554d;
  --rule: rgba(23, 26, 22, 0.19);
  --vermillion: #d9472d;
  --moss: #245c50;
  --white: #fbf8ef;
  --mono: "SFMono-Regular", "Cascadia Code", "Liberation Mono", Consolas, monospace;
  --sans: "Noto Sans SC", "Source Han Sans SC", "Microsoft YaHei", sans-serif;
  --serif: "Noto Serif SC", "Source Han Serif SC", "Songti SC", STSong, SimSun, serif;
  --pad: clamp(22px, 4.2vw, 68px);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--ink);
  background:
    linear-gradient(to right, transparent 0, transparent calc(100% - 1px), rgba(23,26,22,.035) 100%),
    var(--paper);
  background-size: 7.2vw 100%;
  font-family: var(--sans);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

a { color: inherit; }
img { display: block; max-width: 100%; }
p, h1, h2, h3 { margin: 0; }

.skip-link {
  position: fixed;
  z-index: 20;
  top: 10px;
  left: 10px;
  padding: 8px 12px;
  background: var(--ink);
  color: var(--white);
  text-decoration: none;
  transform: translateY(-160%);
}
.skip-link:focus { transform: translateY(0); }

.site-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 32px;
  padding: 22px var(--pad);
  border-bottom: 1px solid var(--ink);
}
.brand {
  display: flex;
  align-items: center;
  gap: 13px;
  text-decoration: none;
}
.brand-mark {
  display: grid;
  place-items: center;
  width: 64px;
  height: 40px;
  border: 1px solid var(--ink);
  background: var(--ink);
  color: var(--paper);
  font-family: var(--mono);
  font-size: 17px;
  font-weight: 700;
  letter-spacing: -0.08em;
}
.brand-copy {
  display: grid;
  font-size: 12px;
  font-weight: 700;
  line-height: 1.25;
  letter-spacing: 0.02em;
  text-transform: uppercase;
}
.brand-copy small {
  margin-top: 3px;
  color: var(--ink-soft);
  font-family: var(--mono);
  font-size: 9px;
  font-weight: 400;
  letter-spacing: 0.13em;
}
.nav {
  display: flex;
  align-items: center;
  gap: clamp(15px, 2vw, 30px);
  font-size: 13px;
}
.nav a {
  text-decoration: none;
  text-underline-offset: 5px;
}
.nav a:hover { text-decoration: underline; }
.nav-github { color: var(--ink-soft); }
.nav-open {
  padding: 8px 12px;
  border: 1px solid var(--ink);
  background: var(--paper);
  transition: background 160ms ease, color 160ms ease;
}
.nav-open:hover { background: var(--ink); color: var(--paper); text-decoration: none; }

.hero {
  display: grid;
  grid-template-columns: minmax(56px, 0.62fr) minmax(0, 6.5fr) minmax(260px, 2.4fr);
  min-height: 690px;
  border-bottom: 1px solid var(--ink);
}
.hero-margin {
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  padding: 28px 10px;
  border-right: 1px solid var(--rule);
  font-family: var(--mono);
  font-size: 9px;
  letter-spacing: 0.12em;
  writing-mode: vertical-rl;
  color: var(--ink-soft);
}
.hero-copy {
  align-self: center;
  padding: clamp(54px, 8vw, 110px) clamp(30px, 6vw, 100px) clamp(52px, 7vw, 94px) var(--pad);
}
.eyebrow, .section-index, .slip-kicker, .mode-tag {
  font-family: var(--mono);
  font-size: 10px;
  font-weight: 600;
  letter-spacing: 0.13em;
  text-transform: uppercase;
}
.eyebrow { display: flex; align-items: center; gap: 10px; color: var(--ink-soft); }
.eyebrow i {
  width: 7px;
  height: 7px;
  background: var(--vermillion);
  border-radius: 50%;
  box-shadow: 0 0 0 5px rgba(217, 71, 45, 0.12);
}
h1 {
  max-width: 940px;
  margin: 25px 0 27px;
  font-family: var(--serif);
  font-size: clamp(72px, 9.4vw, 136px);
  font-weight: 500;
  line-height: 0.91;
  letter-spacing: -0.075em;
  word-break: keep-all;
}
h1 em, h2 em {
  color: var(--vermillion);
  font-style: normal;
}
.lede {
  max-width: 690px;
  font-size: clamp(15px, 1.4vw, 19px);
  line-height: 1.85;
  color: var(--ink-soft);
}
.hero-actions {
  display: flex;
  align-items: center;
  gap: 30px;
  margin-top: 38px;
}
.button {
  display: inline-flex;
  align-items: center;
  gap: 30px;
  padding: 14px 19px;
  border: 1px solid var(--ink);
  background: var(--ink);
  color: var(--paper);
  font-size: 14px;
  font-weight: 600;
  text-decoration: none;
  transition: transform 160ms ease, background 160ms ease;
}
.button:hover { transform: translate(-3px, -3px); box-shadow: 3px 3px 0 var(--vermillion); }
.text-link {
  font-size: 13px;
  font-weight: 600;
  text-decoration: none;
  border-bottom: 1px solid var(--ink);
  padding-bottom: 3px;
  transition: color 160ms ease, border-color 160ms ease;
}
.text-link:hover { color: var(--vermillion); border-color: var(--vermillion); }

.route-slip {
  position: relative;
  align-self: center;
  margin: 35px clamp(20px, 3vw, 54px) 35px 0;
  padding: 24px 24px 26px;
  border: 1px solid var(--ink);
  background: rgba(251, 248, 239, 0.58);
  box-shadow: 8px 8px 0 var(--paper-deep);
}
.route-slip::before {
  content: "";
  position: absolute;
  top: -1px;
  left: 24px;
  width: 54px;
  border-top: 4px solid var(--vermillion);
}
.slip-kicker { color: var(--vermillion); }
.slip-line {
  margin-top: 22px;
  font-family: var(--serif);
  font-size: clamp(25px, 2.5vw, 38px);
  line-height: 1.18;
  letter-spacing: -0.05em;
}
.route-list {
  margin: 28px 0 0;
  padding: 0;
  list-style: none;
  border-top: 1px solid var(--rule);
}
.route-list li {
  display: grid;
  grid-template-columns: 28px 1fr;
  gap: 9px;
  padding: 11px 0;
  border-bottom: 1px solid var(--rule);
  font-size: 12px;
  line-height: 1.45;
}
.route-list span { color: var(--vermillion); font-family: var(--mono); font-size: 9px; padding-top: 3px; }
.slip-stamp {
  width: max-content;
  margin: 24px 0 0 auto;
  padding: 7px 5px;
  border: 2px solid var(--vermillion);
  color: var(--vermillion);
  font-family: var(--mono);
  font-size: 10px;
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: 0.14em;
  transform: rotate(-4deg);
  text-align: center;
}

.screen-section { padding: clamp(36px, 6vw, 84px) var(--pad) clamp(30px, 5vw, 68px); }
.screen-frame {
  position: relative;
  margin: 0;
  border: 1px solid var(--ink);
  background: var(--ink);
  box-shadow: 11px 11px 0 var(--paper-deep);
}
.screen-frame img { width: 100%; height: auto; filter: saturate(0.93) contrast(1.02); }
.screen-frame figcaption {
  display: flex;
  justify-content: space-between;
  gap: 20px;
  padding: 11px 16px;
  color: var(--paper);
  font-family: var(--mono);
  font-size: 9px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.protocol-strip {
  display: flex;
  gap: 0;
  padding: 0 var(--pad);
  border-top: 1px solid var(--ink);
  border-bottom: 1px solid var(--ink);
  overflow: hidden;
}
.protocol-strip p {
  flex: 1;
  min-width: max-content;
  padding: 15px clamp(15px, 2.8vw, 46px);
  border-right: 1px solid var(--rule);
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: 0.06em;
  text-align: center;
}
.protocol-strip p:first-child { border-left: 1px solid var(--rule); }
.protocol-strip p:nth-child(3) { color: var(--vermillion); }

.mechanism {
  display: grid;
  grid-template-columns: minmax(0, 1.12fr) minmax(300px, 0.88fr);
  gap: clamp(40px, 9vw, 150px);
  padding: clamp(80px, 12vw, 180px) var(--pad);
  border-bottom: 1px solid var(--ink);
}
.section-index { color: var(--vermillion); }
h2 {
  margin-top: 22px;
  font-family: var(--serif);
  font-size: clamp(44px, 6.3vw, 94px);
  font-weight: 500;
  line-height: 1.02;
  letter-spacing: -0.065em;
}
.mechanism-body { align-self: end; }
.intro {
  max-width: 510px;
  margin-bottom: 42px;
  font-size: 16px;
  line-height: 1.9;
  color: var(--ink-soft);
}
.state-line { margin: 0; padding: 0; list-style: none; border-top: 1px solid var(--ink); }
.state-line li {
  display: grid;
  grid-template-columns: 112px 1fr;
  gap: 18px;
  align-items: baseline;
  padding: 14px 0;
  border-bottom: 1px solid var(--rule);
}
.state-line b { font-family: var(--mono); font-size: 11px; font-weight: 600; letter-spacing: 0.04em; }
.state-line span { font-size: 13px; color: var(--ink-soft); }
.state-line li:nth-child(4) b, .state-line li:nth-child(5) b { color: var(--vermillion); }

.modes {
  display: grid;
  grid-template-columns: minmax(270px, 0.95fr) repeat(2, minmax(0, 1fr));
  padding: clamp(64px, 9vw, 130px) var(--pad);
  gap: 0;
  border-bottom: 1px solid var(--ink);
}
.mode-head { padding-right: clamp(26px, 4vw, 62px); }
.mode-head h2 { font-size: clamp(38px, 3.5vw, 54px); }
.mode {
  padding: 8px 0 0 clamp(24px, 3vw, 45px);
  border-left: 1px solid var(--rule);
}
.mode + .mode { margin-left: clamp(20px, 3vw, 45px); }
.mode-tag { color: var(--ink-soft); }
.mode h3 {
  max-width: 390px;
  margin: 28px 0 24px;
  font-family: var(--serif);
  font-size: clamp(26px, 2.5vw, 38px);
  font-weight: 500;
  line-height: 1.25;
  letter-spacing: -0.04em;
}
.mode p:not(.mode-tag):not(.mode-example) { max-width: 420px; font-size: 14px; line-height: 1.9; color: var(--ink-soft); }
.mode-example {
  margin-top: 34px;
  padding-top: 14px;
  border-top: 1px solid var(--rule);
  color: var(--ink);
  font-family: var(--mono);
  font-size: 10px;
  line-height: 1.7;
}
.mode-collective .mode-tag, .mode-collective h3 { color: var(--vermillion); }

.leader {
  display: grid;
  grid-template-columns: minmax(280px, 0.92fr) minmax(0, 1.08fr);
  gap: clamp(40px, 8vw, 130px);
  padding: clamp(80px, 12vw, 170px) var(--pad);
  background: var(--ink);
  color: var(--paper);
}
.leader .section-index { color: #e87055; }
.leader h2 { margin-top: 22px; font-size: clamp(47px, 6.4vw, 96px); }
.leader h2 em { color: #f0c95e; }
.leader-copy > p:not(.section-index) {
  max-width: 480px;
  margin: 32px 0 34px;
  color: rgba(242, 238, 228, 0.72);
  font-size: 15px;
  line-height: 1.9;
}
.text-link-light { border-color: rgba(242, 238, 228, 0.55); color: var(--paper); }
.text-link-light:hover { color: #f0c95e; border-color: #f0c95e; }
.leader-terminal {
  align-self: center;
  border: 1px solid rgba(242, 238, 228, 0.28);
  background: #0d100e;
  box-shadow: 10px 10px 0 rgba(240, 201, 94, 0.18);
}
.terminal-head {
  display: flex;
  justify-content: space-between;
  padding: 12px 15px;
  border-bottom: 1px solid rgba(242, 238, 228, 0.19);
  color: rgba(242, 238, 228, 0.45);
  font-family: var(--mono);
  font-size: 9px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}
.leader-terminal pre {
  margin: 0;
  padding: clamp(20px, 3vw, 38px);
  overflow-x: auto;
  color: #d9e2d4;
  font-family: var(--mono);
  font-size: clamp(10px, 1.02vw, 13px);
  line-height: 1.85;
}
.leader-terminal .dim { color: #788277; }
.leader-terminal > p {
  padding: 15px 18px;
  border-top: 1px solid rgba(242, 238, 228, 0.19);
  color: rgba(242, 238, 228, 0.54);
  font-size: 11px;
}

.audit {
  display: grid;
  grid-template-columns: minmax(280px, 1fr) minmax(0, 1fr);
  gap: clamp(40px, 8vw, 120px);
  padding: clamp(80px, 11vw, 160px) var(--pad);
  border-bottom: 1px solid var(--ink);
}
.audit h2 { font-size: clamp(38px, 4.3vw, 64px); }
.audit-list { border-top: 1px solid var(--ink); }
.audit-list div {
  display: grid;
  grid-template-columns: 70px 142px 1fr;
  gap: 12px;
  padding: 16px 0;
  border-bottom: 1px solid var(--rule);
  font-size: 12px;
}
.audit-list time { color: var(--ink-soft); font-family: var(--mono); font-size: 10px; }
.audit-list b { font-family: var(--mono); font-size: 10px; color: var(--moss); }
.audit-list span { color: var(--ink-soft); line-height: 1.6; }

.closing {
  padding: clamp(78px, 12vw, 180px) var(--pad) clamp(64px, 9vw, 130px);
  background: var(--vermillion);
  color: var(--paper);
}
.closing .section-index { color: rgba(251, 248, 239, 0.72); }
.closing h2 { max-width: 1070px; font-size: clamp(55px, 9vw, 145px); }
.closing-actions { display: flex; align-items: center; gap: 34px; margin-top: 46px; }
.button-invert { border-color: var(--ink); background: var(--paper); color: var(--ink); }
.button-invert:hover { box-shadow: 4px 4px 0 var(--ink); }
.closing .text-link-light { border-color: var(--ink); color: var(--ink); }
.closing .text-link-light:hover { color: var(--paper); border-color: var(--paper); }

.site-foot {
  display: flex;
  justify-content: space-between;
  gap: 26px;
  padding: 20px var(--pad);
  background: var(--ink);
  color: rgba(242, 238, 228, 0.63);
  font-family: var(--mono);
  font-size: 9px;
  letter-spacing: 0.05em;
}
.site-foot a { color: var(--paper); text-decoration: none; }
.site-foot a:hover { color: #f0c95e; }
.foot-links { display: flex; gap: 18px; }

@media (max-width: 1000px) {
  .nav a:not(.nav-github):not(.nav-open) { display: none; }
  .hero { grid-template-columns: 44px minmax(0, 1fr); }
  .hero-margin { grid-row: 1 / span 2; }
  .route-slip { margin: 0 var(--pad) 52px clamp(30px, 7vw, 70px); }
  .mechanism, .audit, .leader { grid-template-columns: 1fr; }
  .modes { grid-template-columns: 1fr; }
  .mode-head { padding-right: 0; margin-bottom: 44px; }
  .mode { padding: 28px 0 0; border-left: 0; border-top: 1px solid var(--ink); }
  .mode + .mode { margin: 30px 0 0; }
  .mechanism-body { padding-top: 10px; }
  .leader-terminal { margin-top: 8px; }
}

@media (max-width: 640px) {
  :root { --pad: 20px; }
  .site-head { padding-top: 16px; padding-bottom: 16px; }
  .brand-mark { width: 54px; }
  .brand-copy { display: none; }
  .nav { gap: 12px; font-size: 11px; }
  .nav-github { display: none; }
  .nav-open { padding: 7px 9px; }
  .hero { grid-template-columns: 30px minmax(0, 1fr); min-height: 0; }
  .hero-margin { padding: 18px 6px; font-size: 7px; }
  .hero-copy { padding: 52px 20px 42px 20px; }
  h1 { font-size: clamp(50px, 15.5vw, 62px); letter-spacing: -0.085em; }
  .lede { font-size: 14px; }
  .hero-actions { align-items: flex-start; flex-direction: column; gap: 22px; margin-top: 30px; }
  .route-slip { margin: 0 20px 38px 20px; padding: 22px 19px; }
  .screen-section { padding: 32px 14px 34px; }
  .screen-frame { box-shadow: 5px 5px 0 var(--paper-deep); }
  .screen-frame figcaption { display: block; line-height: 1.7; }
  .screen-frame figcaption span { display: block; }
  .protocol-strip { padding: 0; overflow-x: auto; }
  .protocol-strip p { padding: 12px 17px; }
  .mechanism, .modes, .audit { padding-top: 70px; padding-bottom: 70px; }
  h2 { font-size: clamp(40px, 12vw, 62px); }
  .state-line li { grid-template-columns: 96px 1fr; gap: 10px; }
  .leader { padding-top: 70px; padding-bottom: 70px; }
  .leader-terminal pre { font-size: 10px; }
  .audit-list div { grid-template-columns: 62px 1fr; }
  .audit-list span { grid-column: 1 / -1; }
  .closing { padding-top: 72px; }
  .closing h2 { font-size: clamp(50px, 15vw, 92px); }
  .closing-actions { align-items: flex-start; flex-direction: column; gap: 24px; margin-top: 34px; }
  .site-foot { display: grid; gap: 12px; }
}

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