/* Docus — "road sign" theme.
   High-contrast black on white with signal yellow, road green and signal red.
   Octagon rule badges, dashed lane lines, bold sans. Graphic, not soft. */

:root {
  --paper: #ffffff;
  --panel: #f6f6f4;
  --ink: #141414;
  --muted: #585c60;
  --faint: #8f9498;
  --line: #dcdcd8;
  --line-2: #b9bcb8;
  --yellow: #f5c518;
  --yellow-deep: #b08a00;
  --green: #0f7a3d;
  --red: #d92b2b;
  --mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, monospace;
  --sans: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; background: var(--paper); color: var(--ink); font-family: var(--sans); font-size: 17px; line-height: 1.7; -webkit-font-smoothing: antialiased; }
.wrap { max-width: 1000px; margin: 0 auto; padding: 0 24px; }
a { color: var(--green); text-decoration: none; }
a:hover { color: var(--ink); }

/* ---------- header ---------- */
.site-head { background: var(--ink); }
.head-row { display: flex; align-items: center; justify-content: space-between; flex-wrap: wrap; gap: 14px; padding: 15px 24px; }
.brand { display: inline-flex; align-items: center; gap: 11px; font-weight: 800; letter-spacing: 0.2em; font-size: 18px; color: #fff; }
.brand:hover { color: var(--yellow); }
.brand-mark { display: inline-flex; align-items: center; justify-content: center; width: 26px; height: 26px; background: var(--yellow); color: var(--ink);
  font-weight: 900; font-size: 17px; clip-path: polygon(30% 0,70% 0,100% 30%,100% 70%,70% 100%,30% 100%,0 70%,0 30%); }
.nav { display: flex; flex-wrap: wrap; gap: 16px; font-size: 13px; font-weight: 700; letter-spacing: 0.05em; text-transform: uppercase; }
.nav a { color: #e9e9e6; }
.nav a:hover { color: var(--yellow); }
.roadline { height: 6px; background: repeating-linear-gradient(90deg, var(--yellow) 0 34px, var(--ink) 34px 52px); }

/* ---------- hero ---------- */
.hero { padding: 46px 0 22px; border-bottom: 3px solid var(--ink); }
.eyebrow { font-family: var(--mono); font-size: 12px; letter-spacing: 0.16em; text-transform: uppercase; color: var(--red); margin: 0 0 12px; font-weight: 700; }
.hero h1 { font-size: 38px; line-height: 1.1; margin: 0 0 14px; letter-spacing: -0.015em; }
.hero-sub { color: var(--muted); max-width: 48em; font-size: 18px; margin: 0; }

/* ---------- chapters ---------- */
.chapter { padding: 30px 0 6px; }
.chapter-head { display: flex; align-items: baseline; gap: 12px; border-bottom: 2px solid var(--line); padding-bottom: 8px; }
.chapter-head h2 { margin: 0; font-size: 24px; }
.chapter-head h2 a { color: var(--ink); }
.chapter-head h2 a:hover { color: var(--green); }
.chapter-count { margin-left: auto; font-family: var(--mono); font-size: 12px; text-transform: uppercase; letter-spacing: 0.06em; color: var(--faint); }
.chapter-blurb { color: var(--muted); margin: 10px 0 18px; max-width: 48em; }
.chapter-blurb.big { font-size: 18px; }
.chapter-intro { padding: 32px 0 8px; }
.chapter-intro h1 { font-size: 32px; margin: 6px 0 8px; }
.crumbs { font-family: var(--mono); font-size: 13px; color: var(--faint); padding: 28px 0 4px; }
.crumbs a { color: var(--green); }
.crumbs span { margin: 0 8px; color: var(--line-2); }

/* ---------- rule rows ---------- */
.rules { display: flex; flex-direction: column; gap: 0; padding-bottom: 8px; }
.rule { display: flex; align-items: center; gap: 15px; padding: 13px 6px; border-bottom: 2px solid var(--line); color: var(--ink); }
.rule:hover { background: var(--panel); border-bottom-color: var(--ink); }
.rule-sign { display: inline-flex; align-items: center; justify-content: center; flex: 0 0 auto; width: 40px; height: 40px; background: var(--ink); color: #fff;
  font-family: var(--mono); font-size: 13px; font-weight: 700; clip-path: polygon(30% 0,70% 0,100% 30%,100% 70%,70% 100%,30% 100%,0 70%,0 30%); }
.rule:hover .rule-sign { background: var(--yellow); color: var(--ink); }
.rule-main { display: flex; flex-direction: column; }
.rule-name { font-weight: 700; font-size: 17px; }
.rule-meta { font-family: var(--mono); font-size: 12px; color: var(--muted); }
.empty { color: var(--faint); font-style: italic; margin: 6px 0 18px; }

/* ---------- article ---------- */
.article { padding: 0 0 60px; }
.rule-head { display: flex; align-items: center; gap: 20px; padding: 10px 0 22px; border-bottom: 3px solid var(--ink); margin-bottom: 24px; }
.rule-shield { flex: 0 0 auto; display: inline-flex; align-items: center; justify-content: center; width: 78px; height: 78px; background: var(--yellow); color: var(--ink);
  font-weight: 900; font-size: 20px; letter-spacing: 0.02em; clip-path: polygon(30% 0,70% 0,100% 30%,100% 70%,70% 100%,30% 100%,0 70%,0 30%); }
.rule-kicker { font-family: var(--mono); font-size: 12px; letter-spacing: 0.12em; text-transform: uppercase; color: var(--red); margin: 0 0 6px; font-weight: 700; }
.rule-head h1 { font-size: 31px; line-height: 1.14; margin: 0; }
.rule-head .zh { color: var(--faint); font-size: 15px; margin: 6px 0 0; }

.specs { display: grid; grid-template-columns: repeat(auto-fit, minmax(175px, 1fr)); gap: 1px; background: var(--line-2); border: 2px solid var(--ink); margin: 0 0 34px; }
.spec { background: var(--paper); padding: 12px 14px; }
.spec dt { font-family: var(--mono); font-size: 10px; letter-spacing: 0.12em; text-transform: uppercase; color: var(--faint); margin: 0 0 4px; }
.spec dd { margin: 0; font-weight: 700; font-size: 15px; }

.sec { margin: 0 0 30px; }
.sec h2 { display: flex; align-items: baseline; gap: 12px; font-size: 21px; margin: 0 0 10px; }
.sec-no { display: inline-flex; align-items: center; justify-content: center; min-width: 34px; height: 26px; background: var(--ink); color: #fff; font-family: var(--mono); font-size: 13px; font-weight: 700; }
.sec p { margin: 0 0 14px; }
.sec p:last-child { margin-bottom: 0; }

.related-nav { border-top: 3px solid var(--ink); padding-top: 20px; margin-top: 40px; }
.related-nav h2 { font-size: 18px; margin: 0 0 14px; font-family: var(--mono); letter-spacing: 0.05em; text-transform: uppercase; }
.chips { display: flex; flex-wrap: wrap; gap: 9px; margin: 0; }
.chip { display: inline-block; padding: 7px 13px; border: 2px solid var(--ink); font-weight: 700; font-size: 14px; color: var(--ink); }
.chip:hover { background: var(--yellow); }
.chip-dim { border-color: var(--line); color: var(--faint); font-weight: 600; }
.chip-dim::after { content: " · soon"; font-family: var(--mono); font-size: 11px; }

/* ---------- legal / 404 ---------- */
.legal { padding: 40px 0 60px; max-width: 800px; }
.legal h1 { font-size: 31px; margin: 4px 0 10px; }
.legal h2 { font-size: 20px; margin: 26px 0 8px; }
.legal p, .legal li { color: #33383c; }
.legal ul { padding-left: 22px; }
.notfound { padding: 60px 0 90px; }
.notfound h1 { font-size: 34px; margin: 4px 0 8px; }
.back { margin: 26px 0 0; font-family: var(--mono); font-size: 14px; }

/* ---------- footer ---------- */
.site-foot { background: var(--ink); color: #dcdcd8; padding: 28px 0 36px; font-size: 14px; }
.site-foot p { margin: 0 0 10px; max-width: 58em; }
.site-foot a { color: var(--yellow); }
.site-foot a:hover { color: #fff; }
.foot-links { display: flex; flex-wrap: wrap; gap: 10px; }
.foot-links span { opacity: 0.5; }
.foot-fine { font-family: var(--mono); font-size: 12px; opacity: 0.6; }

@media (max-width: 640px) {
  .hero h1 { font-size: 30px; }
  .rule-head h1 { font-size: 25px; }
  .rule-shield { width: 60px; height: 60px; font-size: 16px; }
  .head-row { flex-direction: column; align-items: flex-start; }
}