:root {
  --ink: #111820;
  --ink-soft: #47515c;
  --muted: #7a858d;
  --paper: #f4f2ec;
  --paper-deep: #e8e7df;
  --line: rgba(17, 24, 32, .14);
  --blue: #4167dd;
  --amber: #c17d29;
  --teal: #267f83;
  --white: #fff;
  --shadow: 0 22px 70px rgba(17, 24, 32, .12);
  --display: "Noto Serif SC", "Songti SC", SimSun, serif;
  --body: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  --mono: "IBM Plex Mono", "SFMono-Regular", Consolas, monospace;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; background: var(--paper); color: var(--ink); font-family: var(--body); line-height: 1.75; }
a { color: inherit; text-decoration: none; }
button, input { font: inherit; }
.site-shell { min-height: 100vh; overflow: hidden; }
.topbar { max-width: 1240px; margin: 0 auto; padding: 22px 32px; display: flex; align-items: center; justify-content: space-between; gap: 28px; }
.brand { display: inline-flex; align-items: center; gap: 11px; letter-spacing: .03em; }
.brand-mark { display: grid; place-items: center; width: 38px; height: 38px; background: var(--ink); color: #f0cf86; font: 700 12px/1 var(--mono); letter-spacing: .08em; }
.brand strong, .brand small { display: block; line-height: 1.15; }
.brand strong { font-size: 15px; }
.brand small { margin-top: 5px; color: var(--muted); font-size: 10px; letter-spacing: .12em; text-transform: uppercase; }
.topnav { display: flex; align-items: center; gap: 24px; color: var(--ink-soft); font-size: 13px; }
.topnav a { transition: color .2s ease; }
.topnav a:hover, .topnav a:focus-visible { color: var(--blue); }
.topnav .nav-cta { padding: 8px 13px; border: 1px solid var(--line); color: var(--ink); }
.kicker { margin: 0; color: var(--muted); font: 11px/1.3 var(--mono); letter-spacing: .12em; text-transform: uppercase; }
.kicker span { display: inline-block; width: 20px; height: 1px; margin: 0 8px 3px 0; background: var(--amber); }
.hero { max-width: 1240px; min-height: 620px; margin: 0 auto; padding: 78px 32px 88px; display: grid; grid-template-columns: 1.12fr .88fr; gap: 70px; align-items: center; }
.hero-copy { max-width: 620px; }
h1, h2, h3, p { margin-top: 0; }
h1, h2 { font-family: var(--display); font-weight: 600; letter-spacing: -.04em; line-height: 1.16; }
h1 { margin: 27px 0 25px; font-size: clamp(44px, 6vw, 78px); }
h1 em { color: var(--blue); font-style: normal; }
.hero-lead { max-width: 540px; color: var(--ink-soft); font-size: 16px; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 12px; margin: 34px 0 25px; }
.button { display: inline-flex; align-items: center; justify-content: center; min-height: 45px; padding: 0 17px; border: 1px solid var(--line); font-size: 13px; transition: transform .2s ease, box-shadow .2s ease, background .2s ease; }
.button:hover, .button:focus-visible { transform: translateY(-2px); box-shadow: 0 8px 20px rgba(17, 24, 32, .1); }
.button-primary { border-color: var(--blue); background: var(--blue); color: #fff; }
.button-quiet { background: rgba(255,255,255,.35); }
.hero-note { color: var(--muted); font: 11px/1.5 var(--mono); }
.status-dot { display: inline-block; width: 7px; height: 7px; margin-right: 7px; border-radius: 50%; background: #4baf83; box-shadow: 0 0 0 4px rgba(75,175,131,.13); }
.hero-art { position: relative; width: min(100%, 410px); justify-self: end; padding: 30px 0 12px 32px; }
.hero-art::before { content: ""; position: absolute; inset: 0 0 0 35px; border: 1px solid var(--line); background: var(--paper-deep); transform: rotate(3.5deg); }
.art-label { position: relative; z-index: 1; margin: 0 0 13px; color: var(--muted); font: 10px/1 var(--mono); letter-spacing: .14em; }
.cover-frame { position: relative; z-index: 1; width: 69%; margin-left: 15%; padding: 10px; background: #fff; box-shadow: var(--shadow); transform: rotate(-2deg); }
.cover-frame img { display: block; width: 100%; height: auto; }
.art-caption { position: relative; z-index: 2; display: flex; justify-content: space-between; align-items: baseline; margin: -12px 0 0 10%; padding: 13px 0 0; color: var(--ink); font-size: 12px; }
.art-caption span { color: var(--muted); font-size: 10px; }
.signal-strip { max-width: 1240px; margin: 0 auto; padding: 0 32px 56px; display: grid; grid-template-columns: repeat(3, 1fr); gap: 0; }
.signal-strip div { display: flex; align-items: center; gap: 15px; min-height: 72px; border-top: 1px solid var(--line); color: var(--ink-soft); font-size: 13px; }
.signal-strip div + div { padding-left: 23px; border-left: 1px solid var(--line); }
.signal-strip b { color: var(--blue); font: 12px var(--mono); }
.content-layout { max-width: 1240px; margin: 0 auto; padding: 64px 32px 40px; display: grid; grid-template-columns: 170px 1fr; gap: 80px; border-top: 1px solid var(--line); }
.index-rail { position: sticky; top: 24px; align-self: start; display: grid; gap: 11px; padding-top: 5px; }
.index-rail p { margin-bottom: 10px; color: var(--muted); font: 10px var(--mono); letter-spacing: .12em; text-transform: uppercase; }
.index-rail a { padding: 4px 0; border-left: 1px solid transparent; color: var(--muted); font-size: 12px; }
.index-rail a:hover, .index-rail a:focus-visible, .index-rail a.is-active { padding-left: 10px; border-left-color: var(--blue); color: var(--ink); }
.content-column { min-width: 0; }
.section-heading { max-width: 680px; margin-bottom: 52px; }
h2 { margin: 18px 0 16px; font-size: clamp(32px, 4vw, 50px); }
.section-heading > p:last-child, .section-intro { max-width: 630px; color: var(--ink-soft); font-size: 15px; }
.concept-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 14px; }
.concept-card { min-height: 232px; padding: 23px 20px 20px; border-top: 3px solid var(--blue); background: rgba(255,255,255,.54); }
.concept-card.accent-amber { border-top-color: var(--amber); }
.concept-card.accent-teal { border-top-color: var(--teal); }
.card-index { color: var(--muted); font: 11px var(--mono); }
.concept-card h3 { margin: 30px 0 10px; font-size: 18px; }
.concept-card p { color: var(--ink-soft); font-size: 13px; line-height: 1.7; }
.concept-card small { color: var(--muted); font: 10px var(--mono); }
.reading-section { position: relative; display: grid; grid-template-columns: 70px 1fr; gap: 22px; margin-top: 105px; padding-top: 30px; border-top: 1px solid var(--line); }
.section-number { color: var(--blue); font: 12px var(--mono); }
.reading-section h2 { font-size: clamp(29px, 3.6vw, 44px); }
.wear-table { margin: 31px 0 20px; border-top: 1px solid var(--line); font-size: 13px; }
.wear-row { display: grid; grid-template-columns: 1.25fr 1.25fr 1fr; gap: 12px; min-height: 43px; align-items: center; border-bottom: 1px solid var(--line); color: var(--ink-soft); }
.wear-head { color: var(--muted); font: 10px var(--mono); letter-spacing: .07em; text-transform: uppercase; }
.wear-row span:first-child { display: inline-flex; align-items: center; color: var(--ink); }
.wear-chip { width: 8px; height: 8px; margin-right: 9px; border-radius: 50%; background: #63a1ff; }
.wear-chip.mw { background: #73b0e8; }.wear-chip.ft { background: #c8a158; }.wear-chip.ww { background: #b87653; }.wear-chip.bs { background: #9f5b4b; }
.callout { padding: 13px 15px; border-left: 3px solid var(--amber); background: rgba(193,125,41,.09); color: var(--ink-soft); font-size: 13px; }
.callout strong { color: var(--amber); }
.rule-list { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; margin-top: 28px; }
.rule-list div { padding: 17px 15px; border: 1px solid var(--line); background: rgba(255,255,255,.35); }
.rule-list b, .rule-list span { display: block; }.rule-list b { margin-bottom: 8px; color: var(--teal); font-size: 14px; }.rule-list span { color: var(--ink-soft); font-size: 12px; line-height: 1.65; }
.safety-section { padding-bottom: 8px; }
.checklist { display: grid; gap: 0; margin-top: 30px; border-top: 1px solid var(--line); }
.checklist label { display: grid; grid-template-columns: 31px 20px 1fr; align-items: center; gap: 5px; min-height: 52px; border-bottom: 1px solid var(--line); color: var(--ink-soft); font-size: 13px; cursor: pointer; }
.checklist label > span { color: var(--blue); font: 10px var(--mono); }.checklist input { width: 14px; height: 14px; accent-color: var(--blue); }.checklist input:checked + * { color: var(--muted); }
.terms-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 9px; margin-top: 28px; }.terms-grid div { padding: 13px; background: rgba(255,255,255,.48); }.terms-grid b, .terms-grid span { display: block; }.terms-grid b { font: 12px var(--mono); color: var(--teal); }.terms-grid span { margin-top: 5px; color: var(--ink-soft); font-size: 12px; }
.closing-panel { max-width: 1176px; margin: 80px auto 72px; padding: 48px 52px; display: flex; justify-content: space-between; align-items: end; gap: 30px; background: var(--ink); color: #fff; }.closing-panel h2 { margin-bottom: 13px; color: #fff; font-size: clamp(30px, 4vw, 48px); }.closing-panel p:last-child { max-width: 540px; margin-bottom: 0; color: rgba(255,255,255,.68); font-size: 13px; }.closing-panel .button-primary { flex: 0 0 auto; border-color: #f0c971; background: #f0c971; color: var(--ink); }
.footer { max-width: 1240px; margin: 0 auto; padding: 22px 32px 38px; display: flex; justify-content: space-between; gap: 25px; border-top: 1px solid var(--line); color: var(--muted); font-size: 11px; }.footer div { display: flex; flex-wrap: wrap; gap: 18px; }.footer strong { color: var(--ink-soft); font-weight: 500; }.footer a:hover, .footer a:focus-visible { color: var(--blue); }
:focus-visible { outline: 3px solid rgba(65,103,221,.35); outline-offset: 3px; }
@media (max-width: 850px) { .topbar { padding: 18px 20px; }.topnav a:not(.nav-cta) { display: none; }.topnav .nav-cta { font-size: 11px; }.hero { min-height: auto; padding: 55px 20px 65px; grid-template-columns: 1fr; gap: 45px; }.hero-art { justify-self: center; }.signal-strip { padding: 0 20px 40px; }.signal-strip div { min-height: 62px; }.content-layout { padding: 47px 20px 20px; grid-template-columns: 1fr; gap: 35px; }.index-rail { position: static; display: flex; overflow-x: auto; gap: 16px; padding-bottom: 3px; white-space: nowrap; }.index-rail p { display: none; }.index-rail a { padding: 4px 0; }.index-rail a:hover, .index-rail a:focus-visible, .index-rail a.is-active { padding-left: 0; border-left: 0; border-bottom: 2px solid var(--blue); }.closing-panel { margin: 58px 20px 52px; padding: 35px 25px; display: block; }.closing-panel .button { margin-top: 25px; }.footer { margin: 0 20px; padding-left: 0; padding-right: 0; display: block; }.footer div + div { margin-top: 10px; } }
@media (max-width: 600px) { h1 { font-size: 43px; }.hero-lead { font-size: 14px; }.hero-art { padding-left: 20px; }.hero-art::before { left: 20px; }.cover-frame { width: 76%; margin-left: 10%; }.art-caption { margin-left: 6%; }.signal-strip { grid-template-columns: 1fr; }.signal-strip div + div { padding-left: 0; border-left: 0; }.signal-strip div { min-height: 47px; }.concept-grid, .rule-list, .terms-grid { grid-template-columns: 1fr; }.concept-card { min-height: auto; }.reading-section { grid-template-columns: 1fr; gap: 10px; margin-top: 72px; }.section-number { margin-bottom: 4px; }.wear-row { grid-template-columns: 1.2fr 1fr; }.wear-row span:nth-child(2) { display: none; }.checklist label { grid-template-columns: 25px 20px 1fr; font-size: 12px; }.hero-actions { align-items: stretch; flex-direction: column; }.hero-actions .button { width: 100%; }.footer div { gap: 10px; } }
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; }.button { transition: none; } }