:root {
  --wood: #c4a574;
  --bench: #5a3a22;
  --acid: #e3b341;
  --fire: #c43a2a;
  --waste: #6b3a8a;
  --ink: #1c1612;
  --paper: #f3ead8;
  --paper-2: #fff8ea;
  --mute: #6a5a48;
  --line: rgba(90, 58, 34, 0.22);
  --serif: "Noto Serif SC", "Songti SC", serif;
  --sans: "Noto Sans SC", "PingFang SC", sans-serif;
  --mono: "IBM Plex Mono", ui-monospace, Menlo, monospace;
}
*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; }
section[id] { scroll-margin-top: 76px; }
body { margin: 0; color: var(--ink); background: var(--paper); font-family: var(--sans); font-size: 16px; line-height: 1.75; }
img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
.app-link { color: var(--fire); text-decoration: underline; text-underline-offset: 3px; }
button { font-family: inherit; cursor: pointer; }
code { font-family: var(--mono); font-size: 0.92em; background: rgba(227, 179, 65, 0.28); padding: 0.05em 0.35em; }
.grain {
  pointer-events: none; position: fixed; inset: 0; z-index: 5; opacity: 0.12;
  background-image: url("images/texture.webp"); background-size: 420px auto; mix-blend-mode: multiply;
}
.skip { position: absolute; left: -999px; }
.skip:focus { left: 12px; top: 12px; z-index: 80; background: var(--acid); color: var(--ink); padding: 8px 12px; }
.nav {
  position: sticky; top: 0; z-index: 40;
  display: flex; align-items: center; justify-content: space-between; gap: 16px;
  padding: 12px 28px; background: rgba(243, 234, 216, 0.94);
  backdrop-filter: blur(12px); border-bottom: 4px solid var(--acid);
}
.brand { display: flex; align-items: center; gap: 10px; font-family: var(--serif); font-weight: 700; }
.brand small { display: block; font-family: var(--mono); font-weight: 400; font-size: 10px; letter-spacing: 0.14em; color: var(--mute); }
.seal {
  width: 36px; height: 36px; display: grid; place-items: center;
  border: 2px solid var(--bench); background: var(--wood); color: var(--fire); font-family: var(--serif);
}
.nav-toggle { display: none; background: transparent; border: 1px solid var(--ink); color: var(--ink); padding: 6px 12px; }
.nav-links { display: flex; gap: 16px; font-size: 14px; }
.nav-links a { color: var(--mute); }
.nav-links a.is-active, .nav-links a:hover { color: var(--fire); }
.nav-links .live { color: #fff; background: var(--fire); padding: 6px 12px; }
.hero { position: relative; min-height: 86vh; display: grid; align-items: end; overflow: hidden; }
.hero > img { position: absolute; inset: 0; width: 100%; height: 100%; object-fit: cover; }
.hero::after {
  content: ""; position: absolute; inset: 0;
  background: linear-gradient(90deg, rgba(28, 22, 18, 0.88) 0%, rgba(28, 22, 18, 0.45) 58%, rgba(107, 58, 138, 0.4) 100%);
}
.hero-inner { position: relative; z-index: 2; padding: 10vh 8vw 8vh; max-width: 860px; color: var(--paper); }
.kicker, .vlabel { font-family: var(--mono); letter-spacing: 0.18em; font-size: 12px; color: var(--acid); margin: 0 0 12px; }
h1, h2, h3 { font-family: var(--serif); font-weight: 700; line-height: 1.08; margin: 0 0 16px; }
h1 { font-size: clamp(40px, 6.5vw, 78px); }
h2 { font-size: clamp(26px, 3.4vw, 42px); line-height: 1.16; }
h3 { font-size: 22px; line-height: 1.28; }
.lead { font-size: 17px; max-width: 42em; color: rgba(243, 234, 216, 0.92); }
.meta-row { display: flex; flex-wrap: wrap; gap: 8px; margin: 22px 0; }
.chip { border: 1px solid var(--acid); padding: 4px 10px; font-size: 12px; font-family: var(--mono); color: var(--acid); }
.hero-actions { display: flex; flex-wrap: wrap; gap: 12px; }
.btn { display: inline-flex; align-items: center; justify-content: center; padding: 10px 18px; border: 1px solid currentColor; font-size: 14px; }
.btn-fill { background: var(--fire); color: #fff; border-color: var(--fire); }
.btn-ghost { background: transparent; color: inherit; }
.wrap { width: min(1120px, calc(100% - 48px)); margin: 0 auto; padding: 84px 0; }
.section-head { display: grid; grid-template-columns: 140px 1fr; gap: 24px; margin-bottom: 40px; }
.section-head p:last-child { color: var(--mute); margin: 0; }
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }
.card { background: var(--paper-2); border: 1px solid var(--line); padding: 22px; min-height: 210px; box-shadow: 0 14px 30px rgba(28, 22, 18, 0.08); }
.stamp { display: inline-block; font-size: 11px; letter-spacing: 0.16em; color: var(--fire); border: 1px solid var(--fire); padding: 2px 8px; margin-bottom: 10px; font-family: var(--mono); }
.card ul, .io-grid ul, .rule-list { margin: 0; padding-left: 1.1em; }
.card li, .io-grid li, .rule-list li { margin: 0.35em 0; }
.alt { background: linear-gradient(180deg, #efe0c8 0%, var(--paper) 100%); }
.step { display: grid; grid-template-columns: 1fr 1fr; gap: 36px; align-items: center; margin-bottom: 68px; }
.step.reverse { direction: rtl; }
.step.reverse > * { direction: ltr; }
.num { font-family: var(--mono); font-size: 13px; letter-spacing: 0.2em; color: var(--waste); display: block; margin-bottom: 8px; }
figure { margin: 0; }
figure img { width: 100%; height: 320px; object-fit: cover; border-bottom: 8px solid var(--waste); }
figcaption { margin-top: 10px; font-size: 13px; color: var(--mute); font-style: italic; }
.gauge-demo { margin-top: 22px; padding: 16px; border: 1px dashed var(--fire); background: rgba(196, 58, 42, 0.08); }
.clock-label { margin: 0 0 12px; font-size: 12px; letter-spacing: 0.08em; color: var(--mute); font-family: var(--mono); }
.slider { display: grid; grid-template-columns: 72px 1fr 72px; gap: 10px; align-items: center; font-size: 13px; color: var(--mute); }
.slider input { width: 100%; accent-color: var(--fire); }
.slider span { font-family: var(--mono); color: var(--fire); }
.tri-state { margin: 12px 0 0; font-family: var(--mono); font-size: 13px; }
.tri-state.warn { color: var(--fire); }
.tri-state.ok { color: #3d7a4a; }
.bench-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
.bench { padding: 18px; background: var(--paper-2); border-left: 8px solid var(--acid); }
.bench h3 { font-size: 18px; margin-bottom: 8px; }
.bench p { margin: 0; color: var(--mute); font-size: 14px; }
.rule-list { font-size: 17px; max-width: 46em; }
.io-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 32px; }
footer { padding: 28px 40px 48px; font-size: 13px; color: var(--paper); background: var(--bench); }
@media (max-width: 900px) {
  .nav { flex-wrap: wrap; }
  .nav-toggle { display: inline-flex; margin-left: auto; position: relative; z-index: 60; background: var(--paper-2); }
  .nav-links {
    display: none; position: absolute; top: 100%; left: 0; right: 0;
    flex-direction: column; background: var(--paper-2); padding: 16px 24px 24px; z-index: 55;
  }
  .nav-links.open { display: flex; }
  .hero-inner { padding: 16vh 24px 48px; }
  .step, .step.reverse, .section-head, .grid-3, .bench-grid, .io-grid {
    grid-template-columns: 1fr; direction: ltr;
  }
  .wrap { width: calc(100% - 32px); padding: 56px 0; }
}