:root {
  --clay: #6b3a22;
  --amber: #c47a32;
  --paper: #f3ead8;
  --ink: #2a1c14;
  --mute: #6b5346;
  --peak: #b4232c;
  --ok: #3d6b46;
  --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: 72px; }

body {
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.7;
}

img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
.app-link { color: var(--clay); text-decoration: underline; text-underline-offset: 3px; }
button { font-family: inherit; cursor: pointer; }
code { font-family: var(--mono); background: rgba(196, 122, 50, 0.16); padding: 0.05em 0.35em; }

.brine-skin {
  pointer-events: none;
  position: fixed;
  inset: 0;
  z-index: 6;
  opacity: 0.16;
  background-image: url("images/texture.webp");
  background-size: 360px auto;
  mix-blend-mode: multiply;
}

.skip { position: absolute; left: -999px; }
.skip:focus { left: 10px; top: 10px; z-index: 80; background: var(--amber); padding: 8px; }

.vat-bar {
  position: sticky;
  top: 0;
  z-index: 50;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 10px 20px;
  background: rgba(243, 234, 216, 0.94);
  border-bottom: 4px solid var(--clay);
}
.brand { font-family: var(--serif); font-size: 24px; }
.brand small { display: block; font-family: var(--mono); font-size: 10px; letter-spacing: 0.16em; color: var(--mute); }
.nav-toggle { display: none; background: var(--clay); color: #fff; border: 0; padding: 8px 12px; }
.nav-links { display: flex; gap: 14px; align-items: center; font-size: 13px; }
.nav-links a { color: var(--mute); }
.nav-links a.is-active, .nav-links a:hover { color: var(--clay); }
.nav-links a.live { background: var(--clay); color: #fff; padding: 7px 12px; }

.hero {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 28px;
  align-items: center;
  padding: 48px 6vw 56px;
}
.kicker { font-family: var(--mono); letter-spacing: 0.16em; font-size: 11px; color: var(--clay); margin: 0 0 12px; }
h1, h2, h3 { font-family: var(--serif); margin: 0 0 14px; line-height: 1.12; }
h1 { font-size: clamp(34px, 5.2vw, 60px); }
h2 { font-size: clamp(24px, 3vw, 36px); }
h3 { font-size: 22px; }
.lead { max-width: 42em; }

.peak {
  margin: 16px 0;
  padding: 14px;
  background: rgba(255,255,255,0.5);
  border: 1px solid rgba(107, 58, 34, 0.2);
}
.peak .n { font-family: var(--mono); font-size: 28px; margin: 0 0 8px; color: var(--peak); }
.peak.ok .n, .peak.ok #peak-state { color: var(--ok); }
.peak label { display: flex; gap: 10px; align-items: center; font-family: var(--mono); font-size: 12px; }
.peak input { flex: 1; accent-color: var(--clay); }
#peak-state { margin: 8px 0 0; }

.cta { display: flex; flex-wrap: wrap; gap: 10px; }
.btn { display: inline-flex; align-items: center; padding: 10px 14px; border: 1px solid currentColor; }
.btn.fill { background: var(--clay); color: #fff; border-color: var(--clay); }
.btn.line { background: transparent; }

.hero figure { margin: 0; }
.hero figcaption, .pair figcaption { margin-top: 8px; font-size: 13px; color: var(--mute); }

.w { width: min(1080px, calc(100% - 40px)); margin: 0 auto; padding: 72px 0; }
.dark { background: #3a2416; color: var(--paper); }
.dark .kicker { color: var(--amber); }
.dark code { color: var(--paper); }

.tri { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; margin-top: 24px; }
.tri article, .pair article, .io > div {
  background: #fff8ee;
  border: 1px solid rgba(107, 58, 34, 0.16);
  padding: 16px;
}
.dark .tri article, .dark .pair article, .dark .io > div {
  background: rgba(243, 234, 216, 0.08);
  color: var(--paper);
}
.tri ul, .io ul, #rules ol { margin: 0; padding-left: 1.1em; }
.tri li, .io li, #rules li { margin: 0 0 6px; }

.pair { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; margin-top: 24px; }
.io { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; margin-top: 24px; }
.url { margin-top: 18px; }
.dark .app-link { color: var(--amber); }

footer {
  padding: 18px 22px 36px;
  font-family: var(--mono);
  font-size: 12px;
  color: var(--mute);
  border-top: 4px solid var(--clay);
}

@media (max-width: 900px) {
  .hero, .tri, .pair, .io { grid-template-columns: 1fr; }
  .nav-toggle { display: inline-block; }
  .nav-links {
    display: none;
    position: absolute;
    right: 10px;
    top: 52px;
    flex-direction: column;
    background: var(--paper);
    border: 1px solid var(--clay);
    padding: 10px;
    min-width: 180px;
  }
  .nav-links.open { display: flex; }
}