:root {
  color-scheme: light;
  --background: 48 30% 96%;
  --foreground: 30 8% 10%;
  --card: 45 25% 93%;
  --muted-foreground: 40 6% 39%;
  --secondary: 45 22% 90%;
  --accent: 217 84% 46%;
  --accent-foreground: 0 0% 98%;
  --destructive: 4 70% 47%;
  --ok: 145 55% 32%;
  --border: 45 18% 85%;
  --font-mono: "JetBrains Mono", ui-monospace, "SF Mono", Menlo, monospace;
  --font-display: "Space Grotesk", system-ui, -apple-system, "Segoe UI", sans-serif;
}
@media (prefers-color-scheme: dark) {
  :root {
    color-scheme: dark;
    --background: 30 8% 8%;
    --foreground: 45 25% 90%;
    --card: 30 7% 11%;
    --muted-foreground: 40 6% 60%;
    --secondary: 30 6% 15%;
    --accent: 217 90% 62%;
    --accent-foreground: 30 8% 8%;
    --destructive: 4 75% 62%;
    --ok: 145 50% 55%;
    --border: 30 6% 20%;
  }
}
*, *::before, *::after { box-sizing: border-box; border-radius: 0 !important; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: hsl(var(--background));
  color: hsl(var(--foreground));
  font: 400 15.5px/1.55 var(--font-mono);
}
a { color: hsl(var(--accent)); text-underline-offset: 3px; }
.muted { color: hsl(var(--muted-foreground)); }
.small { font-size: 12.5px; }
.err { color: hsl(var(--destructive)); }
.grow { flex: 1; }
kbd { font: 500 11px var(--font-mono); border: 1px solid hsl(var(--border)); padding: 1px 5px; background: hsl(var(--card)); }

.top, .foot {
  display: flex; gap: 16px; align-items: center; flex-wrap: wrap;
  max-width: 1180px; margin: 0 auto; padding: 18px 24px;
}
.top { border-bottom: 1px solid hsl(var(--border)); }
.top .small { flex: 1; min-width: 200px; }
.foot { border-top: 1px solid hsl(var(--border)); margin-top: 48px; }
.brand { font: 700 18px var(--font-display); color: inherit; text-decoration: none; letter-spacing: -0.01em; }
.mark { color: hsl(var(--accent)); font-weight: 400; }

main { max-width: 1180px; margin: 0 auto; padding: 0 24px; }
section { padding: 36px 0 8px; }
.hero { padding-top: 44px; }
.hero-headline {
  font: 700 clamp(2.1rem, 6vw, 4.2rem)/1.04 var(--font-display);
  letter-spacing: -0.02em; margin: 0 0 28px;
}
.section-heading { font: 700 clamp(1.35rem, 2.2vw, 1.7rem) var(--font-display); letter-spacing: -0.01em; margin: 0 0 8px; }
.section-heading::before { content: "■ "; color: hsl(var(--accent)); font-weight: 400; }

.btn {
  font: 500 13px var(--font-mono); color: hsl(var(--foreground));
  background: hsl(var(--card)); border: 1px solid hsl(var(--border));
  padding: 8px 12px; cursor: pointer; transition: border-color .15s, background .15s;
}
.btn:hover { border-color: hsl(var(--foreground) / .5); }
.btn:active { background: hsl(var(--secondary)); }
:focus-visible { outline: 1px solid hsl(var(--accent)); outline-offset: 2px; }
.text-input {
  font: 500 14px var(--font-mono); color: hsl(var(--foreground));
  background: hsl(var(--card)); border: 1px solid hsl(var(--border));
  padding: 8px 10px; min-width: 0;
}
.text-input.big { font-size: 18px; padding: 10px 12px; flex: 1; max-width: 420px; }
.text-input:focus { outline: none; border-color: hsl(var(--accent)); }

.base-row { display: flex; gap: 8px; align-items: stretch; flex-wrap: wrap; }
.swatch-input { position: relative; width: 52px; flex: none; border: 1px solid hsl(var(--border)); cursor: pointer; }
.swatch-input.sm { width: 38px; }
.swatch-input input { position: absolute; inset: 0; opacity: 0; width: 100%; height: 100%; cursor: pointer; border: 0; padding: 0; }
.swatch-input .chip { display: block; width: 100%; height: 100%; min-height: 36px; }
.formats { display: flex; flex-wrap: wrap; gap: 6px; margin-top: 14px; }
.fmt {
  font: 400 12.5px var(--font-mono); color: hsl(var(--muted-foreground));
  background: none; border: 1px solid hsl(var(--border)); padding: 5px 9px; cursor: copy;
}
.fmt:hover { color: hsl(var(--foreground)); border-color: hsl(var(--foreground) / .5); }

.palettes { display: grid; gap: 10px; margin-top: 14px; }
.prow { display: grid; grid-template-columns: 120px 1fr; gap: 12px; align-items: center; }
.pname { font-size: 12.5px; color: hsl(var(--muted-foreground)); }
.pname b { display: block; color: hsl(var(--foreground)); font-weight: 500; }
.steps { display: grid; grid-template-columns: repeat(11, 1fr); gap: 0; border: 1px solid hsl(var(--border)); }
.sw {
  border: 0; padding: 22px 6px 6px; text-align: left; cursor: pointer;
  font: 500 11px/1.3 var(--font-mono); min-width: 0; overflow: hidden;
  transition: transform .12s;
}
.sw span { display: block; white-space: nowrap; overflow: hidden; text-overflow: clip; }
.sw .hx { opacity: .8; font-weight: 400; }
.sw:hover { transform: translateY(-2px); }
.sw:focus-visible { outline: 2px solid hsl(var(--foreground)); outline-offset: -2px; }
.sw.near span:first-child::before { content: "▸"; }
.sw { position: relative; }
.sw.is-fg::after, .sw.is-bg::after { content: ""; position: absolute; left: 0; right: 0; height: 3px; background: currentColor; }
.sw.is-fg::after { bottom: 0; }
.sw.is-bg::after { top: 0; }
.sw.is-fg.is-bg::after { top: 0; bottom: 0; width: 3px; height: auto; right: auto; }

.controls { display: flex; gap: 14px; align-items: center; flex-wrap: wrap; }
.controls input[type="range"] { width: 110px; accent-color: hsl(var(--accent)); }
.controls output { min-width: 4ch; color: hsl(var(--foreground)); }

.preview { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; margin-top: 14px; }
.pv { padding: 22px; display: grid; gap: 14px; align-content: start; }
.pv-card { padding: 18px; border: 1px solid; display: grid; gap: 10px; }
.pv-title { font: 700 22px/1.15 var(--font-display); letter-spacing: -0.01em; margin: 0; }
.pv-body { margin: 0; font-size: 14px; }
.pv-muted { margin: 0; font-size: 12.5px; }
.pv-row { display: flex; gap: 10px; align-items: center; flex-wrap: wrap; font-size: 13px; }
.pv-btn { padding: 8px 14px; font-weight: 600; border: 1px solid transparent; }
.pv-ghost { padding: 7px 13px; border: 1px solid; }
.pv-badge { padding: 2px 8px; font-size: 11.5px; font-weight: 500; }
.pv-meta { font-size: 11px; opacity: .85; }
@media (max-width: 760px) { .preview { grid-template-columns: 1fr; } }

.contrast { display: grid; grid-template-columns: minmax(280px, 380px) 1fr; gap: 16px; margin-top: 14px; }
.pair { border: 1px solid hsl(var(--border)); background: hsl(var(--card)); padding: 16px; display: grid; gap: 10px; align-content: start; }
.pair-row { display: grid; grid-template-columns: 92px 38px 1fr; gap: 8px; align-items: stretch; }
.pair-row .lbl { font-size: 12.5px; color: hsl(var(--muted-foreground)); align-self: center; }
.btn-row { display: flex; gap: 6px; flex-wrap: wrap; }
.btn:disabled { opacity: .45; cursor: default; }
.scores { border-top: 1px solid hsl(var(--border)); padding-top: 12px; }
.ratio { font: 700 56px/1 var(--font-display); letter-spacing: -0.03em; }
.grades { border-collapse: collapse; margin: 12px 0; font-size: 13px; width: 100%; }
.grades th { text-align: left; font-weight: 500; color: hsl(var(--muted-foreground)); padding: 3px 0; }
.grades td { padding: 3px 0; }
.pass { color: hsl(var(--ok)); font-weight: 600; }
.fail { color: hsl(var(--destructive)); }
.apca { font-size: 14px; }
.sample { border: 1px solid hsl(var(--border)); padding: 24px 28px; display: grid; gap: 10px; align-content: center; min-height: 300px; }
.sample p { margin: 0; }
.s-xl { font: 700 clamp(28px, 4vw, 44px)/1.1 var(--font-display); letter-spacing: -0.02em; }
.s-lg { font: 400 24px/1.3 var(--font-display); }
.s-md { font-size: 16px; max-width: 62ch; }
.s-sm { font-size: 12px; }
.s-ui { display: flex; gap: 12px; align-items: center; flex-wrap: wrap; margin-top: 4px; font-size: 14px; }
.s-btn { padding: 8px 14px; font-weight: 600; }
.s-outline { padding: 7px 13px; border: 1px solid currentColor; }
.sample a { color: inherit; text-decoration: underline; }

.matrix-head { display: flex; gap: 16px; align-items: center; justify-content: space-between; flex-wrap: wrap; }
.matrix-head p { margin: 0; flex: 1; min-width: 240px; }
.matrix-wrap { overflow-x: auto; margin-top: 12px; border: 1px solid hsl(var(--border)); }
.matrix { border-collapse: collapse; font-size: 11.5px; width: 100%; }
.matrix th { font-weight: 500; padding: 6px 4px; color: hsl(var(--muted-foreground)); background: hsl(var(--card)); white-space: nowrap; }
.matrix td { padding: 6px 4px; text-align: center; white-space: nowrap; cursor: pointer; min-width: 46px; }
.matrix td.aa { font-weight: 700; }
.matrix td.aal { font-weight: 400; }
.matrix td.no span { opacity: .4; }
.matrix td.self { cursor: default; }
.matrix td:hover { outline: 1px solid hsl(var(--foreground)); outline-offset: -1px; }
.name-input { width: 12ch; padding: 5px 7px; font-size: 12.5px; }
.recent { display: flex; flex-wrap: wrap; gap: 4px; margin-top: 10px; align-items: center; }
.recent:empty { display: none; }
.recent-chip { width: 22px; height: 22px; border: 1px solid hsl(var(--border)); padding: 0; cursor: pointer; }
.recent-chip:hover { border-color: hsl(var(--foreground)); }

.tabs { display: flex; gap: 6px; align-items: center; flex-wrap: wrap; margin-top: 14px; }
.tab { font: 500 13px var(--font-mono); color: hsl(var(--muted-foreground)); background: none; border: 1px solid transparent; padding: 7px 10px; cursor: pointer; }
.tab[aria-selected="true"] { color: hsl(var(--foreground)); border-color: hsl(var(--border)); background: hsl(var(--card)); }
.tab[aria-selected="true"]::before { content: "▸ "; color: hsl(var(--accent)); }
.check { display: inline-flex; gap: 6px; align-items: center; cursor: pointer; }
.check input { accent-color: hsl(var(--accent)); }
.export {
  margin: 10px 0 0; padding: 16px; border: 1px solid hsl(var(--border)); background: hsl(var(--card));
  font: 400 12.5px/1.6 var(--font-mono); max-height: 420px; overflow: auto; white-space: pre;
}
.svg-preview { margin-top: 10px; border: 1px solid hsl(var(--border)); padding: 10px; overflow-x: auto; background: hsl(var(--card)); }
.svg-preview svg { display: block; max-width: 100%; height: auto; }

.toast {
  position: fixed; left: 50%; bottom: 24px; transform: translate(-50%, 12px);
  background: hsl(var(--foreground)); color: hsl(var(--background));
  font: 500 13px var(--font-mono); padding: 8px 14px; opacity: 0; pointer-events: none;
  transition: opacity .18s, transform .18s;
}
.toast.show { opacity: 1; transform: translate(-50%, 0); }

@media (max-width: 760px) {
  .contrast { grid-template-columns: 1fr; }
  .prow { grid-template-columns: 1fr; gap: 4px; }
  .steps { grid-template-columns: repeat(6, 1fr); }
  .sw { padding-top: 16px; }
  .pname b { display: inline; margin-right: 8px; }
  main, .top, .foot { padding-left: 16px; padding-right: 16px; }
}
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { transition: none !important; animation: none !important; }
}