:root {
  color-scheme: light;
  --paper: #fbfbfb;
  --ink: #0a0a0a;
  --muted: #5d5f60;
  --line: #d7d7d7;
  --soft: #f1f1f1;
  --blue: #0000ee;
  --selected: #eeeeff;
  --max: 1440px;
  --pad: clamp(18px, 3vw, 42px);
  --mono: ui-monospace, "SFMono-Regular", Consolas, "Liberation Mono", monospace;
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, sans-serif;
}
:root[data-theme="dark"] {
  color-scheme: dark;
  --paper: #101112;
  --ink: #f4f4ef;
  --muted: #aaaeae;
  --line: #3b3e40;
  --soft: #191b1d;
  --blue: #91a7ff;
  --selected: #1b2445;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    color-scheme: dark;
    --paper: #101112;
    --ink: #f4f4ef;
    --muted: #aaaeae;
    --line: #3b3e40;
    --soft: #191b1d;
    --blue: #91a7ff;
    --selected: #1b2445;
  }
}
* { box-sizing: border-box; }
html { background: var(--paper); scroll-behavior: smooth; -webkit-text-size-adjust: 100%; text-size-adjust: 100%; }
body { margin: 0; color: var(--ink); background: var(--paper); font: 16px/1.5 var(--sans); -webkit-font-smoothing: antialiased; }
a { color: var(--blue); text-underline-offset: 3px; }
a:visited { color: var(--blue); }
a:focus-visible, button:focus-visible { outline: 3px solid var(--blue); outline-offset: 3px; }
code, pre { font-family: var(--mono); }
.shell { width: min(100%, var(--max)); margin: 0 auto; border-inline: 1px solid var(--line); }
.mast { min-height: 64px; display: grid; grid-template-columns: minmax(220px, 4fr) minmax(0, 8fr); border-bottom: 1px solid var(--ink); }
.brand, .tools { padding: 11px var(--pad); display: flex; align-items: center; }
.brand { border-right: 1px solid var(--line); color: var(--ink); text-decoration: none; }
.brand:visited { color: var(--ink); }
.wordmark { font: 800 24px/1 var(--mono); letter-spacing: -2px; }
.wordmark i { color: var(--blue); font-style: normal; }
.tools { justify-content: space-between; gap: 18px; font: 12px/1.2 var(--mono); }
.tools nav { display: flex; align-items: center; gap: 18px; }
.tools a { color: var(--ink); font-weight: 700; text-decoration: none; }
.theme-toggle { padding: 7px 10px; border: 1px solid var(--line); background: var(--paper); color: var(--ink); font: inherit; cursor: pointer; }
.hero { display: grid; grid-template-columns: minmax(330px, 4fr) minmax(0, 8fr); min-height: 600px; border-bottom: 1px solid var(--ink); }
.hero-score, .hero-copy { padding: clamp(38px, 6vw, 88px) var(--pad); }
.hero-score { border-right: 1px solid var(--line); display: flex; flex-direction: column; justify-content: space-between; gap: 48px; }
.eyebrow { margin: 0; color: var(--muted); font: 12px/1.35 var(--mono); letter-spacing: .05em; text-transform: uppercase; }
.score { margin-top: 34px; font: 760 clamp(92px, 13vw, 190px)/.78 var(--sans); letter-spacing: -.09em; }
.score span { color: var(--blue); }
.hero-score p:last-child { max-width: 29ch; margin: 0; font-size: 18px; }
.hero-copy { display: flex; flex-direction: column; justify-content: center; }
h1 { max-width: 12ch; margin: 0 0 26px; font-size: clamp(52px, 7.4vw, 108px); line-height: .88; letter-spacing: -.067em; }
.lede { max-width: 54ch; margin: 0; color: var(--muted); font-size: clamp(19px, 2vw, 25px); line-height: 1.4; }
.result-strip { display: grid; grid-template-columns: repeat(4, 1fr); border-bottom: 1px solid var(--ink); }
.result { min-height: 150px; padding: 22px var(--pad); border-right: 1px solid var(--line); }
.result:last-child { border-right: 0; }
.result b { display: block; margin-bottom: 38px; color: var(--blue); font: 700 13px/1 var(--mono); }
.result span { color: var(--muted); }
.section { border-bottom: 1px solid var(--ink); }
.section-head { display: grid; grid-template-columns: 180px minmax(0, 1fr); border-bottom: 1px solid var(--line); }
.section-index, .section-title { padding: 24px var(--pad); }
.section-index { border-right: 1px solid var(--line); color: var(--muted); font: 12px/1.4 var(--mono); text-transform: uppercase; }
.section-title h2 { max-width: 18ch; margin: 0; font-size: clamp(38px, 5vw, 68px); line-height: .96; letter-spacing: -.05em; }
.section-title p { max-width: 67ch; margin: 16px 0 0; color: var(--muted); font-size: 18px; }
.matrix { width: 100%; border-collapse: collapse; }
.matrix th, .matrix td { padding: 17px var(--pad); border-right: 1px solid var(--line); border-bottom: 1px solid var(--line); text-align: left; }
.matrix tr:last-child td { border-bottom: 0; }
.matrix th:last-child, .matrix td:last-child { border-right: 0; }
.matrix th { color: var(--muted); font: 11px/1.3 var(--mono); text-transform: uppercase; }
.matrix td:first-child { font-weight: 700; }
.pass { color: var(--blue); font: 700 12px/1 var(--mono); }
.invariants { list-style: none; margin: 0; padding: 0; }
.invariant { display: grid; grid-template-columns: 70px minmax(210px, 1fr) minmax(0, 2fr); border-bottom: 1px solid var(--line); }
.invariant:last-child { border-bottom: 0; }
.invariant > * { min-width: 0; padding: 22px var(--pad); border-right: 1px solid var(--line); }
.invariant > *:last-child { border-right: 0; }
.invariant span { color: var(--blue); font: 700 12px/1.3 var(--mono); }
.invariant p { margin: 0; color: var(--muted); }
.method { display: grid; grid-template-columns: repeat(3, 1fr); }
.method article { min-height: 260px; padding: 28px var(--pad); border-right: 1px solid var(--line); }
.method article:last-child { border-right: 0; }
.method small { color: var(--blue); font: 12px/1 var(--mono); }
.method h3 { margin: 64px 0 10px; font-size: 24px; }
.method p { margin: 0; color: var(--muted); }
.boundary { display: grid; grid-template-columns: 1fr 1fr; }
.boundary > div { padding: clamp(30px, 5vw, 68px) var(--pad); }
.boundary > div:first-child { border-right: 1px solid var(--line); }
.boundary h3 { margin: 0 0 24px; font-size: 28px; }
.boundary ul { margin: 0; padding-left: 20px; }
.boundary li + li { margin-top: 12px; }
.boundary .does-not { background: var(--soft); }
.reproduce { display: grid; grid-template-columns: minmax(250px, 4fr) minmax(0, 8fr); }
.reproduce-copy, .command { padding: clamp(30px, 5vw, 60px) var(--pad); }
.reproduce-copy { border-right: 1px solid var(--line); }
.reproduce-copy h2 { margin: 0 0 16px; font-size: 38px; }
.reproduce-copy p { margin: 0; color: var(--muted); }
.command { margin: 0; background: var(--soft); overflow-x: auto; font-size: 14px; line-height: 1.8; white-space: pre; }
.evidence { display: grid; grid-template-columns: minmax(220px, 4fr) minmax(0, 8fr); }
.evidence > * { padding: 30px var(--pad); }
.evidence > div:first-child { border-right: 1px solid var(--line); }
.evidence p { margin: 0 0 12px; color: var(--muted); }
.digest { display: block; overflow-wrap: anywhere; font: 12px/1.6 var(--mono); }
.links { display: flex; flex-wrap: wrap; gap: 10px; }
.link { display: inline-flex; padding: 12px 14px; border: 1px solid var(--ink); color: var(--paper); background: var(--ink); font-weight: 700; text-decoration: none; }
.link:visited { color: var(--paper); }
.footer { padding: 34px var(--pad); display: flex; justify-content: space-between; gap: 30px; font: 12px/1.5 var(--mono); }
.footer p { margin: 0; }
@media (max-width: 820px) {
  .shell { border-inline: 0; }
  .mast, .hero, .section-head, .reproduce, .evidence { grid-template-columns: 1fr; }
  .brand, .hero-score, .reproduce-copy, .evidence > div:first-child { border-right: 0; border-bottom: 1px solid var(--line); }
  .tools { flex-wrap: wrap; overflow-x: auto; }
  .tools > strong, .tools nav { width: 100%; }
  .tools nav { justify-content: space-between; }
  .result-strip { grid-template-columns: 1fr 1fr; }
  .result:nth-child(2n) { border-right: 0; }
  .result:nth-child(-n+2) { border-bottom: 1px solid var(--line); }
  .section-head { grid-template-columns: 72px minmax(0, 1fr); }
  .matrix { display: block; overflow-x: auto; white-space: nowrap; }
  .invariant { grid-template-columns: 48px minmax(0, 1fr); }
  .invariant p { grid-column: 2; border-top: 1px solid var(--line); }
  .method, .boundary { grid-template-columns: 1fr; }
  .method article, .boundary > div:first-child { min-height: 0; border-right: 0; border-bottom: 1px solid var(--line); }
  .method h3 { margin-top: 32px; }
  .footer { flex-direction: column; }
}
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }