:root {
  --bg: #fbfaf7; --fg: #1d1d1b; --muted: #6b6a66; --line: #e4e1da;
  --card: #ffffff; --accent: #0f6e6e; --accent-soft: #e3f1f0;
  --warn: #9a5b00; --warn-soft: #fbf0dc; --fail: #c4572b; --pass: #2f6fb0;
  --mono: ui-monospace, "SF Mono", Menlo, monospace;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #141413; --fg: #ecebe6; --muted: #9c9a93; --line: #2c2b28;
    --card: #1c1c1a; --accent: #5cc2c2; --accent-soft: #15302f;
    --warn: #f0b45a; --warn-soft: #2e2516; --fail: #ee8a5e; --pass: #6fa8e0;
  }
}
* { box-sizing: border-box; }
body {
  margin: 0; background: var(--bg); color: var(--fg);
  font: 17px/1.65 -apple-system, BlinkMacSystemFont, "Inter", "Segoe UI", sans-serif;
}
main { max-width: 760px; margin: 0 auto; padding: 48px 16px 96px; }
a { color: var(--accent); }
h1 { font-size: 2.1rem; line-height: 1.2; margin: 0 0 8px; letter-spacing: -0.01em; }
h2 { font-size: 1.35rem; margin: 48px 0 12px; padding-top: 12px; border-top: 1px solid var(--line); }
h3 { font-size: 1.08rem; margin: 28px 0 8px; }
.eyebrow { font-size: .78rem; text-transform: uppercase; letter-spacing: .08em; color: var(--muted); margin-bottom: 6px; }
.lede { font-size: 1.12rem; color: var(--muted); margin: 0 0 24px; }
.meta { font-size: .88rem; color: var(--muted); }
nav.crumbs { font-size: .9rem; margin-bottom: 24px; }
.toc { background: var(--card); border: 1px solid var(--line); border-radius: 10px; padding: 14px 20px; font-size: .95rem; }
.toc ol { margin: 6px 0 0; padding-left: 20px; }
.card { background: var(--card); border: 1px solid var(--line); border-radius: 12px; padding: 18px 20px; margin: 16px 0; }
.card h3 { margin-top: 0; }
.tldr { background: var(--accent-soft); border: 0; }
.note { background: var(--warn-soft); border: 0; }
.note strong { color: var(--warn); }
blockquote { margin: 16px 0; padding: 12px 16px; border-left: 3px solid var(--accent); background: var(--card); font-size: .93rem; }
code { font-family: var(--mono); font-size: .88em; }
pre { overflow-x: auto; max-width: 100%; }
table { width: 100%; border-collapse: collapse; font-size: .93rem; margin: 12px 0; }
th, td { text-align: left; padding: 8px 10px; border-bottom: 1px solid var(--line); vertical-align: top; }
th { color: var(--muted); font-weight: 600; font-size: .82rem; text-transform: uppercase; letter-spacing: .04em; }
.table-wrap { overflow-x: auto; }
.num { font-variant-numeric: tabular-nums; }
.tag { display: inline-block; font-size: .75rem; padding: 2px 8px; border-radius: 99px; background: var(--accent-soft); color: var(--accent); margin-right: 4px; }
.module { display: block; text-decoration: none; color: inherit; }
.module:hover { border-color: var(--accent); }
.module .n { font-family: var(--mono); color: var(--muted); font-size: .85rem; }
details { border: 1px solid var(--line); border-radius: 10px; padding: 10px 16px; margin: 10px 0; background: var(--card); }
summary { cursor: pointer; font-weight: 600; }
.demo canvas { width: 100%; height: 220px; display: block; }
.demo input[type=range] { width: 100%; accent-color: var(--accent); }
.stats { display: grid; grid-template-columns: repeat(auto-fit, minmax(110px, 1fr)); gap: 10px; margin-top: 10px; }
.stat { border: 1px solid var(--line); border-radius: 8px; padding: 8px 10px; }
.stat .k { font-size: .75rem; color: var(--muted); text-transform: uppercase; letter-spacing: .05em; }
.stat .v { font-size: 1.3rem; font-weight: 600; font-variant-numeric: tabular-nums; }
.legend { font-size: .85rem; color: var(--muted); }
.legend b.f { color: var(--fail); } .legend b.p { color: var(--pass); }
footer { margin-top: 64px; font-size: .85rem; color: var(--muted); }
.pager { display: flex; justify-content: space-between; gap: 12px; margin-top: 48px; font-size: .92rem; }
.pager a { flex: 1; border: 1px solid var(--line); border-radius: 10px; padding: 10px 14px; text-decoration: none; background: var(--card); }
.pager a:hover { border-color: var(--accent); }
.pager .next { text-align: right; }
.pager small { display: block; color: var(--muted); font-size: .75rem; text-transform: uppercase; letter-spacing: .05em; }
.facts { display: grid; grid-template-columns: repeat(auto-fit, minmax(150px, 1fr)); gap: 10px; margin: 16px 0; }
.facts div { border: 1px solid var(--line); border-radius: 8px; padding: 8px 12px; font-size: .88rem; background: var(--card); }
.facts b { display: block; font-size: .72rem; color: var(--muted); text-transform: uppercase; letter-spacing: .05em; font-weight: 600; }
.unit { margin-top: 28px; }
.paper-row { display: grid; grid-template-columns: 2.4em 1fr; gap: 10px; align-items: start; padding: 10px 0; border-bottom: 1px solid var(--line); }
.paper-row .d { font-family: var(--mono); color: var(--muted); }
.paper-row label { display: flex; gap: 8px; align-items: baseline; }
.paper-row p { margin: 2px 0 0; font-size: .9rem; color: var(--muted); }
.robot { border-left: 3px solid var(--warn); padding-left: 12px; }
button { font: inherit; font-size: .9rem; padding: 6px 12px; border-radius: 8px; border: 1px solid var(--line); background: var(--card); color: var(--fg); cursor: pointer; }
button:hover { border-color: var(--accent); }
.kid { background: var(--card); border: 2px solid var(--accent); border-radius: 14px; padding: 18px 20px; margin: 20px 0; }
.kid h2 { border: 0; margin: 0 0 6px; padding: 0; font-size: 1.3rem; }
.kid .big { font-size: 1.15rem; font-weight: 600; margin: 6px 0 14px; }
.kid h3 { font-size: 1rem; margin: 18px 0 6px; color: var(--accent); }
.kid ol, .kid ul { padding-left: 22px; }
.kid dl { display: grid; grid-template-columns: max-content 1fr; gap: 6px 14px; margin: 0; }
.kid dt { font-weight: 600; }
.kid dd { margin: 0; }
.deeper { margin: 28px 0 0; padding: 10px 14px; border-radius: 10px; background: var(--accent-soft); font-size: .92rem; }
.track { display: inline-block; font-size: .72rem; font-weight: 700; letter-spacing: .06em; text-transform: uppercase; padding: 2px 8px; border-radius: 99px; vertical-align: middle; margin-right: 6px; border: 1px solid currentColor; }
.track.llm { color: var(--pass); }
.track.robo { color: var(--warn); }
.track.both { color: var(--accent); }
.eyebrow .track { font-size: .68rem; }
.paper-row .track { font-size: .62rem; padding: 1px 6px; margin-left: 4px; }