/* Amber Quant Lab research site. Tokens first; dark mode redefines them. */
:root {
  --bg: #fbfaf7;
  --surface: #ffffff;
  --sunken: #f3f1ec;
  --ink: #1b1d21;
  --ink-2: #4a4f57;
  --ink-3: #7a8089;
  --line: #e4e1da;
  --line-2: #d3cfc6;
  --accent: #b86a00;
  --accent-soft: #fbefdc;
  --up: #1e7f4f;
  --down: #b4322f;
  --warn: #a8660b;
  --promising-bg: #e3f3ea;
  --needs-bg: #fbf0dd;
  --reject-bg: #f8e3e2;
  --base-bg: #e8edf5;
  --base-ink: #34507a;
  --s1: #d27a00;
  --s2: #3d5f91;
  --s3: #2b8a7e;
  --s4: #8a5cb8;
  --s5: #8d939b;
  --band-train: rgba(27, 29, 33, 0.025);
  --band-val: rgba(184, 106, 0, 0.07);
  --shadow: 0 1px 2px rgba(20, 20, 20, 0.04), 0 4px 16px rgba(20, 20, 20, 0.04);
  --serif: "Source Serif 4", "Iowan Old Style", Georgia, serif;
  --sans: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --mono: "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, monospace;
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #0d0f12; --surface: #14171c; --sunken: #101317; --ink: #ebe7df; --ink-2: #b9b4aa; --ink-3: #868b93;
    --line: #242830; --line-2: #323844; --accent: #ffa83a; --accent-soft: #2a1f10; --up: #4fcf8b; --down: #ff6b65; --warn: #f0b44c;
    --promising-bg: #12291d; --needs-bg: #2b2112; --reject-bg: #2e1615; --base-bg: #172133; --base-ink: #9db8e3;
    --s1: #ffa83a; --s2: #7ea3dc; --s3: #4cc3b2; --s4: #b896e6; --s5: #7d838c;
    --band-train: rgba(255, 255, 255, 0.02); --band-val: rgba(255, 168, 58, 0.07);
    --shadow: 0 1px 2px rgba(0, 0, 0, 0.3); color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --bg: #0d0f12; --surface: #14171c; --sunken: #101317; --ink: #ebe7df; --ink-2: #b9b4aa; --ink-3: #868b93;
  --line: #242830; --line-2: #323844; --accent: #ffa83a; --accent-soft: #2a1f10; --up: #4fcf8b; --down: #ff6b65; --warn: #f0b44c;
  --promising-bg: #12291d; --needs-bg: #2b2112; --reject-bg: #2e1615; --base-bg: #172133; --base-ink: #9db8e3;
  --s1: #ffa83a; --s2: #7ea3dc; --s3: #4cc3b2; --s4: #b896e6; --s5: #7d838c;
  --band-train: rgba(255, 255, 255, 0.02); --band-val: rgba(255, 168, 58, 0.07);
  --shadow: 0 1px 2px rgba(0, 0, 0, 0.3); color-scheme: dark;
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body { margin: 0; background: var(--bg); color: var(--ink); font: 15px/1.6 var(--sans); }
a { color: inherit; text-decoration-color: var(--line-2); text-underline-offset: 3px; }
a:hover { color: var(--accent); text-decoration-color: currentColor; }
.num, td, .stat b { font-variant-numeric: tabular-nums; }
.wrap { max-width: 1120px; margin: 0 auto; padding: 0 24px; }

/* Header */
.top { position: sticky; top: 0; z-index: 10; background: color-mix(in srgb, var(--bg) 88%, transparent); backdrop-filter: blur(8px); border-bottom: 1px solid var(--line); }
.top .wrap { display: flex; align-items: center; gap: 28px; height: 58px; }
.brand { display: flex; align-items: center; gap: 10px; font-weight: 650; letter-spacing: -0.01em; text-decoration: none; white-space: nowrap; }
.brand svg { width: 22px; height: 22px; }
.brand small { color: var(--ink-3); font-weight: 500; }
.nav { display: flex; gap: 4px; overflow-x: auto; scrollbar-width: none; }
.nav a { padding: 6px 10px; border-radius: 6px; text-decoration: none; color: var(--ink-2); font-size: 14px; white-space: nowrap; }
.nav a:hover { background: var(--sunken); color: var(--ink); }
.nav a.on { color: var(--ink); background: var(--sunken); font-weight: 550; }
.theme { margin-left: auto; border: 1px solid var(--line); background: var(--surface); color: var(--ink-2); border-radius: 6px; width: 32px; height: 32px; cursor: pointer; flex: none; }

/* Type */
h1, h2, h3 { letter-spacing: -0.015em; line-height: 1.2; }
h1 { font: 600 40px/1.12 var(--serif); margin: 0 0 14px; letter-spacing: -0.02em; max-width: 30ch; text-wrap: balance; }
h1.long { font-size: 30px; max-width: 40ch; }
h2 { font: 600 24px/1.25 var(--serif); margin: 0 0 6px; }
h3 { font-size: 15px; margin: 0 0 8px; }
.eyebrow { font: 600 12px/1 var(--sans); letter-spacing: 0.08em; text-transform: uppercase; color: var(--accent); margin-bottom: 14px; }
.lede { font-size: 18px; color: var(--ink-2); max-width: 70ch; margin: 0; }
.muted { color: var(--ink-3); }
.small { font-size: 13px; }
.prose { max-width: 72ch; }
.prose p { margin: 0 0 12px; }
.prose b { color: var(--ink); font-weight: 600; }
.crumbs { font-size: 13px; color: var(--ink-3); margin: 28px 0 18px; }
.crumbs a { color: var(--ink-3); }

/* Sections */
.hero { padding: 64px 0 40px; }
.page-head { padding: 0 0 28px; border-bottom: 1px solid var(--line); margin-bottom: 8px; }
section { padding: 36px 0; border-top: 1px solid var(--line); }
section:first-of-type { border-top: 0; }
.sec-head { display: flex; align-items: baseline; justify-content: space-between; gap: 16px; margin-bottom: 18px; flex-wrap: wrap; }
.sec-head p { margin: 0; color: var(--ink-3); max-width: 64ch; }

/* Cards and grids */
.grid { display: grid; gap: 16px; }
.g2 { grid-template-columns: repeat(auto-fit, minmax(320px, 1fr)); }
.g3 { grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); }
.card { background: var(--surface); border: 1px solid var(--line); border-radius: 10px; padding: 20px; box-shadow: var(--shadow); min-width: 0; }
a.card { display: block; text-decoration: none; transition: border-color 0.15s, transform 0.15s; }
a.card:hover { border-color: var(--line-2); color: inherit; transform: translateY(-1px); }
a.card:hover h3 { color: var(--accent); }
.card h3 { font-size: 16px; line-height: 1.35; }
.card p { margin: 6px 0 0; color: var(--ink-2); font-size: 14px; }
.card .meta { display: flex; gap: 14px; margin-top: 14px; font-size: 13px; color: var(--ink-3); flex-wrap: wrap; align-items: center; }
.card .meta b { color: var(--ink); font-weight: 600; }
.feature { padding: 28px; border-color: var(--line-2); }
.feature-grid { display: grid; grid-template-columns: minmax(0, 1.25fr) minmax(0, 1fr); gap: 32px; }
@media (max-width: 860px) { .feature-grid { grid-template-columns: 1fr; } h1 { font-size: 32px; } }

/* Stats */
.stats { display: grid; grid-template-columns: repeat(auto-fit, minmax(150px, 1fr)); gap: 1px; background: var(--line); border: 1px solid var(--line); border-radius: 10px; overflow: hidden; margin-top: 32px; }
.stat { background: var(--surface); padding: 16px 18px; }
.stat b { display: block; font: 600 26px/1.15 var(--sans); letter-spacing: -0.02em; }
.stat span { font-size: 13px; color: var(--ink-3); }
.kpis { display: grid; grid-template-columns: repeat(auto-fit, minmax(130px, 1fr)); gap: 12px; margin: 18px 0; }
.kpi { border: 1px solid var(--line); border-radius: 8px; padding: 12px 14px; background: var(--surface); }
.kpi b { display: block; font-size: 22px; font-weight: 600; letter-spacing: -0.02em; font-variant-numeric: tabular-nums; }
.kpi span { font-size: 12px; color: var(--ink-3); }
.kpi small { display: block; font-size: 12px; color: var(--ink-3); margin-top: 2px; }

/* Verdict pills */
.pill { display: inline-flex; align-items: center; gap: 6px; font: 600 11px/1 var(--sans); letter-spacing: 0.05em; text-transform: uppercase; padding: 5px 8px; border-radius: 999px; white-space: nowrap; }
.pill::before { content: ""; width: 6px; height: 6px; border-radius: 50%; background: currentColor; }
.pill.promising { background: var(--promising-bg); color: var(--up); }
.pill.needs_work { background: var(--needs-bg); color: var(--warn); }
.pill.reject { background: var(--reject-bg); color: var(--down); }
.pill.baseline { background: var(--base-bg); color: var(--base-ink); }
.pill.go { background: var(--promising-bg); color: var(--up); }
.pill.revise { background: var(--needs-bg); color: var(--warn); }
.pill.drop { background: var(--reject-bg); color: var(--down); }
.callout { border-left: 3px solid var(--accent); background: var(--accent-soft); padding: 14px 18px; border-radius: 0 8px 8px 0; margin: 16px 0; }
.callout.reject { border-color: var(--down); background: var(--reject-bg); }
.callout.promising { border-color: var(--up); background: var(--promising-bg); }
.callout.baseline { border-color: var(--base-ink); background: var(--base-bg); }
.callout p { margin: 0; }

/* Tables */
.table-wrap { overflow-x: auto; border: 1px solid var(--line); border-radius: 10px; background: var(--surface); }
table { border-collapse: collapse; width: 100%; font-size: 14px; }
th, td { padding: 9px 12px; text-align: right; border-bottom: 1px solid var(--line); white-space: nowrap; }
th { font-size: 12px; font-weight: 600; color: var(--ink-3); background: var(--sunken); position: sticky; top: 0; }
tr:last-child td { border-bottom: 0; }
.l { text-align: left; }
td.l { white-space: normal; }
tbody tr:hover td { background: var(--sunken); }
th[data-sort] { cursor: pointer; user-select: none; }
th[data-sort]::after { content: " ↕"; opacity: 0.35; }
th.asc::after { content: " ↑"; opacity: 1; } th.desc::after { content: " ↓"; opacity: 1; }
.up { color: var(--up); } .down { color: var(--down); }
tr.star td { background: var(--accent-soft); font-weight: 600; }
.filters { display: flex; gap: 6px; flex-wrap: wrap; margin-bottom: 12px; }
.filters button { border: 1px solid var(--line); background: var(--surface); color: var(--ink-2); padding: 6px 12px; border-radius: 999px; font: 500 13px var(--sans); cursor: pointer; }
.filters button.on { border-color: var(--ink); color: var(--ink); }

/* Charts */
.chart { margin: 0; background: var(--surface); border: 1px solid var(--line); border-radius: 10px; padding: 14px 14px 6px; }
.chart figcaption { display: flex; justify-content: space-between; gap: 12px; flex-wrap: wrap; font-size: 13px; font-weight: 600; margin-bottom: 6px; }
.legend { display: inline-flex; gap: 14px; flex-wrap: wrap; font-weight: 400; color: var(--ink-2); font-size: 12px; }
.legend i { display: inline-block; width: 10px; height: 3px; border-radius: 2px; margin-right: 6px; vertical-align: middle; }
.chart svg { width: 100%; height: auto; display: block; overflow: visible; }
.chart .grid { stroke: var(--line); stroke-width: 1; }
.chart .grid.zero { stroke: var(--line-2); }
.chart .tick { fill: var(--ink-3); font: 11px var(--sans); }
.chart .line { fill: none; stroke-width: 1.5; stroke-linejoin: round; opacity: 0.85; }
.chart .line.lead { stroke-width: 2.2; opacity: 1; }
.chart .line.thin { stroke-width: 1.2; }
.chart .end-label { font: 600 11px var(--sans); }
.chart .annot { fill: var(--ink-2); font: 11px var(--sans); }
.chart .dd-fill { opacity: 0.16; }
.band-train { fill: var(--band-train); } .band-val { fill: var(--band-val); }
.band-label { fill: var(--ink-3); font: 600 10px var(--sans); letter-spacing: 0.06em; text-transform: uppercase; }
.spark { width: 120px; height: 32px; } .spark polyline { fill: none; stroke: var(--s1); stroke-width: 1.5; }
.stack { display: flex; height: 14px; border-radius: 4px; overflow: hidden; gap: 2px; margin: 10px 0 8px; }
.stack-key { gap: 18px; }
.weights { display: grid; gap: 6px; }
.wrow { display: grid; grid-template-columns: 48px minmax(0, 1fr) minmax(80px, 1.2fr) 56px; gap: 10px; align-items: center; font-size: 13px; }
.wsym { font-weight: 600; } .wname { color: var(--ink-3); overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.wbar { background: var(--sunken); height: 8px; border-radius: 4px; overflow: hidden; } .wbar b { display: block; height: 100%; background: var(--s1); }
.wrow .num { text-align: right; }
.grid-table { width: auto; margin-top: 4px; }
.grid-table caption { text-align: left; font-size: 13px; color: var(--ink-3); padding-bottom: 8px; }
.grid-table th { background: transparent; position: static; }
td.heat { background: color-mix(in srgb, var(--s1) calc(var(--a) * 100%), transparent); text-align: center; min-width: 64px; }

/* Pipeline */
.pipeline { display: grid; grid-template-columns: repeat(5, minmax(0, 1fr)); gap: 12px; counter-reset: step; }
@media (max-width: 860px) { .pipeline { grid-template-columns: 1fr 1fr; } }
@media (max-width: 520px) { .pipeline { grid-template-columns: 1fr; } }
.step { border: 1px solid var(--line); border-radius: 10px; padding: 16px; background: var(--surface); position: relative; }
.step::before { counter-increment: step; content: counter(step, decimal-leading-zero); font: 600 12px var(--mono); color: var(--accent); display: block; margin-bottom: 8px; }
.step h3 { margin-bottom: 4px; } .step p { margin: 0; font-size: 13px; color: var(--ink-2); }

/* Detail layout */
.two { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); gap: 24px; }
@media (max-width: 860px) { .two { grid-template-columns: 1fr; } }
dl.facts { display: grid; grid-template-columns: max-content 1fr; gap: 6px 18px; margin: 0; font-size: 14px; }
dl.facts dt { color: var(--ink-3); } dl.facts dd { margin: 0; }
details.code { border: 1px solid var(--line); border-radius: 10px; background: var(--surface); }
details.code summary { cursor: pointer; padding: 12px 16px; font-weight: 600; font-size: 14px; }
details.code pre { margin: 0; padding: 16px; border-top: 1px solid var(--line); overflow-x: auto; font: 12.5px/1.55 var(--mono); background: var(--sunken); border-radius: 0 0 10px 10px; }
.toc { display: flex; gap: 6px; flex-wrap: wrap; margin: 18px 0 0; }
.toc a { font-size: 13px; padding: 5px 10px; border: 1px solid var(--line); border-radius: 999px; text-decoration: none; color: var(--ink-2); background: var(--surface); }
.toc a:hover { border-color: var(--accent); }
.md h2 { margin-top: 28px; } .md h3 { margin-top: 20px; } .md ul, .md ol { padding-left: 22px; } .md li { margin: 4px 0; }
.md code, .prose code { font: 0.9em var(--mono); background: var(--sunken); padding: 1px 5px; border-radius: 4px; }
.md table { margin: 12px 0; border: 1px solid var(--line); }
.md td, .md th { white-space: normal; text-align: left; }

footer { border-top: 1px solid var(--line); margin-top: 48px; padding: 28px 0 48px; color: var(--ink-3); font-size: 13px; }
footer .wrap { display: flex; justify-content: space-between; gap: 16px; flex-wrap: wrap; }

@media (max-width: 600px) {
  .wrap { padding: 0 16px; }
  .hero { padding: 40px 0 28px; }
  .top .wrap { gap: 14px; }
  .brand small { display: none; }
  .lede { font-size: 16px; }
}
@media (max-width: 700px) {
  .top .wrap { flex-wrap: wrap; height: auto; padding-top: 10px; padding-bottom: 6px; row-gap: 6px; }
  .nav { order: 3; width: 100%; margin: 0 -10px; }
  .theme { margin-left: auto; }
}