/* ==========================================================================
   BVSR project page
   Blue  = Blind Variation · Orange = Selective Retention · Green = BVSR
   ========================================================================== */

:root {
  color-scheme: light;
  --bg: #fbfaf7;
  --surface: #ffffff;
  --surface-2: #f4f2ec;
  --ink: #1c2026;
  --ink-2: #4a525d;
  --ink-3: #7a828d;
  --rule: #e3dfd6;
  --rule-2: #eeebe4;

  --bv: #2f66b3;
  --bv-deep: #1c4c8c;
  --bv-soft: #8fb0dc;
  --bv-tint: #e7eef9;

  --sr: #d07a1f;
  --sr-deep: #984c08;
  --sr-soft: #e6b27a;
  --sr-tint: #fbeedc;

  --bvsr: #2c9a78;
  --bvsr-deep: #1d6e55;
  --bvsr-tint: #e0f1ea;

  --gold: #a9781f;
  --base: #9299a3;        /* neutral reference series */
  --base-soft: #c9cdd3;
  --grid: #e9e6df;
  --shadow: 0 1px 2px rgba(28, 32, 38, .04), 0 8px 28px rgba(28, 32, 38, .06);

  --serif: "Source Serif 4", "Source Serif Pro", Charter, "Iowan Old Style", Georgia, serif;
  --sans: "Inter", ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  --mono: "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;

  --measure: 880px;      /* one column width for prose, figures, tables and video */
  --wide: 880px;
  --radius: 14px;
}

:root[data-theme="dark"] {
  color-scheme: dark;
  --bg: #14161a;
  --surface: #1b1e24;
  --surface-2: #22262d;
  --ink: #ece9e3;
  --ink-2: #b9bfc8;
  --ink-3: #8a919b;
  --rule: #2f343c;
  --rule-2: #272b32;

  --bv: #5088dc;
  --bv-deep: #94b8f0;
  --bv-soft: #46669b;
  --bv-tint: #1a2a45;

  --sr: #cc8030;
  --sr-deep: #ecb276;
  --sr-soft: #8a5f33;
  --sr-tint: #382915;

  --bvsr: #2fa37f;
  --bvsr-deep: #7ad3b3;
  --bvsr-tint: #14322a;

  --gold: #d9ac55;
  --base: #8a919b;
  --base-soft: #4a5059;
  --grid: #2a2e35;
  --shadow: 0 1px 2px rgba(0, 0, 0, .3), 0 8px 28px rgba(0, 0, 0, .28);
}

*, *::before, *::after { box-sizing: border-box; }

html { scroll-behavior: smooth; scroll-padding-top: 76px; -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--serif);
  font-size: 19px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

a { color: var(--bv-deep); text-decoration-color: color-mix(in srgb, var(--bv-deep) 35%, transparent); text-underline-offset: 3px; }
a:hover { text-decoration-color: currentColor; }

::selection { background: color-mix(in srgb, var(--bv) 22%, transparent); }

.bv { color: var(--bv-deep); font-weight: 600; }
.sr { color: var(--sr-deep); font-weight: 600; }
.bvsr { color: var(--bvsr-deep); font-weight: 600; }
.gold { color: var(--gold); }

/* ------------------------------------------------------------------ top bar */
.topbar {
  position: sticky; top: 0; z-index: 50;
  display: flex; align-items: center; gap: 20px;
  height: 56px; padding: 0 24px;
  background: color-mix(in srgb, var(--bg) 86%, transparent);
  backdrop-filter: saturate(1.4) blur(12px);
  -webkit-backdrop-filter: saturate(1.4) blur(12px);
  border-bottom: 1px solid var(--rule);
  font-family: var(--sans); font-size: 14px;
}
.brand { display: flex; align-items: baseline; gap: 11px; color: var(--ink); text-decoration: none; }
.brand-logo { display: block; height: 18px; width: auto; }   /* its bottom edge is the wordmark's baseline */
:root[data-theme="dark"] .brand-logo { filter: brightness(0) invert(1); opacity: .92; }   /* white wordmark on the dark bar */
.brand-sep { width: 1px; height: 20px; background: var(--ink-3); opacity: .45; align-self: center; }
.brand-name { font-size: 22px; font-weight: 700; line-height: 1; letter-spacing: .01em; }   /* cap height matches the wordmark's */
.topnav { display: flex; gap: 4px; margin-left: auto; }
.topnav a {
  color: var(--ink-2); text-decoration: none; padding: 6px 10px; border-radius: 8px; white-space: nowrap;
  transition: color .15s, background .15s;
}
.topnav a:hover { color: var(--ink); background: var(--surface-2); }
.topnav a.active { color: var(--ink); background: var(--surface-2); }
.icon-btn {
  display: inline-grid; place-items: center; width: 34px; height: 34px; flex: none;
  border: 1px solid var(--rule); border-radius: 9px; background: var(--surface); color: var(--ink-2); cursor: pointer;
}
.icon-btn:hover { color: var(--ink); border-color: var(--ink-3); }
.icon-btn svg { width: 17px; height: 17px; }
.icon-btn .moon { display: none; }
:root[data-theme="dark"] .icon-btn .sun { display: none; }
:root[data-theme="dark"] .icon-btn .moon { display: block; }
.progress { position: absolute; left: 0; bottom: -1px; height: 2px; width: 100%; transform-origin: 0 50%; transform: scaleX(0);
  background: linear-gradient(90deg, var(--bv), var(--sr)); }

/* ------------------------------------------------------------------ layout */
main { display: block; }
.col { width: min(var(--measure), calc(100% - 40px)); margin-inline: auto; }
.wide { width: min(var(--wide), calc(100% - 40px)); margin-inline: auto; }

section { padding-block: 34px; }
h1, h2, h3 { font-family: var(--serif); color: var(--ink); line-height: 1.18; letter-spacing: -.012em; }
h2 { font-size: clamp(27px, 3.4vw, 35px); font-weight: 600; margin: 0 0 18px; }
h3 { font-size: 22px; font-weight: 600; margin: 40px 0 10px; }
p { margin: 0 0 1.05em; }
.kicker {
  display: flex; align-items: center; gap: 10px; margin-bottom: 10px;
  font-family: var(--sans); font-size: 12.5px; font-weight: 600; letter-spacing: .12em; text-transform: uppercase; color: var(--ink-3);
}
.kicker::before { content: ""; width: 22px; height: 2px; background: currentColor; border-radius: 2px; }
.kicker.k-bv { color: var(--bv-deep); }
.kicker.k-sr { color: var(--sr-deep); }
.kicker.k-bvsr { color: var(--bvsr-deep); }
.lede { font-size: 21px; line-height: 1.6; color: var(--ink-2); }
strong { font-weight: 600; }
sup.fn { font-family: var(--sans); font-size: .62em; }
hr.sep { border: 0; height: 1px; background: var(--rule); width: min(var(--measure), calc(100% - 40px)); margin: 26px auto; }

/* ------------------------------------------------------------------ hero */
.hero { padding: 76px 0 30px; text-align: center; position: relative; overflow: hidden; }
.hero-dots { position: absolute; inset: 0; width: 100%; height: 100%; pointer-events: none; opacity: .55; }
.hero > .wide { position: relative; }
.badge {
  display: inline-flex; align-items: center; gap: 8px; padding: 5px 13px; border-radius: 999px;
  border: 1px solid var(--rule); background: var(--surface);
  font-family: var(--sans); font-size: 12.5px; font-weight: 500; color: var(--ink-2); letter-spacing: .02em;
}
.badge i { width: 7px; height: 7px; border-radius: 50%; background: var(--bvsr); }
.hero h1 { font-size: clamp(30px, 4.5vw, 52px); font-weight: 600; margin: 0 0 14px; letter-spacing: -.022em; line-height: 1.1; white-space: nowrap; }
.hero h1 .bv, .hero h1 .sr { font-weight: 600; }
.hero .subtitle { font-size: clamp(19px, 2.4vw, 25px); color: var(--ink-2); margin: 0 auto 30px; max-width: 30em; line-height: 1.4; font-style: italic; }
.authors { font-family: var(--sans); font-size: 16.5px; display: flex; flex-wrap: wrap; justify-content: center; align-items: baseline; gap: 4px 22px; margin: 0 auto 8px; max-width: 760px; }
.authors span { white-space: nowrap; color: var(--ink); font-weight: 500; }
.authors a { color: inherit; text-decoration: none; border-radius: 3px; transition: color .15s; }
.authors a:hover, .authors a:focus-visible { color: var(--bv-deep); text-decoration: underline; text-decoration-thickness: 1.5px; text-underline-offset: 4px; }
.authors sup { color: var(--ink-3); font-weight: 400; margin-left: 1px; line-height: 0; }
.affil { font-family: var(--sans); font-size: 14.5px; font-weight: 500; color: var(--ink-2); margin-bottom: 28px; display: flex; flex-wrap: wrap; justify-content: center; gap: 2px 26px; }
.affil sup { line-height: 0; margin-right: 2px; }
.cta { display: flex; flex-wrap: wrap; justify-content: center; gap: 10px; }
.btn {
  display: inline-flex; align-items: center; gap: 8px; height: 42px; padding: 0 18px; border-radius: 999px;
  font-family: var(--sans); font-size: 14.5px; font-weight: 600; text-decoration: none; cursor: pointer;
  border: 1px solid var(--rule); background: var(--surface); color: var(--ink);
  transition: transform .15s, border-color .15s, background .15s;
}
.btn:hover { transform: translateY(-1px); border-color: var(--ink-3); }
.btn.primary { background: var(--ink); color: var(--bg); border-color: var(--ink); }
.btn svg { width: 16px; height: 16px; }
.btn .hf-logo { width: 20px; height: 20px; display: block; margin: 0 -1px; }
.btn[aria-disabled="true"] { opacity: .55; cursor: default; pointer-events: none; }
.btn small { font-weight: 500; opacity: .7; }

/* ------------------------------------------------------------------ figures */
figure { margin: 30px auto; }
.fig {
  background: var(--surface); border: 1px solid var(--rule); border-radius: var(--radius);
  box-shadow: var(--shadow); padding: 22px 24px 20px; font-family: var(--sans);
}
.fig-head { display: flex; flex-wrap: wrap; align-items: flex-start; justify-content: space-between; gap: 10px 20px; margin-bottom: 14px; }
.fig-title { font-size: 15.5px; font-weight: 650; color: var(--ink); line-height: 1.35; }
.fig-sub { font-size: 13px; color: var(--ink-3); margin-top: 2px; line-height: 1.45; }
.fig-tag {
  display: inline-flex; align-items: center; gap: 6px; font-size: 11px; font-weight: 700; letter-spacing: .1em; text-transform: uppercase;
  color: var(--ink-3); border: 1px solid var(--rule); padding: 3px 9px; border-radius: 999px; white-space: nowrap;
}
.fig-tag.live::before { content: ""; width: 6px; height: 6px; border-radius: 50%; background: var(--bvsr); box-shadow: 0 0 0 3px color-mix(in srgb, var(--bvsr) 22%, transparent); }
figcaption { width: min(var(--measure), 100%); margin: 12px auto 0; font-family: var(--sans); font-size: 13.5px; line-height: 1.55; color: var(--ink-3); }
figcaption b { color: var(--ink-2); font-weight: 600; }

svg text { font-family: var(--sans); }
.ax text { font-size: 11px; fill: var(--ink-3); font-variant-numeric: tabular-nums; }
.ax line, .ax path { stroke: var(--ink-3); stroke-width: 1; fill: none; }
.gridline { stroke: var(--grid); stroke-width: 1; }
.ax-label { font-size: 11.5px; fill: var(--ink-2); }

.legend { display: flex; flex-wrap: wrap; gap: 6px 16px; font-size: 13px; color: var(--ink-2); align-items: center; }
.legend .key { display: inline-flex; align-items: center; gap: 7px; }
.legend .swatch { width: 18px; height: 3px; border-radius: 2px; background: currentColor; flex: none; }
.legend .swatch.dot { width: 8px; height: 8px; border-radius: 50%; }
.legend .swatch.dotted { background: none; border-top: 2px dotted currentColor; height: 0; }
.legend button.key { font: inherit; color: inherit; border: 1px solid var(--rule); background: var(--surface); padding: 4px 10px; border-radius: 999px; cursor: pointer; }
.legend button.key[aria-pressed="false"] { opacity: .45; }
.legend button.key:hover { border-color: var(--ink-3); }

/* segmented control + sliders */
.seg { display: inline-flex; padding: 3px; background: var(--surface-2); border-radius: 10px; gap: 2px; }
.seg button {
  font: 600 13px var(--sans); color: var(--ink-2); border: 0; background: none; padding: 6px 13px; border-radius: 8px; cursor: pointer; white-space: nowrap;
}
.seg button[aria-pressed="true"] { background: var(--surface); color: var(--ink); box-shadow: 0 1px 2px rgba(0, 0, 0, .1); }
.seg button:focus-visible, .btn:focus-visible, .icon-btn:focus-visible, .chip:focus-visible, .legend button:focus-visible { outline: 2px solid var(--bv); outline-offset: 2px; }

input[type="range"] { -webkit-appearance: none; appearance: none; width: 100%; height: 22px; background: none; margin: 0; cursor: pointer; --fill: 50%; --c: var(--bv); }
input[type="range"]::-webkit-slider-runnable-track { height: 6px; border-radius: 6px; background: linear-gradient(90deg, var(--c) var(--fill), var(--rule) var(--fill)); }
input[type="range"]::-moz-range-track { height: 6px; border-radius: 6px; background: linear-gradient(90deg, var(--c) var(--fill), var(--rule) var(--fill)); }
input[type="range"]::-webkit-slider-thumb { -webkit-appearance: none; width: 20px; height: 20px; margin-top: -7px; border-radius: 50%; background: var(--surface); border: 2.5px solid var(--c); box-shadow: 0 1px 4px rgba(0, 0, 0, .18); }
input[type="range"]::-moz-range-thumb { width: 16px; height: 16px; border-radius: 50%; background: var(--surface); border: 2.5px solid var(--c); box-shadow: 0 1px 4px rgba(0, 0, 0, .18); }
input[type="range"]:focus-visible { outline: none; }
input[type="range"]:focus-visible::-webkit-slider-thumb { box-shadow: 0 0 0 4px color-mix(in srgb, var(--c) 30%, transparent); }
input[type="range"].c-sr { --c: var(--sr); }
input[type="range"].c-bvsr { --c: var(--bvsr); }
input[type="range"].c-ink { --c: var(--ink-2); }

.chip {
  font: 500 13px var(--sans); color: var(--ink-2); background: var(--surface); border: 1px solid var(--rule); border-radius: 999px;
  padding: 5px 12px; cursor: pointer; transition: border-color .15s, color .15s, background .15s;
}
.chip:hover { border-color: var(--ink-3); color: var(--ink); }
.chip[aria-pressed="true"] { background: var(--ink); color: var(--bg); border-color: var(--ink); }
.chips { display: flex; flex-wrap: wrap; gap: 8px; }

.tooltip {
  position: fixed; z-index: 80; pointer-events: none; opacity: 0; transform: translateY(4px); transition: opacity .12s, transform .12s;
  background: var(--ink); color: var(--bg); font: 500 12.5px/1.45 var(--sans); padding: 8px 11px; border-radius: 9px; max-width: 260px;
  box-shadow: 0 6px 22px rgba(0, 0, 0, .25); font-variant-numeric: tabular-nums;
}
.tooltip.on { opacity: 1; transform: none; }
.tooltip b { font-weight: 650; }
.tooltip .row { display: flex; justify-content: space-between; gap: 14px; }
.tooltip .row i { display: inline-block; width: 8px; height: 8px; border-radius: 50%; margin-right: 6px; }
.tooltip .t-h { opacity: .7; margin-bottom: 3px; }

/* ------------------------------------------------------------------ overview figure */
.pipeline { display: flex; align-items: center; justify-content: center; flex-wrap: wrap; gap: 6px 8px; margin: 2px 0 16px; }
.stage { display: inline-flex; align-items: center; gap: 8px; padding: 8px 15px; border-radius: 999px; background: var(--surface-2); font-size: 14px; font-weight: 600; color: var(--ink); border: 1.5px solid transparent; }
.stage svg { width: 16px; height: 16px; color: var(--ink-2); }
.stage.is-bv { background: var(--bv-tint); border-color: var(--bv); }
.stage.is-bv svg { color: var(--bv-deep); }
.stage.is-sr { background: var(--sr-tint); border-color: var(--sr); }
.stage.is-sr svg { color: var(--sr-deep); }
.pipe-arrow { color: var(--ink-3); width: 22px; height: 12px; flex: none; }
.ov-grid { display: grid; grid-template-columns: 1fr; gap: 14px; }
.ov-grid > *, .bv-row > *, .sr-row > *, .dial-top > *, .calc > *, .toy > *, .srfig > *, .case > * { min-width: 0; }
.ov-panel { border-radius: 12px; padding: 18px 18px 16px; border: 1px solid; }
.ov-panel.p-bv { background: color-mix(in srgb, var(--bv-tint) 55%, var(--surface)); border-color: color-mix(in srgb, var(--bv) 35%, transparent); }
.ov-panel.p-sr { background: color-mix(in srgb, var(--sr-tint) 55%, var(--surface)); border-color: color-mix(in srgb, var(--sr) 35%, transparent); }
.ov-panel h4 { margin: 0 0 2px; font: 700 18px var(--sans); letter-spacing: -.01em; }
.ov-panel .ov-sub { font-size: 13.5px; color: var(--ink-2); margin-bottom: 14px; }
.p-bv h4 { color: var(--bv-deep); }
.p-sr h4 { color: var(--sr-deep); }
.bv-row { display: grid; grid-template-columns: minmax(0, 1.25fr) auto minmax(0, 1fr); gap: 12px; align-items: stretch; }
.bv-row + .bv-row { margin-top: 10px; }
.bv-arrow { display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 2px; color: var(--ink-3); font-size: 11.5px; }
.bv-arrow svg { width: 40px; height: 12px; }
.ov-card { background: var(--surface); border: 1px solid var(--rule); border-radius: 10px; padding: 11px 13px; font-size: 13px; line-height: 1.5; color: var(--ink-2); }
.ov-card .cap { font-size: 11px; font-weight: 700; letter-spacing: .08em; text-transform: uppercase; color: var(--ink-3); margin-bottom: 5px; }
.p-bv .ov-card.on { border-color: color-mix(in srgb, var(--bv) 55%, transparent); }
.p-bv .ov-card.on .cap { color: var(--bv-deep); }
.ov-card .doc { font-family: var(--serif); font-size: 14px; color: var(--ink); line-height: 1.45; }
.ov-card .doc b { font-weight: 600; }
.ov-card .doc span { color: var(--ink-3); }
.redact { display: inline-block; height: .78em; border-radius: 2px; background: var(--ink); vertical-align: -1px; margin-right: 3px; }
.ov-down { text-align: center; color: var(--ink-3); font-size: 12px; line-height: 1; padding: 7px 0; }
.ov-out { display: flex; align-items: center; gap: 10px; min-height: 66px; }
.ov-out svg { flex: none; }
.ov-out .t b { display: block; color: var(--ink); font-weight: 650; font-size: 13.5px; }
.ov-out .t > span { font-size: 12.5px; color: var(--ink-3); }
.p-bv .ov-out.on .t b { color: var(--bv-deep); }
.field-tags { display: flex; flex-wrap: wrap; gap: 5px; }
.ftag { display: inline-block; padding: 2px 8px; border-radius: 6px; color: #fff; font-size: 11.5px; font-weight: 650; letter-spacing: .01em; }
.ftag.math { background: #3f8f84; } .ftag.phys { background: #6a58c4; } .ftag.cs { background: #5a6677; }
.ftag.bio { background: #4f9a4c; } .ftag.econ { background: #a84d7b; }
.sr-flow { display: grid; grid-template-columns: 1fr; gap: 0; }
.sr-row { display: grid; grid-template-columns: minmax(0, 1fr) auto minmax(0, 1fr); gap: 18px; align-items: center; }
.sr-selector { width: 150px; height: 84px; display: grid; place-items: center; color: #fff; font: 700 13px/1.25 var(--sans); text-align: center; background: var(--sr);
  clip-path: polygon(0 0, 100% 18%, 100% 82%, 0 100%); padding-right: 6px; }
.sr-selector small { display: block; font-weight: 500; font-size: 11.5px; opacity: .92; }
.sr-outs { display: grid; gap: 7px; }
.sr-out { border-radius: 9px; padding: 7px 10px; font-size: 12.5px; display: flex; align-items: center; justify-content: space-between; gap: 8px; background: var(--surface); }
.sr-out.keep { border: 1.5px solid var(--sr); color: var(--sr-deep); font-weight: 650; }
.sr-out.drop { border: 1.5px dashed var(--rule); color: var(--ink-3); }
.sr-out svg { flex: none; }

/* ------------------------------------------------------------------ video */
.video-shell { border-radius: var(--radius); overflow: hidden; border: 1px solid var(--rule); box-shadow: var(--shadow); background: #0e1014; aspect-ratio: 16 / 9; }
.video-shell video { display: block; width: 100%; height: 100%; }

/* ------------------------------------------------------------------ equations */
.eq { margin: 22px auto; padding: 18px 20px; text-align: center; overflow-x: auto; background: var(--surface); border: 1px solid var(--rule); border-radius: 12px; font-size: 17px; }
.eq .katex-display { margin: 0; }
.eq-note { font-family: var(--sans); font-size: 13px; color: var(--ink-3); margin-top: 8px; }
.prop {
  margin: 26px 0; padding: 16px 20px 14px; background: var(--surface-2); border-left: 3px solid var(--ink-3); border-radius: 0 10px 10px 0;
  font-size: 17px; line-height: 1.6;
}
.prop .p-h { font-family: var(--sans); font-size: 12px; font-weight: 700; letter-spacing: .1em; text-transform: uppercase; color: var(--ink-3); margin-bottom: 6px; }
.prop.p-bv { border-left-color: var(--bv); } .prop.p-bv .p-h { color: var(--bv-deep); }
.prop.p-sr { border-left-color: var(--sr); } .prop.p-sr .p-h { color: var(--sr-deep); }
.prop p:last-child { margin-bottom: 0; }

/* ------------------------------------------------------------------ creativity calculator */
.calc { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, .9fr); gap: 26px 34px; align-items: center; }
.calc-row { display: grid; grid-template-columns: 1fr auto; gap: 2px 12px; align-items: baseline; margin-bottom: 14px; }
.calc-row label { font-size: 14px; font-weight: 600; color: var(--ink); }
.calc-row label small { display: block; font-weight: 400; color: var(--ink-3); font-size: 12.5px; }
.calc-row output { font: 600 14px var(--mono); color: var(--ink-2); }
.calc-row input { grid-column: 1 / -1; }
.calc-out { display: grid; gap: 9px; }
.term { display: grid; grid-template-columns: 158px 1fr 46px; gap: 10px; align-items: center; font-size: 13px; color: var(--ink-2); }
.term .track { height: 10px; background: var(--surface-2); border-radius: 6px; overflow: hidden; }
.term .track i { display: block; height: 100%; width: 0; border-radius: 6px; background: var(--ink-3); transition: width .18s; }
.term b { font: 600 13px var(--mono); color: var(--ink); text-align: right; }
.term.result { margin-top: 6px; padding-top: 12px; border-top: 1px solid var(--rule); font-weight: 650; color: var(--ink); font-size: 14px; }
.term.result .track { height: 14px; }
.term.result .track i { background: var(--gold); }
.term.result b { font-size: 16px; color: var(--gold); }
.calc-verdict { margin-top: 10px; font-size: 13.5px; color: var(--ink-2); min-height: 2.9em; line-height: 1.45; }

.measure-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 14px; margin: 26px 0 8px; }
.mcard { background: var(--surface); border: 1px solid var(--rule); border-radius: 12px; padding: 16px 18px; font-family: var(--sans); font-size: 14px; line-height: 1.55; color: var(--ink-2); }
.mcard h4 { margin: 0 0 2px; font-size: 15.5px; color: var(--ink); }
.mcard .sym { font: 500 13px var(--mono); color: var(--ink-3); margin-bottom: 8px; }

/* ------------------------------------------------------------------ toy model */
.toy { display: grid; grid-template-columns: minmax(0, 1fr) 232px; gap: 22px 28px; align-items: start; }
.toy svg { width: 100%; height: auto; display: block; }
.toy-dot { transition: transform .45s cubic-bezier(.3, .7, .2, 1); fill: var(--bv); }
.toy-dot.star { fill: var(--gold); }
.toy-col { fill: var(--surface-2); }
.toy-col.hi { fill: color-mix(in srgb, var(--gold) 14%, var(--surface-2)); }
.readouts { display: grid; gap: 10px; }
.ro { border: 1px solid var(--rule); border-radius: 10px; padding: 10px 13px; background: var(--surface); }
.ro .l { font-size: 12px; color: var(--ink-3); line-height: 1.35; }
.ro .v { font-size: 24px; font-weight: 650; letter-spacing: -.01em; font-variant-numeric: tabular-nums; color: var(--ink); line-height: 1.25; }
.ro .v small { font-size: 13px; font-weight: 500; color: var(--ink-3); letter-spacing: 0; }
.ctl { margin-top: 16px; }
.ctl-head { display: flex; justify-content: space-between; align-items: baseline; gap: 12px; font-size: 13.5px; color: var(--ink-2); margin-bottom: 4px; }
.ctl-head b { font-weight: 650; color: var(--ink); }
.ctl-head output { font: 600 14px var(--mono); color: var(--ink); white-space: nowrap; }
.ctl-ends { display: flex; justify-content: space-between; font-size: 12px; color: var(--ink-3); margin-top: 2px; }
.ctl-row { display: flex; align-items: center; gap: 12px; }
.ctl-row input { flex: 1; }
.mini-btn { font: 600 12.5px var(--sans); border: 1px solid var(--rule); background: var(--surface); color: var(--ink-2); border-radius: 8px; padding: 6px 11px; cursor: pointer; white-space: nowrap; display: inline-flex; align-items: center; gap: 6px; }
.mini-btn:hover { border-color: var(--ink-3); color: var(--ink); }
.mini-btn svg { width: 12px; height: 12px; }

/* ------------------------------------------------------------------ info dial (Fig. 2) */
.dial-top { display: grid; grid-template-columns: minmax(0, 1.25fr) minmax(0, 1fr); gap: 18px 26px; align-items: stretch; margin-bottom: 18px; }
.ctx-card { background: var(--surface-2); border-radius: 12px; padding: 14px 16px; display: flex; flex-direction: column; }
.ctx-card .cap { display: flex; justify-content: space-between; gap: 10px; font-size: 11px; font-weight: 700; letter-spacing: .09em; text-transform: uppercase; color: var(--ink-3); margin-bottom: 8px; }
.ctx-card .cap span:last-child { color: var(--bv-deep); }
.ctx-text { font-family: var(--mono); font-size: 12.5px; line-height: 1.6; color: var(--ink); flex: 1; min-height: 8.2em; }
.ctx-text .dim { color: var(--ink-3); }
.ctx-text .ctx { background: color-mix(in srgb, var(--bv) 16%, transparent); border-radius: 3px; padding: 1px 2px; box-decoration-break: clone; -webkit-box-decoration-break: clone; }
.dial-ctl { display: flex; flex-direction: column; justify-content: center; }
.bits { font-size: 44px; font-weight: 650; letter-spacing: -.03em; line-height: 1; color: var(--bv-deep); font-variant-numeric: tabular-nums; }
.bits small { font-size: 15px; font-weight: 500; color: var(--ink-3); letter-spacing: 0; margin-left: 4px; }
.dial-ticks { position: relative; height: 18px; font-size: 11.5px; color: var(--ink-3); margin: 2px 10px 0; font-variant-numeric: tabular-nums; }
.dial-ticks span { position: absolute; transform: translateX(-50%); white-space: nowrap; }
.panels { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 14px; }
.panel { border: 1px solid var(--rule-2); border-radius: 12px; padding: 12px 12px 6px; background: var(--surface); min-width: 0; }
.panel .p-name { font-size: 13px; font-weight: 650; color: var(--ink); }
.panel .p-top { display: flex; justify-content: space-between; align-items: flex-start; gap: 12px; margin-bottom: 4px; }
.panel .p-desc { font-size: 12px; color: var(--ink-3); line-height: 1.35; }
.panel .p-val { display: flex; flex-direction: column; align-items: flex-end; gap: 3px; flex: none; }
.panel .p-val b { line-height: 1.05; font-size: 25px; font-weight: 650; letter-spacing: -.02em; font-variant-numeric: tabular-nums; color: var(--ink); }
.delta { font-size: 11.5px; font-weight: 650; white-space: nowrap; padding: 2px 7px; border-radius: 999px; background: var(--surface-2); color: var(--ink-2); font-variant-numeric: tabular-nums; }
.delta.neg { background: var(--bv-tint); color: var(--bv-deep); }
.panel svg { width: 100%; height: auto; display: block; overflow: visible; touch-action: pan-y; }
.d-dot { fill: var(--bv-soft); opacity: .16; transition: opacity .2s; }
.d-dot.on { opacity: .62; }
.d-band { fill: var(--bv-tint); }
.d-trend { fill: none; stroke: var(--bv-deep); stroke-width: 2.4; stroke-linejoin: round; stroke-linecap: round; }
.d-trend.ghost { opacity: .22; }
.d-cursor { stroke: var(--ink-3); stroke-width: 1; stroke-dasharray: 3 3; }
.d-knob { fill: var(--surface); stroke: var(--bv-deep); stroke-width: 2.4; }

/* ------------------------------------------------------------------ comparison table */
.cmp { width: 100%; border-collapse: collapse; font-family: var(--sans); font-size: 14px; }
.cmp th { text-align: left; font-size: 12px; font-weight: 650; letter-spacing: .04em; color: var(--ink-3); padding: 0 12px 10px 0; border-bottom: 1px solid var(--rule); vertical-align: bottom; }
.cmp th small { display: block; font-weight: 400; letter-spacing: 0; text-transform: none; font-size: 11.5px; }
.cmp td { padding: 11px 12px 11px 0; border-bottom: 1px solid var(--rule-2); vertical-align: middle; }
.cmp tr:last-child td { border-bottom: 0; }
.cmp td.m { font-weight: 550; color: var(--ink); white-space: nowrap; width: 1%; padding-right: 22px; }
.cmp td.m small { display: block; font-weight: 400; color: var(--ink-3); font-size: 12px; }
.cmp tr.top td.m { color: var(--bv-deep); font-weight: 700; }
.cell { display: grid; grid-template-columns: 1fr; gap: 4px; min-width: 104px; }
.cell .n { font-variant-numeric: tabular-nums; color: var(--ink-2); font-size: 13.5px; }
.cell .n b { font-weight: 650; color: var(--ink); }
.cell .n small { color: var(--ink-3); font-size: 11.5px; }
.cell .bar { position: relative; height: 8px; background: var(--surface-2); border-radius: 0 4px 4px 0; }
.cell .bar i { position: absolute; left: 0; top: 0; bottom: 0; background: var(--base-soft); border-radius: 0 4px 4px 0; }
.cell .bar u { position: absolute; top: 50%; height: 2px; margin-top: -1px; background: var(--ink-2); border-radius: 1px; text-decoration: none; }
.cmp tr.top .cell .bar i { background: var(--bv); }
.cmp tr.ctl .cell .bar i { background: var(--bv-soft); }
.cmp tr.top .cell .n b { color: var(--bv-deep); }

/* ------------------------------------------------------------------ tasks */
.tasks { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 12px; }
.dom { border: 1px solid var(--rule); border-radius: 12px; padding: 13px 14px 8px; background: var(--surface); font-family: var(--sans); }
.dom h4 { margin: 0 0 8px; font-size: 12px; font-weight: 700; letter-spacing: .1em; text-transform: uppercase; color: var(--ink-3); display: flex; justify-content: space-between; gap: 8px; white-space: nowrap; }
.dom h4 span { font-weight: 500; letter-spacing: 0; text-transform: none; }
.task { padding: 8px 0; border-top: 1px solid var(--rule-2); font-size: 13.5px; line-height: 1.4; }
.task b { display: block; font-weight: 600; color: var(--ink); }
.task span { color: var(--ink-3); font-size: 12.5px; }
.models { display: flex; flex-wrap: wrap; gap: 8px; margin: 14px 0 0; font-family: var(--sans); font-size: 13px; align-items: center; color: var(--ink-3); }
.models span.m { border: 1px solid var(--rule); background: var(--surface); padding: 4px 11px; border-radius: 999px; color: var(--ink); font-weight: 500; }

/* ------------------------------------------------------------------ SR figure */
.srfig { display: grid; grid-template-columns: minmax(0, 1fr) 236px; gap: 18px 26px; align-items: start; }
.srfig svg { width: 100%; height: auto; display: block; overflow: visible; touch-action: pan-y; cursor: ew-resize; }
.s-line { fill: none; stroke-linejoin: round; stroke-linecap: round; }
.s-zs { stroke: var(--base-soft); stroke-width: 1.3; }
.s-icl { stroke: var(--base); stroke-width: 1.6; }
.s-sft { stroke: var(--sr-soft); stroke-width: 2; }
.s-sr { stroke: var(--sr-deep); stroke-width: 3; }
.s-rand { stroke: var(--ink-3); stroke-width: 1.4; stroke-dasharray: 2 4; }
.s-band { fill: color-mix(in srgb, var(--sr) 16%, transparent); }
.s-drop { fill: color-mix(in srgb, var(--ink-3) 9%, transparent); }
.s-cursor { stroke: var(--ink-2); stroke-width: 1.2; }
.s-knob { fill: var(--surface); stroke: var(--sr-deep); stroke-width: 3; }
.s-dotm { stroke: var(--surface); stroke-width: 1.5; }
.sr-list { display: grid; gap: 0; font-size: 13.5px; }
.sr-list .row { display: grid; grid-template-columns: 14px 1fr auto; gap: 8px; align-items: center; padding: 7px 0; border-bottom: 1px solid var(--rule-2); color: var(--ink-2); }
.sr-list .row:last-child { border-bottom: 0; }
.sr-list .row i { width: 10px; height: 10px; border-radius: 50%; }
.sr-list .row b { font-variant-numeric: tabular-nums; font-weight: 650; color: var(--ink); }
.sr-list .row.lead { color: var(--ink); font-weight: 650; }
.sr-list .row.lead b { color: var(--sr-deep); font-size: 17px; }
.sr-say { margin-top: 12px; padding: 12px 14px; border-radius: 10px; background: var(--sr-tint); color: var(--ink); font-size: 13.5px; line-height: 1.5; }
.sr-say b { color: var(--sr-deep); font-variant-numeric: tabular-nums; }

/* ------------------------------------------------------------------ TES + ablation */
.tes { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 12px; }
.tkey { border: 1px dashed var(--rule); border-radius: 12px; padding: 14px 16px; display: flex; flex-direction: column; justify-content: center; gap: 10px; font-size: 13px; color: var(--ink-2); line-height: 1.5; }
.tkey .legend { flex-direction: column; align-items: flex-start; gap: 7px; }
.tkey p { margin: 0; font-family: var(--sans); font-size: 12.5px; color: var(--ink-3); }
.tpanel { border: 1px solid var(--rule-2); border-radius: 12px; padding: 12px 10px 6px 12px; min-width: 0; background: var(--surface); }
.tpanel .t-top { display: flex; justify-content: space-between; align-items: flex-start; gap: 10px; }
.tpanel .t-name { font-size: 13.5px; font-weight: 650; color: var(--ink); line-height: 1.3; }
.tpanel .t-task { display: block; font-size: 11.5px; font-weight: 400; color: var(--ink-3); }
.tpanel .t-x { font-size: 24px; font-weight: 700; letter-spacing: -.02em; color: var(--bvsr-deep); line-height: 1.05; text-align: right; flex: none; }
.tpanel .t-x small { display: block; font-size: 11.5px; font-weight: 500; color: var(--ink-3); letter-spacing: 0; }
.tpanel .t-read { font-size: 12px; color: var(--ink-3); font-variant-numeric: tabular-nums; margin: 2px 0 6px; line-height: 1.5; }
.tpanel .t-read b { color: var(--ink); font-weight: 650; }
.tpanel .t-read i { display: inline-block; width: 7px; height: 7px; border-radius: 50%; margin-right: 5px; }
.tpanel svg, .apanel svg { width: 100%; height: auto; display: block; overflow: visible; touch-action: pan-y; }
.l-base { fill: none; stroke: var(--base); stroke-width: 1.8; stroke-linejoin: round; stroke-linecap: round; }
.l-bvsr { fill: none; stroke: var(--bvsr); stroke-width: 2.8; stroke-linejoin: round; stroke-linecap: round; }
.l-bv { fill: none; stroke: var(--bv); stroke-width: 2.2; stroke-linejoin: round; stroke-linecap: round; }
.l-sr { fill: none; stroke: var(--sr); stroke-width: 2.2; stroke-linejoin: round; stroke-linecap: round; }
.l-ref { stroke: var(--base); stroke-width: 1.2; stroke-dasharray: 2 3; }
.l-cursor { stroke: var(--ink-3); stroke-width: 1; }
.l-pt { stroke: var(--surface); stroke-width: 1.5; }
.abl { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; }
.apanel { border: 1px solid var(--rule-2); border-radius: 12px; padding: 12px 14px 6px; background: var(--surface); min-width: 0; }
.apanel .t-name { font-size: 14px; font-weight: 650; }
.end-label { font-size: 11px; font-weight: 650; }
.end-name { font-size: 11px; font-weight: 600; fill: var(--ink-2); }

/* ------------------------------------------------------------------ case studies */
.cases-tabs { display: flex; gap: 8px; flex-wrap: wrap; margin-bottom: 16px; }
.case { display: none; grid-template-columns: minmax(0, 1.05fr) minmax(0, 1fr); gap: 22px 30px; align-items: start; }
.case.on { display: grid; }
.transfer { display: grid; grid-template-columns: 1fr auto 1fr; gap: 10px; align-items: center; }
.tbox { border: 1px solid var(--rule); border-radius: 12px; padding: 10px 10px 8px; background: var(--surface); text-align: left; }
.tbox svg { width: 100%; height: auto; display: block; margin: 8px 0 6px; border-radius: 8px; background: var(--surface-2); }
.tbox .n { font-size: 13px; font-weight: 600; color: var(--ink); line-height: 1.3; }
.tbox .s { font-size: 11.5px; color: var(--ink-3); }
.t-arrow { color: var(--ink-3); width: 30px; }
.scores { margin-top: 16px; display: grid; gap: 8px; }
.score { display: grid; grid-template-columns: 178px 1fr 50px; gap: 12px; align-items: center; font-size: 13px; color: var(--ink-2); }
.score .track { height: 14px; position: relative; background: linear-gradient(var(--rule), var(--rule)) center / 100% 2px no-repeat; margin: 0 7px; }
.score .track i { position: absolute; top: 0; width: 14px; height: 14px; margin-left: -7px; border-radius: 50%; background: var(--base); border: 2.5px solid var(--surface); box-sizing: border-box; }
.score b { font-variant-numeric: tabular-nums; font-weight: 600; color: var(--ink); text-align: right; }
.score.win { color: var(--ink); font-weight: 650; }
.score.win .track i { background: var(--bvsr); width: 18px; height: 18px; margin-left: -9px; top: -2px; }
.score.win b { color: var(--bvsr-deep); font-weight: 700; }
.score.na .track { background: linear-gradient(90deg, var(--rule) 50%, transparent 50%) center / 8px 2px repeat-x; }
.case-body h4 { margin: 0 0 4px; font: 650 19px/1.3 var(--serif); color: var(--ink); }
.case-body .src { font-size: 12.5px; color: var(--ink-3); margin-bottom: 10px; }
.case-body p { font-family: var(--serif); font-size: 16.5px; line-height: 1.62; color: var(--ink-2); margin-bottom: .8em; }
.axis-note { font-size: 11.5px; color: var(--ink-3); margin-top: 6px; }

/* ------------------------------------------------------------------ domains */
.domains { display: grid; grid-template-columns: 1fr 1fr; gap: 14px 40px; --lab: 150px; }
.domains h4 { margin: 0 0 10px; font-size: 14px; font-weight: 650; }
.dbar { display: grid; grid-template-columns: var(--lab) 1fr; gap: 10px; align-items: center; font-size: 13px; color: var(--ink-2); height: 26px; }
.dbar .lab { text-align: right; white-space: nowrap; }
.dbar .track { position: relative; height: 16px; margin-right: 54px; }
.dbar .track i { position: absolute; left: 0; top: 0; bottom: 0; border-radius: 0 4px 4px 0; background: var(--base-soft); transition: width .6s cubic-bezier(.2, .7, .2, 1); }
.dbar.up .track i { background: var(--bv); }
.dbar .track b { position: absolute; top: 50%; transform: translate(4px, -50%); font-size: 12px; font-weight: 600; color: var(--ink-2); background: var(--surface); padding: 0 3px; border-radius: 3px; z-index: 1; font-variant-numeric: tabular-nums; white-space: nowrap; transition: left .6s cubic-bezier(.2, .7, .2, 1); }
.dbar.up .track b { color: var(--bv-deep); font-weight: 700; }
.dbar.up .lab { color: var(--ink); font-weight: 600; }
.dwrap { position: relative; }
.dref { position: absolute; top: 0; bottom: 20px; width: 0; left: calc(var(--lab) + 10px + (100% - var(--lab) - 10px - 54px) * 0.6667); border-left: 1.5px dashed var(--ink-3); pointer-events: none; }
.daxis { display: grid; grid-template-columns: var(--lab) 1fr; padding-right: 54px; gap: 10px; font-size: 11.5px; color: var(--ink-3); height: 20px; }
.daxis div { position: relative; }
.daxis span { position: absolute; top: 4px; transform: translateX(-50%); }

/* ------------------------------------------------------------------ human validation */
.hv { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.hv-card { background: var(--surface); border: 1px solid var(--rule); border-radius: var(--radius); padding: 20px 22px; font-family: var(--sans); box-shadow: var(--shadow); }
.hv-card h4 { margin: 0 0 2px; font-size: 16px; }
.hv-card .q { font-size: 13px; color: var(--ink-3); line-height: 1.5; margin-bottom: 14px; }
.ci { display: grid; grid-template-columns: 1fr; gap: 3px; margin-bottom: 14px; }
.ci .top { display: flex; justify-content: space-between; align-items: baseline; gap: 10px; font-size: 13.5px; color: var(--ink-2); }
.ci .top b { font-size: 22px; font-weight: 650; color: var(--ink); font-variant-numeric: tabular-nums; letter-spacing: -.01em; }
.ci .track { position: relative; height: 10px; background: var(--surface-2); border-radius: 5px; }
.ci .track i { position: absolute; top: 3px; height: 4px; border-radius: 2px; background: var(--ink-3); }
.ci .track u { position: absolute; top: -2px; width: 14px; height: 14px; margin-left: -7px; border-radius: 50%; background: var(--ink); border: 2.5px solid var(--surface); }
.ci.c-bv .track u { background: var(--bv); } .ci.c-bv .track i { background: var(--bv-soft); }
.ci .ends { display: flex; justify-content: space-between; font-size: 11px; color: var(--ink-3); }
.hv-foot { font-size: 12.5px; color: var(--ink-3); line-height: 1.5; border-top: 1px solid var(--rule-2); padding-top: 10px; }
.hv-foot b { color: var(--ink-2); }

/* ------------------------------------------------------------------ takeaway + cite + footer */
.takeaway { text-align: center; padding: 20px 0 6px; }
.takeaway blockquote { margin: 0 auto; max-width: 21em; font-size: clamp(25px, 3.6vw, 38px); line-height: 1.25; font-weight: 500; letter-spacing: -.015em; color: var(--ink); }
.takeaway p { color: var(--ink-2); max-width: 36em; margin: 18px auto 0; }
.bib { position: relative; background: var(--surface); border: 1px solid var(--rule); border-radius: 12px; padding: 18px 20px; overflow-x: auto; }
.bib pre { margin: 0; font: 13px/1.6 var(--mono); color: var(--ink-2); white-space: pre; }
.bib .mini-btn { position: absolute; top: 12px; right: 12px; }
footer { margin-top: 30px; padding: 30px 0 46px; border-top: 1px solid var(--rule); font-family: var(--sans); font-size: 13px; color: var(--ink-3); text-align: center; line-height: 1.7; }
footer a { color: var(--ink-2); }

.reveal { opacity: 0; transform: translateY(14px); transition: opacity .6s ease, transform .6s ease; }
.reveal.in { opacity: 1; transform: none; }
.sr-only { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }

/* ------------------------------------------------------------------ responsive */
@media (max-width: 1020px) {
  .topnav a { padding: 6px 7px; font-size: 13px; }
  .tasks { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}
@media (max-width: 860px) {
  .topnav { display: none; }
  .topbar .icon-btn { margin-left: auto; }
  .calc, .toy, .dial-top, .srfig, .case.on, .hv, .domains { grid-template-columns: 1fr; }
  .measure-grid { grid-template-columns: 1fr; }
  .readouts { grid-template-columns: repeat(3, 1fr); }
  .cmp-scroll { overflow-x: auto; }
}
@media (max-width: 560px) {
  body { font-size: 17px; }
  .hero { padding-top: 48px; }
  .hero h1 { white-space: normal; font-size: 36px; }
  .fig { padding: 16px 14px 14px; }
  .panels, .abl { grid-template-columns: 1fr; }
  .tes { grid-template-columns: 1fr; }
  .tasks { grid-template-columns: 1fr 1fr; }
  .bv-row { grid-template-columns: 1fr; }
  .bv-arrow { flex-direction: row; gap: 8px; }
  .bv-arrow svg { transform: rotate(90deg); width: 26px; }
  .readouts { grid-template-columns: 1fr; }
  .term { grid-template-columns: 1fr 1fr 42px; font-size: 12px; }
  .score { grid-template-columns: 118px 1fr 46px; }
  .domains { --lab: 118px; }
  .transfer { grid-template-columns: 1fr; }
  .t-arrow { transform: rotate(90deg); margin: 0 auto; }
  #toy-svg .ax-label { font-size: 19px; }
  .tpanel .ax text, .panel .ax text { font-size: 13.5px; }
  .cmp { font-size: 13px; }
  .sr-row { grid-template-columns: 1fr; justify-items: center; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .reveal { opacity: 1; transform: none; transition: none; }
  .toy-dot, .dbar .track i, .dbar .track b { transition: none; }
}