/* FewGaze. Concept: a gaze-calibration wall. The Columbia 7x3 fixation-dot grid is the motif; cobalt is
   the instrument ink, and the signal colour is reserved for one event, gaze lock. */
:root {
  --paper: #eef0ec;
  --paper-2: #e3e6e0;
  --card: #f7f8f5;
  --ink: #0f1218;
  --ink-2: #444a55;
  --ink-3: #737985;
  --rule: #cdd2cb;
  --rule-soft: #dde1da;
  --cobalt: #2a44f5;
  --cobalt-soft: rgba(42, 68, 245, 0.12);
  --signal: #ff4a1c;
  --s-geometry: #2a78d6;
  --s-dinov2: #eb6834;
  --s-l2cs: #1baf7a;
  --s-clip: #c98500;
  --heat-0: #e8ebe6;
  --heat-1: #2a44f5;
  --display: "Bricolage Grotesque", "Segoe UI", system-ui, sans-serif;
  --sans: "IBM Plex Sans", "Segoe UI", system-ui, sans-serif;
  --mono: "IBM Plex Mono", ui-monospace, Consolas, monospace;
  --wrap: 1180px;
  --gutter: clamp(16px, 4vw, 48px);
  --ease: cubic-bezier(.2, .7, .1, 1);
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --paper: #07090e; --paper-2: #0d1118; --card: #0f131b; --ink: #e9edf5; --ink-2: #a9b0bd; --ink-3: #747c8a;
    --rule: #242b37; --rule-soft: #171c25; --cobalt: #7088ff; --cobalt-soft: rgba(112, 136, 255, 0.14); --signal: #ff6a45;
    --s-geometry: #3987e5; --s-dinov2: #d95926; --s-l2cs: #199e70; --s-clip: #c98500; --heat-0: #131824; --heat-1: #7088ff;
    color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --paper: #07090e; --paper-2: #0d1118; --card: #0f131b; --ink: #e9edf5; --ink-2: #a9b0bd; --ink-3: #747c8a;
  --rule: #242b37; --rule-soft: #171c25; --cobalt: #7088ff; --cobalt-soft: rgba(112, 136, 255, 0.14); --signal: #ff6a45;
  --s-geometry: #3987e5; --s-dinov2: #d95926; --s-l2cs: #199e70; --s-clip: #c98500; --heat-0: #131824; --heat-1: #7088ff;
  color-scheme: dark;
}

*, *::before, *::after { box-sizing: border-box; }
[hidden] { display: none !important; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body { margin: 0; background: var(--paper); color: var(--ink); font: 16px/1.6 var(--sans); overflow-x: hidden; }
a { color: inherit; text-underline-offset: 3px; }
:focus-visible { outline: 2px solid var(--cobalt); outline-offset: 3px; }
.skip { position: absolute; left: -999px; top: 8px; background: var(--ink); color: var(--paper); padding: 8px 12px; z-index: 50; }
.skip:focus { left: 8px; }
.visually-hidden { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }
.mono, code, pre { font-family: var(--mono); }
.muted { color: var(--ink-3); }
.small { font-size: 13px; }
h1, h2, h3 { font-family: var(--display); font-weight: 600; letter-spacing: -0.02em; text-wrap: balance; margin: 0; }

/* ---------- top bar ---------- */
.bar {
  position: fixed; inset: 0 0 auto 0; z-index: 20; display: flex; align-items: center; gap: 24px;
  padding: calc(env(safe-area-inset-top, 0px) + 12px) var(--gutter) 12px;
  background: color-mix(in srgb, var(--paper) 78%, transparent); backdrop-filter: blur(10px);
  border-bottom: 1px solid transparent; transition: border-color .3s;
}
.bar.scrolled { border-bottom-color: var(--rule); }
.brand { display: inline-flex; align-items: center; gap: 10px; font: 700 18px var(--display); text-decoration: none; letter-spacing: -0.01em; }
.brand-mark { width: 18px; height: 18px; border-radius: 50%; border: 3px solid var(--cobalt); position: relative; }
.brand-mark::after { content: ""; position: absolute; inset: 3px; border-radius: 50%; background: var(--signal); }
.nav { display: none; gap: 22px; margin-left: auto; font-size: 14px; color: var(--ink-2); }
.nav a { text-decoration: none; }
.nav a:hover { color: var(--ink); }
@media (min-width: 920px) { .nav { display: flex; } }
.theme { margin-left: auto; width: 36px; height: 36px; border-radius: 50%; border: 1px solid var(--rule); background: transparent; cursor: pointer; display: grid; place-items: center; }
@media (min-width: 920px) { .theme { margin-left: 0; } }
.theme span { width: 14px; height: 14px; border-radius: 50%; background: linear-gradient(90deg, var(--ink) 50%, transparent 50%); border: 1.5px solid var(--ink); }

/* ---------- buttons ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px; min-height: 44px; padding: 0 18px;
  border: 1.5px solid var(--ink); border-radius: 999px; background: transparent; color: var(--ink);
  font: 500 15px var(--sans); text-decoration: none; cursor: pointer; transition: transform .2s var(--ease), background .2s, color .2s;
}
.btn:hover { transform: translateY(-1px); }
.btn.primary { background: var(--cobalt); border-color: var(--cobalt); color: #fff; }
.btn:disabled { opacity: .45; cursor: not-allowed; transform: none; }

/* ---------- hero ---------- */
.hero { position: relative; min-height: min(92svh, 900px); display: grid; align-items: end; padding: 120px var(--gutter) 56px; overflow: hidden; isolation: isolate; }
.hero-canvas { position: absolute; inset: 0; width: 100%; height: 100%; z-index: -1; }
.hero-grid { position: absolute; inset: 0; z-index: -2; pointer-events: none; }
.hero-grid i { position: absolute; width: 10px; height: 10px; margin: -5px 0 0 -5px; border-radius: 50%; background: var(--rule); transition: background .25s, transform .25s; }
.hero-grid i.near { background: var(--cobalt); transform: scale(1.6); }
.hero-grid i.centre { background: transparent; border: 2px solid var(--ink-3); width: 18px; height: 18px; margin: -9px 0 0 -9px; }
.hero-grid i.centre.lock { border-color: var(--signal); box-shadow: 0 0 0 10px color-mix(in srgb, var(--signal) 18%, transparent); }
.hero-copy { max-width: 760px; position: relative; }
.kicker { font: 500 13px var(--mono); letter-spacing: 0.06em; text-transform: uppercase; color: var(--ink-2); margin: 0 0 18px; }
.hero h1 { font-size: clamp(56px, 11vw, 148px); line-height: 0.88; font-weight: 700; letter-spacing: -0.045em; }
.hero h1 .h1-line { display: inline-block; }
.hero h1 em { font-style: normal; color: var(--cobalt); font-weight: 300; }
.lede { font-size: clamp(17px, 2vw, 20px); max-width: 56ch; color: var(--ink-2); margin: 24px 0 28px; }
.cta { display: flex; flex-wrap: wrap; gap: 10px; }
.hud {
  position: absolute; right: var(--gutter); top: 110px; display: grid; gap: 6px; padding: 14px 16px; min-width: 210px;
  border: 1px solid var(--rule); background: color-mix(in srgb, var(--card) 80%, transparent); backdrop-filter: blur(6px); font: 13px var(--mono);
}
.hud > div { display: flex; justify-content: space-between; gap: 16px; }
.hud-k { color: var(--ink-3); }
.hud-v { font-variant-numeric: tabular-nums; }
.hud-lock { justify-content: center !important; margin-top: 4px; padding: 4px; color: var(--ink-3); border: 1px dashed var(--rule); text-transform: uppercase; letter-spacing: .1em; font-size: 11px; transition: all .2s; }
.hud.lock .hud-lock { color: #fff; background: var(--signal); border-color: var(--signal); }
.hud.lock #hud-label { color: var(--signal); }
@media (max-width: 760px) {
  .hud { top: auto; bottom: 16px; right: 16px; min-width: 0; font-size: 11px; padding: 8px 10px; }
  .hero { padding-top: calc(84px + 4.8 * min(100vw / 8.5, 70px) + 40px); padding-bottom: 150px; align-items: start; }
}
.hero-hint { position: absolute; left: 50%; bottom: 14px; transform: translateX(-50%); margin: 0; font: 12px var(--mono); color: var(--ink-3); white-space: nowrap; }
@media (max-width: 760px) { .hero-hint { display: none; } }

/* ---------- numbers ---------- */
.numbers { display: grid; grid-template-columns: repeat(auto-fit, minmax(170px, 1fr)); border-block: 1px solid var(--rule); }
.num { padding: 28px var(--gutter) 26px; border-right: 1px solid var(--rule); }
.num:last-child { border-right: 0; }
.num b { display: block; font: 600 clamp(36px, 5vw, 56px)/1 var(--display); letter-spacing: -0.03em; font-variant-numeric: tabular-nums; }
.num span { display: block; margin-top: 8px; font-size: 13px; color: var(--ink-2); max-width: 24ch; }

/* ---------- sections ---------- */
.sec { max-width: var(--wrap); margin: 0 auto; padding: clamp(72px, 10vw, 140px) var(--gutter) 0; }
.sec-head { max-width: 860px; margin-bottom: 28px; }
.eyebrow { font: 500 12px var(--mono); letter-spacing: .1em; text-transform: uppercase; color: var(--cobalt); margin: 0 0 14px; }
.sec h2 { font-size: clamp(32px, 5vw, 60px); line-height: 1.02; }
.sec-lede { max-width: 66ch; font-size: 18px; color: var(--ink-2); margin: 0 0 32px; }
.placeholder { border: 1px dashed var(--rule); padding: 32px; color: var(--ink-3); text-align: center; }

/* ---------- 5 degree problem ---------- */
.problem { display: grid; grid-template-columns: 1fr; gap: 32px; align-items: center; }
@media (min-width: 900px) { .problem { grid-template-columns: 1.25fr 1fr; } }
.problem > * { min-width: 0; }
.eye-stage { background: var(--card); border: 1px solid var(--rule); padding: 18px; }
#eye-svg { width: 100%; height: auto; display: block; }
.slider { display: grid; gap: 8px; margin-top: 10px; }
.slider label { font: 500 14px var(--mono); display: flex; justify-content: space-between; }
.slider output { color: var(--cobalt); font-variant-numeric: tabular-nums; }
.slider input { width: 100%; accent-color: var(--cobalt); }
.ticks { display: flex; justify-content: space-between; font: 11px var(--mono); color: var(--ink-3); }
.big-stat { display: flex; align-items: baseline; gap: 14px; margin: 18px 0; }
.big-stat b { font: 600 clamp(36px, 5vw, 54px)/1 var(--display); letter-spacing: -0.03em; color: var(--cobalt); font-variant-numeric: tabular-nums; min-width: 4ch; }
.big-stat span { color: var(--ink-2); font-size: 15px; }
.heat-wrap { margin-top: 56px; }
.heat-wrap h3 { font-size: 24px; margin-bottom: 6px; }
.heat { display: grid; grid-template-columns: 52px repeat(7, minmax(0, 1fr)); gap: 6px; margin-top: 18px; max-width: 820px; }
.heat .hc { aspect-ratio: 1.35; display: grid; place-items: center; font: 500 clamp(11px, 1.6vw, 15px) var(--mono); border-radius: 4px; background: var(--heat-0); color: var(--ink); transform: scale(.85); opacity: 0; transition: transform .6s var(--ease), opacity .6s, background .6s; }
.heat.in .hc { transform: none; opacity: 1; }
.heat .hc.pos { outline: 2.5px solid var(--signal); outline-offset: 2px; }
.heat .hl { display: grid; place-items: center; font: 11px var(--mono); color: var(--ink-3); }

/* ---------- charts ---------- */
.chart-card { background: var(--card); border: 1px solid var(--rule); padding: clamp(16px, 2.4vw, 28px); margin-bottom: 24px; min-width: 0; }
.chart-card h3 { font-size: 20px; margin-bottom: 10px; }
.chart-top { display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 14px; margin-bottom: 10px; }
.seg { display: inline-flex; border: 1px solid var(--rule); border-radius: 999px; padding: 3px; gap: 2px; }
.seg button { border: 0; background: none; padding: 6px 14px; border-radius: 999px; font: 500 13px var(--sans); color: var(--ink-2); cursor: pointer; }
.seg button[aria-pressed="true"] { background: var(--ink); color: var(--paper); }
.legend { display: flex; flex-wrap: wrap; gap: 4px 16px; font-size: 13px; color: var(--ink-2); }
.legend span { display: inline-flex; align-items: center; gap: 6px; }
.legend i { width: 18px; border-top: 2.5px solid; }
.legend i.dash { border-top-style: dashed; }
.chart { position: relative; width: 100%; }
.chart svg { display: block; width: 100%; height: auto; overflow: visible; }
.chart text { fill: var(--ink-3); font: 11px var(--mono); }
.chart .grid line { stroke: var(--rule-soft); }
.chart .chance { stroke: var(--ink-3); stroke-dasharray: 2 4; }
.chart .draw { stroke-dasharray: var(--len); stroke-dashoffset: var(--len); transition: stroke-dashoffset 1.6s var(--ease); }
.chart.in .draw { stroke-dashoffset: 0; }
.chart .fade { opacity: 0; transition: opacity 1s .5s; }
.chart.in .fade { opacity: 1; }
.caption { font-size: 13px; color: var(--ink-3); margin: 10px 0 0; max-width: 78ch; }
.tooltip { position: absolute; pointer-events: none; background: var(--ink); color: var(--paper); font: 12px/1.45 var(--mono); padding: 8px 10px; border-radius: 4px; white-space: nowrap; transform: translate(-50%, calc(-100% - 12px)); opacity: 0; transition: opacity .12s; z-index: 5; }
.tooltip.on { opacity: 1; }
@media (max-width: 640px) { .chart { overflow-x: auto; } .chart svg { min-width: 560px; } }
.facts { display: grid; grid-template-columns: repeat(auto-fit, minmax(210px, 1fr)); gap: 0; border-top: 1px solid var(--rule); margin: 8px 0 32px; }
.fact { padding: 22px 18px 22px 0; border-bottom: 1px solid var(--rule); }
.fact b { display: block; font: 600 clamp(32px, 4vw, 46px)/1 var(--display); letter-spacing: -0.03em; font-variant-numeric: tabular-nums; }
.fact span { display: block; margin-top: 8px; font-size: 14px; color: var(--ink-2); max-width: 30ch; }
.two { display: grid; grid-template-columns: 1fr; gap: 24px; }
@media (min-width: 900px) { .two { grid-template-columns: 1fr 1fr; } }
.two > * { min-width: 0; }

/* ---------- study 2 grid ---------- */
.s2grid { display: grid; gap: 14px; overflow-x: auto; }
.s2row { display: grid; grid-template-columns: 150px repeat(13, minmax(26px, 1fr)); gap: 3px; align-items: center; min-width: 560px; }
.s2row .lab { font: 12px var(--mono); color: var(--ink-2); padding-right: 8px; }
.s2row .lab b { display: block; font: 600 14px var(--display); color: var(--ink); }
.s2row .c { aspect-ratio: 1.2; border-radius: 3px; background: var(--heat-0); display: grid; place-items: center; font: 10px var(--mono); color: transparent; transition: background .8s var(--ease), color .3s; }
.s2row .c:hover { color: var(--ink); outline: 1px solid var(--ink-3); }
.s2row.axis .c { background: none; color: var(--ink-3); aspect-ratio: auto; }
.s2key { display: flex; align-items: center; gap: 10px; font: 12px var(--mono); color: var(--ink-3); margin-top: 6px; flex-wrap: wrap; }
.s2key .ramp { height: 10px; width: 160px; background: linear-gradient(90deg, var(--heat-0), var(--heat-1)); border-radius: 2px; }

/* ---------- demo ---------- */
.demo { display: grid; grid-template-columns: 1fr; gap: 20px; }
@media (min-width: 980px) { .demo { grid-template-columns: 1.35fr 1fr; } }
.demo > * { min-width: 0; }
.stage { position: relative; aspect-ratio: 4 / 3; background: var(--paper-2); border: 1px solid var(--rule); overflow: hidden; display: grid; place-items: center; }
.stage video { position: absolute; width: 1px; height: 1px; opacity: 0; pointer-events: none; }
.stage canvas { position: absolute; inset: 0; width: 100%; height: 100%; }
.stage-empty { text-align: center; position: relative; z-index: 1; padding: 16px; }
.stage-empty p { margin: 6px 0; }
.lens { width: 88px; height: 88px; margin: 0 auto 18px; border-radius: 50%; border: 2px solid var(--ink-3); display: grid; place-items: center; animation: breathe 3.2s ease-in-out infinite; }
.lens i { width: 26px; height: 26px; border-radius: 50%; background: var(--cobalt); box-shadow: 0 0 0 10px var(--cobalt-soft); }
@keyframes breathe { 50% { transform: scale(1.08); } }
.stage-lock { position: absolute; top: 14px; left: 14px; padding: 6px 12px; font: 600 12px var(--mono); letter-spacing: .1em; text-transform: uppercase; background: var(--signal); color: #fff; border-radius: 999px; opacity: 0; transform: translateY(-6px); transition: all .25s var(--ease); z-index: 2; }
.stage.lock .stage-lock { opacity: 1; transform: none; }
.stage.lock { box-shadow: inset 0 0 0 3px var(--signal); }
.panel { background: var(--card); border: 1px solid var(--rule); padding: 20px; }
.controls { display: flex; flex-wrap: wrap; gap: 8px; }
.status { font-size: 14px; color: var(--ink-2); min-height: 1.6em; margin: 12px 0 6px; }
.status[data-kind="error"] { color: var(--signal); font-weight: 500; }
.gauge-wrap { display: grid; grid-template-columns: 1fr; justify-items: center; }
.gauge { width: 100%; max-width: 300px; height: auto; overflow: visible; }
.g-track, .g-fill { fill: none; stroke-width: 16; }
.g-track { stroke-linecap: round; }
.g-fill { stroke-linecap: butt; }
.g-track { stroke: var(--rule-soft); }
.g-fill { stroke: var(--cobalt); stroke-dasharray: 0 100; transition: stroke-dasharray .25s var(--ease), stroke .25s; }
.gauge.lock .g-fill { stroke: var(--signal); }
.g-thr { stroke: var(--ink-3); stroke-width: 2; }
.g-needle { stroke: var(--ink); stroke-width: 3; stroke-linecap: round; transform-origin: 120px 120px; transform: rotate(-90deg); transition: transform .25s var(--ease); }
.g-hub { fill: var(--ink); }
.gauge-read { text-align: center; margin-top: -8px; }
.gauge-read b { display: block; font: 600 54px/1 var(--display); letter-spacing: -0.03em; font-variant-numeric: tabular-nums; }
.gauge-read span { font-size: 14px; color: var(--ink-2); }
.spark { width: 100%; height: 56px; margin-top: 12px; display: block; }
.spark polyline { fill: none; stroke: var(--cobalt); stroke-width: 2; vector-effect: non-scaling-stroke; }
.s-thr { stroke: var(--ink-3); stroke-dasharray: 3 4; vector-effect: non-scaling-stroke; }
.spark-cap { margin-top: 2px; }
.checks { list-style: none; padding: 0; margin: 14px 0 0; display: grid; gap: 8px; font-size: 13px; color: var(--ink-2); }
.checks li { padding-left: 22px; position: relative; }
.checks li::before { position: absolute; left: 2px; font-weight: 700; }
.checks li[data-kind="ok"]::before { content: "✓"; color: var(--s-l2cs); }
.checks li[data-kind="warn"]::before { content: "!"; color: var(--signal); left: 6px; }
.measure { margin-top: 14px; }
.measure summary { cursor: pointer; font-weight: 500; font-size: 14px; }
.table-scroll { overflow-x: auto; }
table { border-collapse: collapse; width: 100%; font-size: 13px; }
th, td { text-align: left; padding: 7px 10px 7px 0; border-bottom: 1px solid var(--rule-soft); }
th { font: 500 11px var(--mono); color: var(--ink-3); text-transform: uppercase; letter-spacing: .06em; }
td.num, th.num { text-align: right; font-variant-numeric: tabular-nums; white-space: nowrap; }
td:first-child { white-space: nowrap; }
tr.out td { color: var(--signal); }

/* ---------- method ---------- */
.steps { display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); gap: 0; border-top: 1px solid var(--rule); }
.step { padding: 26px 22px 26px 0; border-bottom: 1px solid var(--rule); }
.step-n { font: 500 12px var(--mono); color: var(--cobalt); }
.step h3 { font-size: 22px; margin: 10px 0 6px; }
.step p { margin: 0; color: var(--ink-2); font-size: 15px; }
.limits { margin-top: 48px; padding: 28px; border: 1.5px solid var(--ink); }
.limits h3 { font-size: 24px; margin-bottom: 12px; }
.limits ul { margin: 0; padding: 0; list-style: none; display: grid; gap: 10px; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); }
.limits li { font-size: 15px; color: var(--ink-2); }
.limits b { color: var(--ink); display: block; }
pre { background: var(--card); border: 1px solid var(--rule); padding: 18px; overflow-x: auto; font-size: 13px; line-height: 1.7; margin: 0; }
.foot { max-width: var(--wrap); margin: 0 auto; padding: 64px var(--gutter) calc(48px + env(safe-area-inset-bottom, 0px)); font-size: 13px; color: var(--ink-3); }

/* ---------- motion ---------- */
.reveal { opacity: 0; transform: translateY(24px); transition: opacity .9s var(--ease), transform .9s var(--ease); }
.reveal.in { opacity: 1; transform: none; }
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .reveal, .heat .hc, .chart .draw, .chart .fade { transition: none !important; opacity: 1 !important; transform: none !important; stroke-dashoffset: 0 !important; }
  .lens { animation: none; }
}