/* Reliability-Guided Fusion — an interactive paper. Ink on matte paper; no colour. */
@font-face { font-family: "Mogaly"; src: url("fonts/Mogaly.otf") format("opentype"); font-display: swap; }

:root {
  --paper: #f5f4f0;
  --paper-2: #ebeae5;            /* recessed areas: inputs, readouts */
  --ink: #161513;
  --ink-2: #47443e;
  --ink-3: #85806f;
  --rule: rgba(22, 21, 19, 0.82);
  --rule-2: rgba(22, 21, 19, 0.22);
  --rule-3: rgba(22, 21, 19, 0.10);
  --display: "Mogaly", "Charter", Georgia, serif;
  --serif: Charter, "Bitstream Charter", "Iowan Old Style", Georgia, serif;
  --mono: ui-monospace, "SF Mono", "JetBrains Mono", Menlo, monospace;
  --measure: 620px;
  --margin: 230px;
}
:root[data-theme="dark"] {
  --paper: #1b1a17;
  --paper-2: #23221e;
  --ink: #e7e2d6;
  --ink-2: #b4ae9f;
  --ink-3: #7b766a;
  --rule: rgba(231, 226, 214, 0.78);
  --rule-2: rgba(231, 226, 214, 0.20);
  --rule-3: rgba(231, 226, 214, 0.08);
}

* { box-sizing: border-box; }
[hidden] { display: none !important; }
html { scroll-behavior: smooth; scroll-padding-top: 64px;
  /* Friction: near a step the page settles on it, and a hard flick cannot skip over one. */
  scroll-snap-type: y proximity; }
body {
  margin: 0; background: var(--paper); color: var(--ink);
  font-family: var(--serif); font-size: 18px; line-height: 1.58;
  -webkit-font-smoothing: antialiased; text-rendering: optimizeLegibility;
  font-variant-numeric: oldstyle-nums proportional-nums;
  transition: background-color .35s ease, color .35s ease;
}
/* paper texture: a seamless tile of tooth, mottling and fibres in pure black/white at low
   alpha (showcase/make_paper_texture.py), so it never tints the paper colour */
body { background-image: url("textures/paper-light.png"); background-size: 512px 512px; }
:root[data-theme="dark"] body { background-image: url("textures/paper-dark.png"); }
::selection { background: var(--ink); color: var(--paper); }
a { color: inherit; text-decoration-thickness: 1px; text-underline-offset: 3px; }
a:hover { text-decoration-thickness: 2px; }
button, input, textarea { font: inherit; color: inherit; }
.mono, .num { font-family: var(--mono); font-size: 0.82em; font-variant-numeric: tabular-nums; letter-spacing: -0.01em; }
.sc { font-variant: small-caps; letter-spacing: 0.06em; text-transform: lowercase; }
.muted { color: var(--ink-2); }
.faint { color: var(--ink-3); }

/* ── top bar ──────────────────────────────────────────── */
.bar {
  position: sticky; top: 0; z-index: 50; background-color: var(--paper); background-image: inherit; background-size: 512px 512px;
  border-bottom: 1px solid var(--rule); display: flex; align-items: center; gap: 28px;
  padding: 0 32px; height: 52px; transition: background-color .35s ease;
}
.bar .title { font-family: var(--display); font-size: 19px; white-space: nowrap; text-decoration: none; }
.bar nav { display: flex; gap: 20px; margin-left: auto; font-size: 15px; }
.bar nav a { text-decoration: none; color: var(--ink-2); white-space: nowrap; }
.bar nav a:hover, .bar nav a.on { color: var(--ink); text-decoration: underline; }
.bar nav a span { font-family: var(--mono); font-size: 12px; margin-right: 4px; }
.theme { border: 1px solid var(--rule); background: none; padding: 3px 10px; cursor: pointer; font-family: var(--mono); font-size: 12px; }
.theme:hover { background: var(--ink); color: var(--paper); }

/* ── page frame ───────────────────────────────────────── */
.page { max-width: calc(var(--measure) + var(--margin) * 2 + 120px); margin: 0 auto; padding: 0 32px; }
.col { max-width: var(--measure); margin-left: calc(var(--margin) + 40px); position: relative; }
p { margin: 0 0 1.05em; hyphens: auto; }
em { font-style: italic; }

/* sidenotes (Tufte) */
.sn { position: absolute; right: calc(100% + 36px); width: var(--margin); font-size: 13.5px; line-height: 1.45; color: var(--ink-2); margin-top: 0.25em; }
.sn::before { content: attr(data-n); font-family: var(--mono); font-size: 10.5px; margin-right: 5px; vertical-align: 2px; }
sup.ref { font-family: var(--mono); font-size: 10.5px; line-height: 0; }

/* ── title block ──────────────────────────────────────── */
.masthead { padding: 76px 0 40px; border-bottom: 1px solid var(--rule); }
.masthead .kicker { font-size: 15px; color: var(--ink-2); }
.masthead h1 { font-family: var(--display); font-weight: 400; font-size: clamp(46px, 6.2vw, 84px); line-height: 1.02; letter-spacing: -0.005em; margin: 22px 0 18px; max-width: 15ch; }
.masthead .subtitle { font-style: italic; font-size: 21px; color: var(--ink-2); max-width: 40ch; margin: 0 0 34px; }
.authors { display: grid; grid-template-columns: repeat(4, auto) 1fr; gap: 6px 34px; font-size: 16px; padding-top: 18px; border-top: 1px solid var(--rule-2); }
.authors div span { display: block; }
.authors .guide { justify-self: end; text-align: right; }
.abstract { display: grid; grid-template-columns: var(--margin) minmax(0, var(--measure)); gap: 40px; padding: 40px 0 8px; }
.abstract h2 { font-family: var(--display); font-weight: 400; font-size: 22px; margin: 0; }
.abstract p { font-size: 18.5px; }
.jump { font-size: 15px; display: flex; gap: 24px; margin-top: 6px; }

/* ── sections ─────────────────────────────────────────── */
section.chapter { padding: 90px 0 30px; border-bottom: 1px solid var(--rule-2); }
.chapter-head { display: grid; grid-template-columns: var(--margin) minmax(0, var(--measure)); gap: 40px; margin-bottom: 26px; }
.chapter-head .no { font-family: var(--mono); font-size: 13px; color: var(--ink-3); padding-top: 18px; border-top: 1px solid var(--rule); }
.chapter-head h2 { font-family: var(--display); font-weight: 400; font-size: clamp(34px, 3.6vw, 48px); line-height: 1.06; margin: 0; padding-top: 10px; border-top: 1px solid var(--rule); }
.chapter-head .lede { grid-column: 2; font-size: 20px; color: var(--ink-2); font-style: italic; margin: 0; }

/* ── scrollytelling ───────────────────────────────────── */
.scrolly { display: grid; grid-template-columns: minmax(300px, 400px) minmax(0, 1fr); gap: 64px; position: relative; }
.steps { padding: 6vh 0 18vh; }
.step { min-height: 46vh; display: flex; flex-direction: column; justify-content: center; opacity: 0.5; transition: opacity .45s ease; padding: 3vh 0; }
.step { scroll-snap-align: center; scroll-snap-stop: always; }
.step.on { opacity: 1; }
.step .k { font-family: var(--mono); font-size: 12px; color: var(--ink-3); margin-bottom: 10px; }
.step h3 { font-family: var(--display); font-weight: 400; font-size: 26px; line-height: 1.15; margin: 0 0 6px; }
.step .sub { font-style: italic; color: var(--ink-2); font-size: 16px; margin: 0 0 14px; }
.step p { font-size: 17.5px; }
.stage { position: sticky; top: 76px; height: calc(100vh - 100px); display: flex; flex-direction: column; justify-content: center; }
.figure { border-top: 1px solid var(--rule); border-bottom: 1px solid var(--rule); padding: 18px 0 14px; position: relative; }
.figure svg { display: block; width: 100%; height: auto; overflow: visible; }
.cap { font-size: 14px; line-height: 1.45; color: var(--ink-2); margin-top: 12px; }
.cap b { font-variant: small-caps; letter-spacing: .05em; color: var(--ink); font-weight: 400; }

/* svg ink conventions */
.ink { stroke: var(--ink); fill: none; stroke-width: 1.2; }
.ink-f { fill: var(--ink); }
.ink-t { fill: var(--ink); font-family: var(--serif); }
.ink-m { fill: var(--ink-2); font-family: var(--mono); }
.ink-soft { stroke: var(--rule-2); fill: none; }
.paper-f { fill: var(--paper); }
.layer { transition: opacity .55s ease; }
.layer.off { opacity: 0; pointer-events: none; }
.layer.dim { opacity: 0.22; }
.draw { transition: stroke-dashoffset 1.1s cubic-bezier(.6,.1,.3,1); }

/* expert patterns for HTML elements (svg uses <pattern> defs) */
.p-img { background: var(--ink); }
.p-txt { background: repeating-linear-gradient(-45deg, var(--ink) 0 1.3px, transparent 1.3px 4.6px); }
.p-int { background: radial-gradient(circle, var(--ink) 1.15px, transparent 1.35px) 0 0 / 5px 5px; }
.sw { display: inline-block; width: 13px; height: 13px; border: 1px solid var(--ink); vertical-align: -2px; margin-right: 6px; }
.key { display: flex; gap: 22px; flex-wrap: wrap; font-size: 14px; color: var(--ink-2); }

/* stacked π bar */
.pibar { display: flex; height: 26px; border: 1px solid var(--ink); }
.pibar i { display: block; height: 100%; transition: width .8s cubic-bezier(.6,.1,.3,1); border-right: 1px solid var(--ink); }
.pibar i:last-child { border-right: 0; }
.pilab { display: flex; justify-content: space-between; margin-top: 6px; }

/* ── §4 instrument ────────────────────────────────────── */
.instrument { border: 1px solid var(--rule); margin-top: 8px; display: grid; grid-template-columns: minmax(300px, 0.85fr) minmax(0, 1.4fr); }
.instrument > div { padding: 26px 28px 28px; }
.instrument .in { border-right: 1px solid var(--rule); }
.lbl { font-variant: small-caps; text-transform: lowercase; letter-spacing: .07em; font-size: 15px; color: var(--ink-2); margin: 0 0 10px; display: flex; justify-content: space-between; }
.photo { position: relative; aspect-ratio: 4 / 3; border: 1px dashed var(--rule); background: var(--paper-2); display: grid; place-items: center; cursor: pointer; overflow: hidden; }
.photo:hover, .photo.over { border-style: solid; }
/* the only colour on the page: uploaded photos, muted like a print on matte paper */
.photo img { position: absolute; inset: 0; width: 100%; height: 100%; object-fit: cover;
  filter: saturate(.52) sepia(.08) contrast(.96) brightness(1.03); mix-blend-mode: multiply; }
:root[data-theme="dark"] .photo img { mix-blend-mode: normal; filter: saturate(.48) sepia(.06) contrast(.95) brightness(.88); }
.photo .ph { text-align: center; font-size: 15px; color: var(--ink-2); padding: 20px; }
.photo .ph .mono { display: block; margin-top: 6px; color: var(--ink-3); }
.photo .swap { position: absolute; right: 0; bottom: 0; background: var(--paper); border-top: 1px solid var(--rule); border-left: 1px solid var(--rule); padding: 3px 10px; font-size: 13px; }
textarea { width: 100%; min-height: 84px; resize: vertical; margin-top: 18px; padding: 10px 12px; border: 1px solid var(--rule); background: var(--paper-2); line-height: 1.45; font-size: 16.5px; outline: none; }
textarea:focus { outline: 2px solid var(--ink); outline-offset: -2px; }
.tries { font-size: 14.5px; margin-top: 10px; color: var(--ink-2); line-height: 1.7; }
.tries button { background: none; border: 0; padding: 0; cursor: pointer; text-decoration: underline; text-decoration-color: var(--rule-2); text-underline-offset: 3px; }
.tries button:hover { text-decoration-color: var(--ink); }
.tryrow { display: flex; align-items: flex-start; gap: 16px; }
.tryrow .tries { flex: 1; }
.clear { flex: none; margin-top: 12px; border: 1px solid var(--rule); background: none; padding: 3px 10px; cursor: pointer; font-family: var(--mono); font-size: 12px; }
.clear:hover:not(:disabled) { background: var(--ink); color: var(--paper); }
.clear:disabled { opacity: 0.35; cursor: default; }

/* static build: a row of recorded examples in place of upload */
.exrow { display: grid; grid-template-columns: repeat(3, 1fr); gap: 10px; margin-top: 12px; flex: 1; }
.exrow button { background: none; border: 1px solid var(--rule-2); padding: 0; cursor: pointer; text-align: left; font-size: 13.5px; line-height: 1.25; }
.exrow button img { display: block; width: 100%; aspect-ratio: 4 / 3; object-fit: cover; border-bottom: 1px solid var(--rule-2); }
.exrow button span { display: block; padding: 5px 7px 6px; }
.exrow button:hover { border-color: var(--ink); }
.exrow button.on { border-color: var(--ink); background: var(--ink); color: var(--paper); }

/* live flow: the five stages of one prediction, lit in order with the real numbers */
.flowwrap { container-type: inline-size; margin-bottom: 26px; }
.flowwrap .lbl { align-items: center; }
.replay { margin-top: 0; font-variant: normal; text-transform: none; letter-spacing: 0; }
.flow { display: grid; grid-template-columns: 0.95fr 1fr 1.55fr 1.2fr 0.95fr; border: 1px solid var(--rule); font-size: 13.5px; line-height: 1.35; }
.flow .st { position: relative; padding: 10px 10px 12px 14px; border-left: 1px solid var(--rule-2); opacity: .22; transition: opacity .45s ease; min-width: 0; }
.flow .st:first-child { border-left: 0; }
.flow .st.lit { opacity: 1; }
.flow .st + .st::before { content: "›"; position: absolute; left: -7px; top: 50%; transform: translateY(-50%); width: 13px; text-align: center; background-color: var(--paper); font-family: var(--mono); font-size: 14px; line-height: 18px; color: var(--ink); }
.flow .h { font-variant: small-caps; text-transform: lowercase; letter-spacing: .06em; color: var(--ink-3); margin-bottom: 8px; white-space: nowrap; }
.flow .h b { font-family: var(--mono); font-weight: 400; font-size: 11px; margin-right: 6px; font-variant: normal; }
.flow .thumb { width: 100%; max-width: 92px; aspect-ratio: 1; border: 1px solid var(--rule); overflow: hidden; display: flex; align-items: center; justify-content: center; }
.flow .thumb img { width: 100%; height: 100%; object-fit: cover; display: block; }
.flow .none { color: var(--ink-3); font-family: var(--mono); font-size: 11px; background: repeating-linear-gradient(45deg, var(--rule-3) 0 1px, transparent 1px 6px); }
.flow .cap2 { margin-top: 7px; font-style: italic; display: -webkit-box; -webkit-line-clamp: 3; -webkit-box-orient: vertical; overflow: hidden; }
.flow .cap2.none { font-style: normal; padding: 3px 6px; border: 1px solid var(--rule-2); display: inline-block; }
.flow .feat { padding: 4px 0; border-bottom: 1px solid var(--rule-3); }
.flow .feat:last-child { border-bottom: 0; }
.flow .ex { display: grid; grid-template-columns: 14px 1fr auto; column-gap: 6px; align-items: center; padding: 3px 0 6px; }
.flow .ex .sw { margin: 0; }
.flow .ex .g { text-transform: capitalize; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.flow .sure, .flow .wb { display: block; height: 6px; border: 1px solid var(--rule-2); position: relative; }
.flow .sure { grid-column: 2 / 4; margin-top: 3px; }
.flow .sure i, .flow .wb i { position: absolute; inset: 0 auto 0 0; width: 0; transition: width .7s cubic-bezier(.6,.1,.3,1); }
.flow .sure i { background: var(--ink-2); }
.flow .w { display: grid; grid-template-columns: 1fr auto; column-gap: 6px; align-items: baseline; padding: 2px 0 7px; }
.flow .wb { grid-column: 1 / 3; height: 10px; border-color: var(--ink); margin-top: 3px; }
.flow .ans { font-family: var(--display); font-size: 17.5px; line-height: 1.12; text-transform: capitalize; margin-bottom: 4px; overflow-wrap: break-word; }
.flow .hint { color: var(--ink-3); font-size: 12px; margin-top: 6px; }
@container (max-width: 600px) {
  .flow { grid-template-columns: 1fr; }
  .flow .st { border-left: 0; border-top: 1px solid var(--rule-2); display: grid; grid-template-columns: 104px 1fr; column-gap: 12px; padding: 12px; }
  .flow .st:first-child { border-top: 0; }
  .flow .st > .h { grid-column: 1; grid-row: 1 / span 6; white-space: normal; }
  .flow .st > :not(.h) { grid-column: 2; }
  .flow .st + .st::before { content: "⌄"; left: 50%; top: -10px; transform: translateX(-50%); }
}
@media (prefers-reduced-motion: reduce) { .flow .st, .flow .sure i, .flow .wb i { transition: none; } }
.go { margin-top: 20px; width: 100%; padding: 12px 16px; background: var(--ink); color: var(--paper); border: 1px solid var(--ink); cursor: pointer; font-size: 17px; letter-spacing: .02em; display: flex; justify-content: space-between; align-items: center; }
.go:hover:not(:disabled) { background: var(--paper); color: var(--ink); }
.go:disabled { opacity: .35; cursor: not-allowed; }
.go .mono { opacity: .8; }
.status { margin-top: 14px; font-size: 12.5px; color: var(--ink-3); line-height: 1.5; }
.status b { color: var(--ink); font-weight: 400; }
.err { margin-top: 10px; font-size: 14px; border-left: 2px solid var(--ink); padding-left: 10px; }

.out .blank { height: 100%; min-height: 420px; display: grid; place-items: center; text-align: center; color: var(--ink-3); font-style: italic; }
.verdict { display: grid; grid-template-columns: 1fr auto; align-items: end; gap: 12px; padding-bottom: 16px; border-bottom: 1px solid var(--rule); }
.verdict .what { font-family: var(--display); font-size: 44px; line-height: 1; text-transform: capitalize; }
.verdict .p { font-family: var(--mono); font-size: 26px; }
.verdict .vs { grid-column: 1 / -1; font-size: 15px; color: var(--ink-2); }
.verdict .vs b { font-weight: 400; color: var(--ink); text-transform: capitalize; }
.rows { width: 100%; border-collapse: collapse; font-size: 15px; margin-top: 4px; }
.rows td { padding: 5px 0; border-bottom: 1px solid var(--rule-3); vertical-align: middle; }
.rows td.n { text-transform: capitalize; width: 42%; }
.rows td.v { text-align: right; font-family: var(--mono); font-size: 13px; width: 70px; }
.rows .track { height: 7px; border: 1px solid var(--rule-2); margin: 0 14px; position: relative; }
.rows .track i { position: absolute; inset: 0 auto 0 0; background: var(--ink); transition: width .8s cubic-bezier(.6,.1,.3,1); }
.block { margin-top: 26px; }
.say { font-size: 15.5px; margin: 10px 0 0; color: var(--ink-2); }
.experts { width: 100%; border-collapse: collapse; font-size: 15px; }
.experts th { text-align: left; font-weight: 400; font-variant: small-caps; text-transform: lowercase; letter-spacing: .06em; color: var(--ink-3); border-bottom: 1px solid var(--rule); padding: 0 0 6px; font-size: 14px; }
.experts td { padding: 8px 0; border-bottom: 1px solid var(--rule-3); }
.experts td.g { text-transform: capitalize; }
.experts .unc { display: inline-block; width: 70px; height: 7px; border: 1px solid var(--rule-2); vertical-align: middle; position: relative; margin-right: 8px; }
.experts .unc i { position: absolute; inset: 0 auto 0 0; background: var(--ink-2); }
.stress { width: 100%; border-collapse: collapse; font-size: 15px; }
.stress th { text-align: left; font-weight: 400; font-variant: small-caps; text-transform: lowercase; letter-spacing: .06em; color: var(--ink-3); border-bottom: 1px solid var(--rule); padding: 0 8px 6px 0; font-size: 14px; }
.stress tr.r { cursor: pointer; }
.stress tr.r td { padding: 9px 8px 9px 0; border-bottom: 1px solid var(--rule-3); vertical-align: middle; }
.stress tr.r:hover td { background: var(--rule-3); }
.stress tr.r.on td { background: var(--ink); color: var(--paper); }
.stress tr.r.on .mini, .stress tr.r.on .mini i { border-color: var(--paper); }
.stress tr.r.on .p-img { background: var(--paper); }
.stress tr.r.on .p-txt { background: repeating-linear-gradient(-45deg, var(--paper) 0 1.3px, transparent 1.3px 4.6px); }
.stress tr.r.on .p-int { background: radial-gradient(circle, var(--paper) 1.15px, transparent 1.35px) 0 0 / 5px 5px; }
.stress td.c { width: 30%; }
.stress td.c small { display: block; font-size: 12.5px; opacity: .7; line-height: 1.3; }
.stress .mini { display: flex; height: 12px; border: 1px solid var(--ink); width: 130px; }
.stress .mini i { display: block; height: 100%; border-right: 1px solid var(--ink); }
.stress .mini i:last-child { border-right: 0; }
.stress td.pr { text-transform: capitalize; }
.stress td.d { font-family: var(--mono); font-size: 12.5px; white-space: nowrap; text-align: right; }

/* ── explore block / charts ───────────────────────────── */
.explore { display: grid; grid-template-columns: minmax(0, 1.15fr) minmax(260px, 0.85fr); gap: 40px; align-items: start; margin-top: 10px; border-top: 1px solid var(--rule); padding-top: 22px; }
.tri { position: relative; width: 100%; aspect-ratio: 1.08; }
.tri canvas { position: absolute; inset: 0; width: 100%; height: 100%; }
.chips { display: flex; flex-wrap: wrap; gap: 0; border: 1px solid var(--rule); width: max-content; max-width: 100%; }
.chips button { border: 0; border-right: 1px solid var(--rule); background: none; padding: 4px 11px; cursor: pointer; font-size: 14.5px; }
.chips button:last-child { border-right: 0; }
.chips button[aria-pressed="true"] { background: var(--ink); color: var(--paper); }
.chips button:disabled { color: var(--ink-3); cursor: not-allowed; }
.controls { display: flex; flex-wrap: wrap; gap: 14px; margin-bottom: 14px; }
.gmean { margin-top: 14px; }
.gmean .gl { display: flex; justify-content: space-between; font-size: 14.5px; margin-bottom: 4px; }
.tip { position: fixed; z-index: 90; pointer-events: none; background: var(--paper); border: 1px solid var(--ink); padding: 10px 12px; font-size: 13.5px; min-width: 220px; opacity: 0; transition: opacity .1s; }
.tip.on { opacity: 1; }
.tip .id { font-family: var(--mono); font-size: 11.5px; color: var(--ink-3); margin-bottom: 6px; word-break: break-all; }
.tip .row { display: flex; justify-content: space-between; gap: 16px; }
.tip .row span:last-child { font-family: var(--mono); font-size: 12px; }

.grid3 { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 40px; margin-top: 14px; }
.grid3 h4 { font-family: var(--display); font-weight: 400; font-size: 21px; margin: 0 0 6px; }

/* ── table ────────────────────────────────────────────── */
.table-wrap { overflow-x: auto; margin-top: 10px; }
table.res { width: 100%; border-collapse: collapse; font-size: 15px; min-width: 860px; }
table.res caption { caption-side: top; text-align: left; font-size: 14px; color: var(--ink-2); padding-bottom: 10px; }
table.res caption b { font-variant: small-caps; letter-spacing: .05em; font-weight: 400; color: var(--ink); }
table.res th, table.res td { padding: 5px 10px; text-align: right; white-space: nowrap; }
table.res th:first-child, table.res td:first-child { text-align: left; padding-left: 0; }
table.res thead th { font-weight: 400; border-top: 1.5px solid var(--ink); border-bottom: 1px solid var(--ink); padding-top: 8px; padding-bottom: 8px; }
table.res tbody tr:last-child td { border-bottom: 1.5px solid var(--ink); }
table.res td .num { font-size: 13.5px; }
table.res td small { font-family: var(--mono); font-size: 11px; color: var(--ink-3); margin-left: 3px; }
table.res tr.grp td { border-top: 1px solid var(--rule-2); }
table.res tr.ours td { font-style: italic; }
table.res tr.ours td:first-child::after { content: " ←"; font-style: normal; color: var(--ink-3); }
table.res td.best .num { font-weight: 700; }

/* ── colophon ─────────────────────────────────────────── */
.colophon { padding: 70px 0 90px; display: grid; grid-template-columns: var(--margin) minmax(0, var(--measure)); gap: 40px; }
.colophon h2 { font-family: var(--display); font-weight: 400; font-size: 28px; margin: 0; }
.colophon dl { display: grid; grid-template-columns: 120px 1fr; gap: 6px 18px; margin: 0; font-size: 16px; }
.colophon dt { color: var(--ink-3); font-variant: small-caps; text-transform: lowercase; letter-spacing: .06em; }
.colophon dd { margin: 0; }

/* ── responsive ───────────────────────────────────────── */
@media (max-width: 1180px) {
  :root { --margin: 170px; }
  .bar nav a:not(.on) span + * { display: none; }
}
@media (max-width: 980px) {
  .col { margin-left: 0; }
  .sn { position: static; display: block; width: auto; border-left: 1px solid var(--rule-2); padding-left: 12px; margin: 0 0 1em; }
  .abstract, .chapter-head, .colophon { grid-template-columns: 1fr; gap: 10px; }
  .chapter-head .lede { grid-column: 1; }
  .scrolly { grid-template-columns: 1fr; }
  .stage { top: 52px; height: auto; z-index: 2; background: var(--paper); padding: 8px 0; }
  .step { min-height: 38vh; }
  .instrument, .explore, .grid3 { grid-template-columns: 1fr; }
  .instrument .in { border-right: 0; border-bottom: 1px solid var(--rule); }
  .bar nav { display: none; }
  .authors { grid-template-columns: 1fr 1fr; }
  .authors .guide { justify-self: start; text-align: left; }
}
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { transition: none !important; animation: none !important; }
  html { scroll-behavior: auto; scroll-snap-type: none; }
}