/* Swap — paper and ink. Warm neutrals, one accent (persimmon) kept for the story: the patients
 * that only 3-way swaps help. Serif for display type, system sans for everything you read or click.
 * Light and dark via prefers-color-scheme; system fonts only. */

:root {
  color-scheme: light dark;

  --paper: #f5f1e8;
  --paper-2: #ece6d8;
  --surface: #fbf8f1;
  --ink: #1c1a16;
  --ink-2: #45403a;
  --muted: #655d50;
  --line: #d9d1c0;
  --line-strong: #b3a992;

  --accent: #c9461d;
  --accent-ink: #a3350f;
  --accent-soft: #f3ddd2;
  --on-accent: #ffffff;
  --green: #2c6a4b;
  --green-soft: #dfeadf;
  --ochre: #8a5b00;
  --ochre-soft: #f1e4bf;
  --bad: #9f1d1d;

  --c-pair: #2c2a25;
  --c-donor: #2c6a4b;
  --c-edge: #8c8372;
  --c-fail: #9f1d1d;

  --dot-kept: #26241f;
  --dot-gain: #c9461d;
  --dot-out: #a39a85;
  --dot-ring: #b7791f;

  --radius: 4px;
  --top-h: 60px;
  --serif: "Iowan Old Style", "Palatino Linotype", Palatino, "Book Antiqua", Georgia, "Noto Serif", "DejaVu Serif", serif;
  --sans: system-ui, -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --mono: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
}

@media (prefers-color-scheme: dark) {
  :root {
    --paper: #14120f;
    --paper-2: #1e1b16;
    --surface: #1a1713;
    --ink: #efe9db;
    --ink-2: #cfc7b6;
    --muted: #a69d8a;
    --line: #302b22;
    --line-strong: #4c4436;

    --accent: #ff7d57;
    --accent-ink: #ffa488;
    --accent-soft: #3a2018;
    --on-accent: #1a0e08;
    --green: #86cfa3;
    --green-soft: #17271e;
    --ochre: #e2b45c;
    --ochre-soft: #302612;
    --bad: #ff8d8d;

    --c-pair: #5c5548;
    --c-donor: #4c9a6c;
    --c-edge: #7a705e;
    --c-fail: #ff8d8d;

    --dot-kept: #e9e2d1;
    --dot-gain: #ff7d57;
    --dot-out: #6f6657;
    --dot-ring: #e2b45c;
  }
}

* { box-sizing: border-box; }
[hidden] { display: none !important; }

html { -webkit-text-size-adjust: 100%; scroll-padding-top: calc(var(--top-h) + 12px); }
body {
  margin: 0; background: var(--paper); color: var(--ink);
  font: 16px/1.6 var(--sans);
}
body.no-scroll { overflow: hidden; }
body.has-tour main { padding-bottom: 15rem; }

h1, h2, h3, h4 { margin: 0 0 0.45rem; font-weight: 600; line-height: 1.15; }
h1, h2, h3 { font-family: var(--serif); letter-spacing: -0.01em; }
h1 { font-size: clamp(2.7rem, 1.6rem + 5.4vw, 5rem); line-height: 1; letter-spacing: -0.025em; }
h2 { font-size: clamp(1.7rem, 1.2rem + 1.8vw, 2.3rem); }
h3 { font-size: 1.3rem; }
h4 { font-size: 0.95rem; margin-top: 1rem; }
p { margin: 0.45rem 0; }
ul, ol { margin: 0.4rem 0; padding-left: 1.2rem; }
a { color: var(--accent-ink); text-underline-offset: 3px; }
button { font: inherit; color: inherit; }

.muted { color: var(--muted); }
.small { font-size: 0.86rem; }
.mono { font-family: var(--mono); font-size: 0.85em; }
.kicker {
  font: 700 0.74rem/1.3 var(--sans); letter-spacing: 0.14em; text-transform: uppercase;
  color: var(--muted); margin: 0 0 0.8rem;
}
.sr-only {
  position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px;
  overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; border: 0;
}
.skip-link {
  position: absolute; left: 0.5rem; top: -3rem; z-index: 100;
  background: var(--paper); color: var(--ink); padding: 0.5rem 0.8rem; border: 1px solid var(--ink);
}
.skip-link:focus { top: 0.5rem; }
.svg-defs { position: absolute; }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; }
main:focus, main:focus-visible { outline: none; }

/* ------------------------------------------------------------------- top bar */

.topbar { position: sticky; top: 0; z-index: 40; background: var(--paper); border-bottom: 1px solid var(--line); }
.topbar-inner {
  max-width: 1040px; margin: 0 auto; padding: 0 1rem; height: var(--top-h);
  display: flex; align-items: center; gap: 1.6rem;
}
.brand {
  font: 700 1.7rem/1 var(--serif); letter-spacing: -0.03em; color: var(--ink); text-decoration: none;
}
.brand::after { content: "."; color: var(--accent); }
.stepper { flex: 1 1 auto; min-width: 0; }
.stepper ol { list-style: none; margin: 0; padding: 0; display: flex; gap: 1.5rem; }
.stepper a {
  display: flex; align-items: baseline; gap: 0.45rem; padding: 1.15rem 0 1rem; text-decoration: none;
  color: var(--muted); font-weight: 600; font-size: 0.94rem; border-bottom: 2px solid transparent;
  margin-bottom: -1px; white-space: nowrap;
}
.stepper a:hover { color: var(--ink); border-bottom-color: var(--line-strong); }
.stepper-num { font: 600 0.9rem var(--serif); font-variant-numeric: lining-nums; opacity: 0.8; }
.stepper a[aria-current="step"] { color: var(--ink); border-bottom-color: var(--accent); }
.stepper a[aria-current="step"] .stepper-num { color: var(--accent-ink); opacity: 1; }
.topbar-actions { display: flex; gap: 0.2rem; margin-left: auto; }

/* ---------------------------------------------------------------------- buttons */

.btn {
  display: inline-block; font-weight: 600; cursor: pointer; text-decoration: none; text-align: center;
  padding: 0.55rem 1.05rem; border-radius: var(--radius); line-height: 1.3;
  border: 1px solid var(--ink); background: transparent; color: var(--ink);
  transition: background 0.15s, color 0.15s, border-color 0.15s;
}
.btn:hover { background: var(--ink); color: var(--paper); }
.btn-primary { background: var(--accent); border-color: var(--accent); color: var(--on-accent); }
.btn-primary:hover { background: var(--accent-ink); border-color: var(--accent-ink); color: var(--on-accent); }
.btn-quiet { border-color: transparent; color: var(--ink-2); }
.btn-quiet:hover { background: transparent; color: var(--accent-ink); text-decoration: underline; text-underline-offset: 4px; }
.btn-sm { padding: 0.3rem 0.65rem; font-size: 0.86rem; }
.btn-lg { padding: 0.8rem 1.4rem; font-size: 1.05rem; }
.btn[disabled] { opacity: 0.4; cursor: default; pointer-events: none; }
.btn.is-busy { opacity: 1; cursor: progress; }
.btn.is-busy::before {
  content: ""; display: inline-block; width: 0.9em; height: 0.9em; margin-right: 0.55rem; vertical-align: -0.1em;
  border: 2px solid currentColor; border-right-color: transparent; border-radius: 50%; animation: spin 0.7s linear infinite;
}
.btn-row { display: flex; gap: 0.5rem; flex-wrap: wrap; }

/* ------------------------------------------------------------------------ layout */

main { max-width: 1040px; margin: 0 auto; padding: 0.4rem 1rem 2rem; }
.block { padding: 2.2rem 0 0.6rem; }
.block-sub { color: var(--ink-2); font-size: 1.05rem; max-width: 60ch; margin-bottom: 1.4rem; }
.fine-print { color: var(--muted); font-size: 0.84rem; }
.card-head { display: flex; align-items: center; justify-content: space-between; gap: 0.6rem; }

.banner {
  display: flex; align-items: center; justify-content: space-between; gap: 1rem;
  margin: 0.8rem 0; padding: 0.7rem 1rem; border-left: 4px solid var(--bad);
  background: var(--paper-2); font-weight: 600;
}
.banner p { margin: 0; }

/* ------------------------------------------------------------------------- hero */

.hero { position: relative; padding: 3rem 0 1.6rem; }
.hero > * { position: relative; z-index: 1; }
.hero::after {
  content: ""; position: absolute; z-index: 0; right: -1rem; top: 1.2rem; width: min(46%, 440px); height: 320px;
  background-image:
    radial-gradient(circle, var(--accent) 6px, transparent 6.6px),
    radial-gradient(circle, var(--dot-kept) 4.5px, transparent 5px);
  background-size: 84px 84px, 28px 28px;
  -webkit-mask-image: radial-gradient(ellipse at 72% 40%, #000 20%, transparent 72%);
  mask-image: radial-gradient(ellipse at 72% 40%, #000 20%, transparent 72%);
  opacity: 0.85; pointer-events: none;
}
.hero h1 { max-width: 16ch; }
.hero h1 em { color: var(--accent); font-style: italic; }
.hero-lead { font-size: clamp(1.1rem, 1rem + 0.5vw, 1.3rem); color: var(--ink-2); max-width: 52ch; margin: 1.4rem 0; }
.hero-lead strong { color: var(--ink); }
.hero-actions { display: flex; flex-wrap: wrap; gap: 0.7rem; margin: 1.6rem 0 1.4rem; }
.hero-live { max-width: 52ch; padding-top: 1rem; border-top: 1px solid var(--line); color: var(--ink-2); font-size: 1rem; }
.notice {
  display: inline-block; margin: 0 0 1.4rem; padding-left: 0.65rem; border-left: 3px solid var(--ochre);
  font: 700 0.74rem/1.4 var(--sans); letter-spacing: 0.1em; text-transform: uppercase; color: var(--ochre);
}

/* ------------------------------------------------------------ underlined words */

.term {
  font: inherit; color: inherit; background: none; border: none; padding: 0; cursor: help;
  border-bottom: 1.5px dotted var(--accent); text-decoration: none;
}
.term:hover { color: var(--accent-ink); }
.termtip {
  position: absolute; z-index: 80; background: var(--ink); color: var(--paper);
  border-radius: var(--radius); padding: 0.7rem 0.9rem 0.45rem; font-size: 0.9rem; line-height: 1.5;
}
.termtip p { margin: 0 0 0.2rem; }
.termtip .btn { color: var(--paper); padding: 0.15rem 0; }
.termtip .btn:hover { color: var(--paper); text-decoration: underline; }

/* ------------------------------------------------------------------- USP */

.usp { list-style: none; padding: 0; margin: 0; display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 1.8rem; counter-reset: usp; }
.usp li { counter-increment: usp; border-top: 2px solid var(--ink); padding-top: 0.9rem; }
.usp li::before { content: "0" counter(usp); display: block; font: 600 0.82rem var(--serif); color: var(--accent-ink); margin-bottom: 0.5rem; }
.usp h3 { font-size: 1.45rem; }
.usp p { color: var(--ink-2); font-size: 0.97rem; }
q { quotes: "“" "”"; font-style: italic; }
.why-graph { margin-top: 1.6rem; padding-left: 1rem; border-left: 3px solid var(--line-strong); max-width: 70ch; color: var(--ink-2); }

/* ------------------------------------------------------------------------ story */

.story {
  display: grid; grid-template-columns: minmax(0, 1.15fr) minmax(0, 1fr);
  grid-template-areas: "art text" "nav nav"; gap: 1rem 2.2rem; align-items: center;
}
.story-art { grid-area: art; background: var(--paper-2); border-radius: var(--radius); padding: 0.8rem; }
.story-text { grid-area: text; min-height: 10rem; }
.story-text h3 { font-size: 1.9rem; }
.story-text p { font-size: 1.08rem; color: var(--ink-2); }
.story-count { color: var(--muted) !important; font: 700 0.74rem var(--sans) !important; letter-spacing: 0.14em; text-transform: uppercase; }
.story-nav { grid-area: nav; display: flex; align-items: center; justify-content: space-between; gap: 1rem; border-top: 1px solid var(--line); padding-top: 1rem; }
.story-dots { display: flex; gap: 0.5rem; }
.story-dot { width: 9px; height: 9px; border-radius: 50%; border: 1.5px solid var(--ink); transition: background 0.2s; }
.story-dot.is-on { background: var(--ink); }

.art { display: block; width: 100%; height: auto; }
.art-box { fill: none; stroke: var(--line-strong); stroke-width: 2; stroke-dasharray: 6 5; }
.art-cap { fill: var(--muted); font: 600 11.5px var(--sans); }
.art-center { text-anchor: middle; }
.art-sm { font-size: 12px; }
.art-ink { fill: var(--ink); font-size: 14px; font-weight: 700; }
.art-patient, .art-pair { fill: var(--c-pair); }
.art-donor { fill: var(--accent); }
.art-out { fill: none; stroke: var(--dot-out); stroke-width: 2.5; }
.art-on { fill: #fff; font: 700 20px var(--serif); }
.art-arrow { fill: none; stroke: var(--c-edge); stroke-width: 3; }
.art-ok { stroke: var(--c-donor); }
.art-bad { stroke: var(--c-fail); stroke-dasharray: 7 6; }
.art-dash { stroke-dasharray: 6 5; }
.art-bad-text { fill: var(--c-fail); font: 700 22px var(--sans); }
.art-edges line { stroke: var(--line-strong); stroke-width: 1.6; }
.art-ring { fill: none; stroke: var(--accent); stroke-width: 4; stroke-linejoin: round; stroke-linecap: round; }
.svg-arrowhead { fill: var(--c-edge); }
.svg-arrowhead-bad { fill: var(--c-fail); }

/* -------------------------------------------------------------------- numbers */

.numbers { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); border-top: 2px solid var(--ink); }
.stat { padding: 1rem 1.4rem 0.6rem 0; }
.stat + .stat { padding-left: 1.4rem; border-left: 1px solid var(--line); }
.stat-label { margin: 0 0 0.1rem; font: 700 0.74rem var(--sans); letter-spacing: 0.12em; text-transform: uppercase; color: var(--muted); }
.stat-value { margin: 0; }
.stat-value > span {
  font: 600 clamp(3.4rem, 2rem + 6vw, 6rem)/1 var(--serif); letter-spacing: -0.03em; font-variant-numeric: lining-nums tabular-nums;
}
.stat-gain .stat-value > span { color: var(--accent); }
.sentence { font-size: 1.12rem; color: var(--ink-2); margin: 0.6rem 0 0; max-width: 64ch; }

/* ------------------------------------------------------------ mode bar + toggles */

.mode-bar { display: flex; align-items: center; justify-content: space-between; flex-wrap: wrap; gap: 0.8rem 1.4rem; margin: 2rem 0 1rem; }
.field-inline { display: flex; align-items: center; gap: 0.8rem; flex-wrap: wrap; }
.label { font: 700 0.74rem var(--sans); letter-spacing: 0.12em; text-transform: uppercase; color: var(--muted); }
.segmented { display: inline-flex; border: 1px solid var(--ink); border-radius: var(--radius); overflow: hidden; }
.seg { border: none; background: transparent; padding: 0.5rem 1rem; font-weight: 600; cursor: pointer; }
.seg + .seg { border-left: 1px solid var(--ink); }
.seg:hover { background: var(--paper-2); }
.seg.is-active { background: var(--ink); color: var(--paper); }
.check { display: inline-flex; align-items: center; gap: 0.5rem; font-weight: 600; cursor: pointer; font-size: 0.95rem; }
.check input, .switch input { width: 1.1rem; height: 1.1rem; accent-color: var(--accent); }

/* ---------------------------------------------------------------- explore layout */

.explore { display: grid; grid-template-columns: minmax(0, 1.5fr) minmax(300px, 1fr); gap: 2rem; align-items: start; }
.detail {
  position: sticky; top: calc(var(--top-h) + 14px); max-height: calc(100vh - var(--top-h) - 28px); overflow-y: auto;
  min-height: 14rem; padding: 1.2rem 1.3rem; background: var(--surface); border: 1px solid var(--line-strong); border-radius: var(--radius);
}
.detail-kicker { margin: 0 0 0.4rem; }
.detail h3 { font-size: 1.5rem; }
.detail h4 { margin-top: 1rem; font: 700 0.74rem var(--sans); letter-spacing: 0.12em; text-transform: uppercase; color: var(--muted); }

.map-wrap { position: relative; }
.map-overlay { position: absolute; z-index: 2; top: 1.4rem; left: 50%; transform: translateX(-50%); width: min(430px, 94%); box-shadow: 5px 5px 0 var(--line-strong); }
.map {
  display: grid; grid-template-columns: repeat(auto-fill, 22px); gap: 10px 9px; justify-content: space-between;
  padding: 0.3rem 0 1rem; min-height: 9rem; transition: opacity 0.2s;
}
.map:empty { background: linear-gradient(90deg, var(--paper-2), var(--paper), var(--paper-2)); background-size: 200% 100%; animation: shimmer 1.4s linear infinite; }
.map.is-loading { opacity: 0.4; pointer-events: none; }
@keyframes shimmer { to { background-position: -200% 0; } }

.dot {
  position: relative; width: 22px; height: 22px; padding: 0; border-radius: 50%; cursor: pointer;
  border: 2px solid var(--dot-out); background: transparent; display: inline-block; flex: none;
  transition: background-color 0.35s, border-color 0.35s, transform 0.12s, box-shadow 0.2s;
}
.dot:hover { transform: scale(1.2); }
.dot-kept { background: var(--dot-kept); border-color: var(--dot-kept); }
.dot-gain { background: var(--dot-gain); border-color: var(--dot-gain); }
.dot-maybe { border: 2px dashed var(--dot-gain); background: var(--accent-soft); }
.dot-out { border-color: var(--dot-out); background: transparent; }
.dot.is-committed::after {
  content: "✓"; position: absolute; inset: 0; display: grid; place-items: center;
  font: 700 12px/1 var(--sans); color: var(--paper); pointer-events: none;
}
.dot.is-hard { box-shadow: 0 0 0 2px var(--paper), 0 0 0 4px var(--dot-ring); }
.dot.is-mate { box-shadow: 0 0 0 2px var(--paper), 0 0 0 4px var(--ink); }
.dot.is-selected { transform: scale(1.3); z-index: 1; box-shadow: 0 0 0 2px var(--paper), 0 0 0 5px var(--ink); }
.dot:focus-visible { outline: 2px solid var(--accent); outline-offset: 4px; }
.dot-legend { width: 14px; height: 14px; pointer-events: none; border-width: 2px; }
.dot-legend.is-hard { box-shadow: 0 0 0 1.5px var(--paper), 0 0 0 3px var(--dot-ring); }

.legend { list-style: none; margin: 0; padding: 0.8rem 0 0; border-top: 1px solid var(--line); display: flex; flex-wrap: wrap; gap: 0.4rem 1.4rem; font-size: 0.86rem; color: var(--ink-2); }
.legend li { display: inline-flex; align-items: center; gap: 0.5rem; }
.legend-sm { border: none; padding: 0.3rem 0 0; font-size: 0.8rem; }
.key { display: inline-block; width: 11px; height: 11px; border-radius: 2px; flex: none; margin-right: 0.15rem; }
.key-type { background: var(--line-strong); }
.key-immune { background: var(--ochre); }
.key-can { background: var(--green); }
.key-busy { background: var(--c-edge); }
.key-me { background: var(--accent); border-radius: 50%; }

.status { color: var(--muted); font-size: 0.9rem; padding: 0.3rem 0; margin: 0; }
.status-bad { color: var(--bad); font-weight: 600; }
.status-muted { color: var(--muted); }

/* ---------------------------------------------------------------- loading states */

.spinner {
  display: inline-block; flex: none; width: 24px; height: 24px; border-radius: 50%;
  border: 3px solid var(--line-strong); border-top-color: var(--accent); animation: spin 0.8s linear infinite;
}
.spinner-sm { width: 14px; height: 14px; border-width: 2px; }
@keyframes spin { to { transform: rotate(360deg); } }
.loading {
  display: flex; gap: 0.9rem; align-items: flex-start; padding: 1rem 1.1rem;
  background: var(--surface); border: 1px solid var(--line-strong); border-left: 4px solid var(--accent); border-radius: var(--radius);
}
.loading-body { flex: 1; min-width: 0; }
.loading-text { margin: 0; font-weight: 650; }
.loading-sec { color: var(--muted); font-weight: 500; font-variant-numeric: tabular-nums; }
.loading-hint { margin: 0.2rem 0 0; color: var(--muted); font-size: 0.86rem; }
.loading-bar { display: block; position: relative; height: 3px; margin-top: 0.8rem; background: var(--paper-2); overflow: hidden; }
.loading-bar::after { content: ""; position: absolute; top: 0; bottom: 0; left: 0; width: 35%; background: var(--accent); animation: slide 1.2s ease-in-out infinite; }
@keyframes slide { from { transform: translateX(-100%); } to { transform: translateX(290%); } }
.status-loading { display: inline-flex; align-items: center; gap: 0.55rem; color: var(--ink-2); font-weight: 600; }

/* ------------------------------------------------------------------- folds */

.fold { border-top: 1px solid var(--line); }
.fold:last-child { border-bottom: 1px solid var(--line); }
.fold > summary {
  list-style: none; cursor: pointer; padding: 1rem 0; font: 600 1.15rem var(--serif);
  display: flex; align-items: baseline; justify-content: space-between; gap: 1rem;
}
.fold > summary::-webkit-details-marker { display: none; }
.fold > summary::after { content: "+"; font: 400 1.5rem/1 var(--sans); color: var(--accent-ink); flex: none; }
.fold[open] > summary::after { content: "−"; }
.fold > summary em { font: 400 0.85rem var(--sans); color: var(--muted); font-style: normal; margin: 0 auto 0 0.7rem; }
.fold > summary:hover { color: var(--accent-ink); }
.fold-body { padding: 0 0 1.4rem; }
.fold-inline > summary { cursor: pointer; font-weight: 600; font-size: 0.9rem; color: var(--accent-ink); margin: 0.8rem 0 0.3rem; }
#swap-count { margin: 0 auto 0 0.5rem; font: 400 0.9rem var(--sans); }
.mini-details > summary { cursor: pointer; font-weight: 600; color: var(--accent-ink); margin: 0.6rem 0; }
.setup { margin-top: 2.2rem; }
.setup-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 1rem 2rem; margin: 0.6rem 0 1rem; }
.field { display: flex; flex-direction: column; gap: 0.3rem; margin: 0.3rem 0; }
.field label { font-size: 0.88rem; font-weight: 650; color: var(--ink-2); display: flex; align-items: center; gap: 0.5rem; }
.field-row { display: flex; gap: 0.6rem; flex-wrap: wrap; align-items: stretch; margin: 0.5rem 0; }
.field-row > input { flex: 1 1 14rem; }
.seed-row { display: flex; gap: 0.5rem; }
input[type="range"] { width: 100%; accent-color: var(--accent); }
input[type="number"], input[type="text"], select {
  width: 100%; padding: 0.55rem 0.7rem; font: inherit; color: var(--ink); background: var(--surface);
  border: 1px solid var(--line-strong); border-radius: var(--radius);
}
.pill, .count { font-weight: 700; color: var(--accent-ink); }

.swap-list { list-style: none; padding: 0; margin: 0.4rem 0 0; max-height: 360px; overflow: auto; }
.swap-row {
  display: grid; grid-template-columns: 5rem 3.6rem 1fr; gap: 0.6rem; align-items: baseline; width: 100%;
  background: transparent; border: none; border-bottom: 1px solid var(--line); text-align: left;
  padding: 0.5rem 0.3rem; cursor: pointer; border-radius: 0;
}
.swap-row:hover { background: var(--paper-2); }
.swap-row.is-selected { background: var(--paper-2); box-shadow: inset 3px 0 0 var(--accent); }
.swap-n { font-weight: 650; }
.swap-len { color: var(--muted); font-size: 0.85rem; }
.swap-ids { font-family: var(--mono); font-size: 0.85rem; color: var(--ink-2); }

/* -------------------------------------------------------------- detail content */

.graph-host { height: 220px; background: var(--paper-2); border-radius: var(--radius); margin: 0.7rem 0; }
.graph-host-sm { height: 190px; }
.ring-steps { padding-left: 1.3rem; font-size: 0.95rem; }
.ring-steps li { padding: 0.12rem 0; }
.callout {
  border-left: 3px solid var(--ochre); background: var(--ochre-soft); color: var(--ink);
  padding: 0.6rem 0.85rem; margin: 0.9rem 0; font-size: 0.93rem;
}
.callout-good { border-left-color: var(--accent); background: var(--accent-soft); }
.callout .btn { margin-top: 0.5rem; }
.verdict { margin-top: 0.6rem; }
.reason-bar { display: flex; height: 10px; background: var(--paper-2); margin: 0.4rem 0 0.7rem; }
.reason-bar .seg-type { background: var(--line-strong); }
.reason-bar .seg-immune { background: var(--ochre); }
.reason-bar .seg-can { background: var(--green); }
.reason-list { list-style: none; padding: 0; margin: 0; font-size: 0.92rem; }
.reason-list li { padding: 0.15rem 0; }

.diff, .badge {
  display: inline-block; font: 700 0.68rem/1.4 var(--sans); letter-spacing: 0.08em; text-transform: uppercase;
  padding: 0.05rem 0.45rem; border: 1px solid currentColor; border-radius: 2px; white-space: nowrap;
}
.diff-easy, .badge-ok { color: var(--green); }
.diff-medium, .badge-warn { color: var(--ochre); }
.diff-hard, .badge-bad { color: var(--bad); }
.badge-info { color: var(--accent-ink); }
.badge-muted { color: var(--muted); }

/* -------------------------------------------------------------------- left out */

.facts { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); border-top: 2px solid var(--ink); margin: 0 0 2.2rem; }
.fact { padding: 0.9rem 1.4rem 0.4rem 0; }
.fact + .fact { padding-left: 1.4rem; border-left: 1px solid var(--line); }
.fact p { margin: 0; }
.fact-figure strong { font: 600 clamp(2rem, 1.4rem + 2vw, 2.8rem)/1.1 var(--serif); letter-spacing: -0.02em; }
.fact-label { font-weight: 650; margin-top: 0.15rem !important; }
.fact-note { color: var(--muted); font-size: 0.88rem; margin-top: 0.3rem !important; }
.list-wrap h3 { margin-bottom: 0.6rem; }
.rows { max-height: 480px; overflow: auto; border-top: 1px solid var(--line); }
.row-item {
  display: grid; grid-template-columns: 1fr auto; align-items: center; gap: 0.7rem; width: 100%;
  text-align: left; background: transparent; border: none; border-bottom: 1px solid var(--line);
  padding: 0.6rem 0.5rem; cursor: pointer;
}
.row-item:hover { background: var(--paper-2); }
.row-item.is-selected { background: var(--paper-2); box-shadow: inset 3px 0 0 var(--accent); }
.row-main { display: flex; flex-direction: column; }
.chips { display: flex; gap: 0.5rem; flex-wrap: wrap; }
.chip {
  font-size: 0.86rem; font-weight: 600; cursor: pointer; text-align: left; padding: 0.35rem 0.75rem;
  border: 1px solid var(--line-strong); border-radius: var(--radius); background: transparent; color: var(--ink-2);
}
.chip:hover { border-color: var(--ink); color: var(--ink); background: var(--paper-2); }

/* --------------------------------------------------------------------- what if */

.ask { display: grid; grid-template-columns: minmax(0, 5fr) minmax(0, 6fr); gap: 2rem; align-items: start; padding: 1.8rem 0; border-top: 1px solid var(--line); }
.ask:last-child { border-bottom: 1px solid var(--line); }
.ask h3 { font-size: 1.55rem; }
.ask .btn { margin-top: 0.5rem; }
.answer { font-size: 0.96rem; }
.answer:empty { display: none; }
.lead-line { font-weight: 600; }
.compare { display: flex; align-items: center; flex-wrap: wrap; gap: 0.6rem 1.1rem; margin: 0 0 0.8rem; }
.compare-cell { display: flex; flex-direction: column; align-items: flex-start; }
.compare-num { font: 600 3rem/1 var(--serif); font-variant-numeric: lining-nums tabular-nums; }
.compare-label { font: 700 0.68rem var(--sans); color: var(--muted); text-transform: uppercase; letter-spacing: 0.12em; }
.compare-arrow { color: var(--muted); font-size: 1.5rem; }
.compare-delta { display: flex; flex-direction: column; font: 600 1.4rem/1.1 var(--serif); }
.compare-delta .small { font: 400 0.82rem var(--sans); }
.compare-delta.up strong { color: var(--green); }
.compare-delta.down strong { color: var(--bad); }
.switch { display: flex; align-items: center; gap: 0.6rem; font-weight: 600; margin: 0.8rem 0 0; cursor: pointer; }
.fair-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 0.8rem; }
.fair-cell { border: 1px solid var(--line); border-radius: var(--radius); padding: 0.8rem 1rem; }
.fair-cell.is-active { border-color: var(--ink); background: var(--surface); }
.fair-title { margin: 0; font: 700 0.72rem var(--sans); color: var(--muted); text-transform: uppercase; letter-spacing: 0.12em; }
.fair-big { margin: 0.2rem 0; }
.fair-big strong { font: 600 2.4rem/1 var(--serif); }
.fairness-panel { margin-top: 0.4rem; }
table.mini { width: 100%; border-collapse: collapse; font-size: 0.86rem; }
table.mini th, table.mini td { text-align: left; padding: 0.3rem 0.45rem; border-bottom: 1px solid var(--line); }
table.mini th { color: var(--muted); font-weight: 700; font-size: 0.72rem; text-transform: uppercase; letter-spacing: 0.06em; }

/* ------------------------------------------------------------------------ plan */

.plan-actions { display: flex; align-items: center; flex-wrap: wrap; gap: 0.8rem 1.2rem; margin: 0 0 0.8rem; }
.plan-actions p { margin: 0; max-width: 46ch; }
.sheet {
  margin-top: 1.2rem; padding: 1.4rem 1.6rem; background: var(--surface);
  border: 1px solid var(--ink); border-radius: var(--radius); box-shadow: 6px 6px 0 var(--line-strong); max-width: 760px;
}
.sheet-head { display: flex; align-items: flex-start; justify-content: space-between; gap: 1rem; border-bottom: 2px solid var(--ink); padding-bottom: 0.7rem; }
.sheet-head h3 { font-size: 1.7rem; margin: 0; }
.sheet-facts { margin: 0.8rem 0; }
.sheet-facts p { margin: 0.2rem 0; }
.sheet-swaps { list-style: none; margin: 0.6rem 0 1rem; padding: 0; max-height: 320px; overflow: auto; border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.sheet-swaps > li { padding: 0.6rem 0.2rem; border-bottom: 1px solid var(--line); }
.sheet-swaps > li:last-child { border-bottom: none; }
.sheet-swap-title { margin: 0 0 0.15rem; }
.sheet-swaps ul { list-style: none; margin: 0; padding: 0; font-size: 0.92rem; color: var(--ink-2); }
.decision { margin: 1rem 0; padding: 0.9rem 1rem; border-left: 4px solid var(--ochre); background: var(--ochre-soft); }
.decision h4 { margin: 0 0 0.2rem; color: var(--ink); text-transform: none; letter-spacing: 0; font: 600 1.1rem var(--serif); }
.decision p { margin: 0.2rem 0; }
.decision-approved { border-left-color: var(--green); background: var(--green-soft); }
.decision-rejected { border-left-color: var(--bad); }
.decision-row { display: flex; flex-wrap: wrap; gap: 0.5rem; margin: 0.6rem 0 0.2rem; }
.decision-row input { flex: 1 1 14rem; width: auto; }
.ledger-wrap { margin-top: 2rem; max-width: 760px; }
.ledger { list-style: none; padding: 0; margin: 0; border-top: 1px solid var(--line); }
.ledger-row {
  display: flex; align-items: center; gap: 0.8rem; width: 100%; text-align: left; background: transparent;
  border: none; border-bottom: 1px solid var(--line); padding: 0.6rem 0.4rem; cursor: pointer;
}
.ledger-row:hover, .ledger-row.is-selected { background: var(--paper-2); }
.ledger-id { font-weight: 650; min-width: 4.5rem; }

/* ----------------------------------------------------------------------- proof */

.flow { display: flex; flex-wrap: wrap; align-items: center; gap: 0.5rem 0.8rem; margin: 0 0 1.8rem; font-size: 0.95rem; }
.flow span { padding: 0.25rem 0.7rem; border: 1px solid var(--line-strong); border-radius: var(--radius); }
.flow i { color: var(--muted); font-style: normal; }
.hood-list { display: block; }
.proof-summary { display: flex; align-items: center; gap: 0.8rem; padding: 0.75rem 1rem; font-weight: 650; margin: 0.6rem 0; border-left: 4px solid var(--green); background: var(--green-soft); }
.proof-summary.is-bad { border-left-color: var(--bad); background: var(--ochre-soft); }
.proof-summary .tick, .proof-summary .cross { font-size: 1.4rem; }
.table-wrap { overflow-x: auto; }
table.grid { width: 100%; border-collapse: collapse; font-size: 0.86rem; margin: 0.5rem 0; }
table.grid th, table.grid td { text-align: left; padding: 0.42rem 0.55rem; border-bottom: 1px solid var(--line); }
table.grid th { color: var(--muted); font-weight: 700; font-size: 0.72rem; text-transform: uppercase; letter-spacing: 0.06em; }
table.grid td.num { font-variant-numeric: tabular-nums; white-space: nowrap; }
table.grid td.args { max-width: 320px; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.tick { color: var(--green); font-weight: 800; }
.cross { color: var(--bad); font-weight: 800; }
.outcome-key { list-style: none; padding: 0; display: grid; gap: 0.4rem; }
.cypher { display: grid; gap: 0.4rem; }
.cypher-group h4 { color: var(--muted); }
.cypher-item { border: 1px solid var(--line); border-radius: var(--radius); background: var(--paper-2); margin: 0.3rem 0; }
.cypher-item > summary { cursor: pointer; padding: 0.4rem 0.7rem; font-family: var(--mono); font-size: 0.82rem; font-weight: 600; }
.cypher-item pre { margin: 0; padding: 0.7rem; overflow-x: auto; border-top: 1px solid var(--line); }
.cypher-item code { font-family: var(--mono); font-size: 0.8rem; white-space: pre; color: var(--ink-2); }

/* -------------------------------------------------------------------- pager */

.pager { display: flex; justify-content: space-between; gap: 1rem; margin: 2.4rem 0 0.5rem; padding-top: 1.4rem; border-top: 2px solid var(--ink); }
#pager-next { margin-left: auto; }

/* ------------------------------------------------------------------- glossary */

.backdrop { position: fixed; inset: 0; background: rgba(20, 16, 10, 0.5); z-index: 70; }
.drawer {
  position: fixed; top: 0; right: 0; bottom: 0; z-index: 75; width: min(440px, 94vw);
  background: var(--paper); border-left: 1px solid var(--ink); display: flex; flex-direction: column;
  animation: slide-in 0.2s ease;
}
@keyframes slide-in { from { transform: translateX(14px); opacity: 0.4; } to { transform: none; opacity: 1; } }
.drawer-head { display: flex; align-items: center; justify-content: space-between; padding: 0.9rem 1.2rem; border-bottom: 1px solid var(--line); }
.drawer-head h3 { margin: 0; }
.drawer-body { padding: 0.8rem 1.2rem 2rem; overflow-y: auto; }
.glossary dt { font: 600 1.1rem var(--serif); margin-top: 1.1rem; padding: 0.1rem 0; }
.glossary dt.is-focus { box-shadow: inset 3px 0 0 var(--accent); padding-left: 0.6rem; }
.glossary dd { margin: 0.1rem 0 0; color: var(--ink-2); font-size: 0.95rem; }

/* ----------------------------------------------------------------------- tour */

.tour {
  position: fixed; left: 50%; bottom: 14px; transform: translateX(-50%); z-index: 60;
  width: min(580px, calc(100% - 24px)); background: var(--paper);
  border: 1px solid var(--ink); border-radius: var(--radius); box-shadow: 5px 5px 0 var(--line-strong);
  padding: 0.9rem 1.15rem;
}
.tour-top { display: flex; align-items: center; gap: 0.7rem; }
.tour-top h3 { margin: 0; flex: 1 1 auto; font-size: 1.2rem; }
.tour-caption { font-size: 1rem; color: var(--ink-2); margin: 0.45rem 0 0.8rem; min-height: 3.2em; }
.tour-actions { display: flex; gap: 0.6rem; justify-content: flex-end; }
.tour-focus { animation: tour-pulse 1.6s ease 2; outline: 2px solid var(--accent); outline-offset: 6px; }
@keyframes tour-pulse { 0%, 100% { outline-color: var(--accent); } 50% { outline-color: transparent; } }

/* --------------------------------------------------------------------- footer */

.footer { border-top: 1px solid var(--line); margin-top: 2.5rem; background: var(--paper-2); }
.footer-inner { max-width: 1040px; margin: 0 auto; padding: 1.8rem 1rem 2.4rem; display: grid; grid-template-columns: 2fr 1fr; gap: 2rem; }
.footer h4 { font: 700 0.74rem var(--sans); letter-spacing: 0.14em; text-transform: uppercase; color: var(--muted); margin: 0 0 0.6rem; }
.limits { list-style: none; padding: 0; margin: 0; display: grid; gap: 0.5rem; color: var(--ink-2); font-size: 0.9rem; }
.footer-meta { color: var(--muted); font-size: 0.9rem; }

/* ----------------------------------------------------------------- responsive */

@media (max-width: 1100px) {
  .usp { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}
@media (max-width: 980px) {
  .explore { grid-template-columns: 1fr; gap: 1.4rem; }
  .detail { position: static; max-height: none; }
  .usp { grid-template-columns: 1fr; gap: 1.4rem; }
  .ask { grid-template-columns: 1fr; gap: 1rem; }
  .footer-inner { grid-template-columns: 1fr; }
  .hero::after { opacity: 0.35; width: 70%; right: -2rem; }
}
@media (max-width: 760px) {
  .usp { grid-template-columns: 1fr; gap: 1.4rem; }
  :root { --top-h: 98px; }
  body { font-size: 15.5px; }
  .topbar-inner { flex-wrap: wrap; height: auto; padding-top: 0.5rem; gap: 0 1rem; }
  .brand { order: 1; }
  .topbar-actions { order: 2; }
  .stepper { order: 3; flex: 1 0 100%; overflow-x: auto; scrollbar-width: none; }
  .stepper ol { gap: 1.1rem; }
  .stepper a { padding: 0.55rem 0 0.5rem; }
  .stepper a:not([aria-current="step"]) .stepper-label { display: none; }
  .stepper-num { font-size: 1.05rem; }
  .stepper a { align-items: center; }
  .hero { padding-top: 1.8rem; }
  .story { grid-template-columns: 1fr; grid-template-areas: "art" "text" "nav"; }
  .story-text { min-height: 0; }
  .numbers { grid-template-columns: 1fr; }
  .stat, .stat + .stat { display: flex; align-items: baseline; justify-content: space-between; gap: 1rem; padding: 0.7rem 0; border-left: none; border-bottom: 1px solid var(--line); }
  .stat-value > span { font-size: 3rem; }
  .facts { grid-template-columns: 1fr; }
  .fact, .fact + .fact { padding: 0.8rem 0; border-left: none; border-bottom: 1px solid var(--line); }
  .setup-grid, .fair-grid { grid-template-columns: 1fr; }
  .mode-bar { flex-direction: column; align-items: flex-start; }
  .segmented { width: 100%; }
  .seg { flex: 1 1 50%; padding: 0.55rem 0.4rem; font-size: 0.9rem; }
  .map { grid-template-columns: repeat(auto-fill, 24px); gap: 11px 8px; }
  .dot { width: 24px; height: 24px; }
  body.has-tour main { padding-bottom: 17rem; }
}
@media (max-width: 520px) {
  .hero::after { display: none; }
  .swap-row { grid-template-columns: 4.2rem 1fr; }
  .swap-len { display: none; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .loading-bar::after { animation: none; width: 100%; opacity: 0.35; }
  .spinner, .btn.is-busy::before { animation: none; }
  *, *::before, *::after { animation-duration: 0.001ms !important; animation-iteration-count: 1 !important; transition-duration: 0.001ms !important; }
}

/* ---- step 6: when a lab test fails, and "what FalkorDB did" ---------------------------- */
.arc-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); gap: 0.8rem; margin: 0.6rem 0 1rem; }
.arc-card { border: 1px solid var(--line); border-radius: var(--radius); background: var(--surface); padding: 0.7rem 0.8rem; }
.arc-title { margin: 0 0 0.5rem; }
.arc-buttons { display: flex; flex-wrap: wrap; gap: 0.4rem; }
.arc-buttons .btn { font-family: var(--mono); font-size: 0.8rem; }
.arc-buttons .btn:hover { border-color: var(--bad); color: var(--bad); }
#fail-impact, #fail-repair { margin-top: 1.6rem; }
#fail-impact .facts { grid-template-columns: repeat(4, minmax(0, 1fr)); }
.graph-work { margin: 0.6rem 0 0.2rem; }
.work-table { width: 100%; border-collapse: collapse; font-size: 0.85rem; margin-top: 0.4rem; }
.work-table th, .work-table td { text-align: left; padding: 0.3rem 0.4rem; border-bottom: 1px solid var(--line); vertical-align: top; }
.work-table .num { text-align: right; white-space: nowrap; font-variant-numeric: tabular-nums; }
.work-name { display: block; font-family: var(--mono); font-size: 0.72rem; color: var(--muted); }
.guard { padding: 0.5rem 0.7rem; border-left: 3px solid var(--green); background: var(--green-soft); font-size: 0.9rem; margin: 0.8rem 0; }
.guard-bad { border-left-color: var(--bad); background: var(--accent-soft); }
.blockers { list-style: none; padding: 0; margin: 0.4rem 0; display: grid; gap: 0.3rem; }
.blockers .chip { font-family: var(--mono); font-size: 0.8rem; cursor: default; }
@media (max-width: 640px) {
  #fail-impact .facts { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .work-table { font-size: 0.78rem; }
}
.blockers li { display: flex; align-items: center; gap: 0.5rem; font-size: 0.88rem; color: var(--ink-2); }
.blockers li .chip { flex: none; }