:root {
  color-scheme: light dark;

  --paper: #eef0f2;
  --paper-raised: #f8f9fa;
  --ink: #14181d;
  --ink-soft: #46505c;
  --ink-faint: #56606c;
  --rule: #cfd5db;
  --asphalt: #2a3038;
  --on-asphalt: #eceff2;
  --on-asphalt-soft: #b7c0ca;
  --sodium: #e0a021;
  --link: #1f5f8b;
  --step: #24658f;
  --meter-fill: #3a77a6;
  --meter-track: #dfe3e8;

  --measure: 68ch;
  --wide: 880px;
  --gutter: clamp(16px, 4vw, 48px);
  --section: clamp(48px, 8vw, 96px);
  --sans: "Overpass", "Segoe UI", system-ui, sans-serif;
  --mono: "Overpass Mono", ui-monospace, "Cascadia Mono", Consolas, monospace;
}

@media (prefers-color-scheme: dark) {
  :root {
    --paper: #1b2027;
    --paper-raised: #232a32;
    --ink: #e6e9ed;
    --ink-soft: #b3bcc6;
    --ink-faint: #a0abb7;
    --rule: #38414c;
    --asphalt: #0c0f13;
    --link: #8fc1e6;
    --step: #8fc1e6;
    --meter-fill: #6a9cc2;
    --meter-track: #2a313a;
  }
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 1.0625rem;
  line-height: 1.6;
}

a { color: var(--link); text-underline-offset: 0.18em; }
a:focus-visible, .map:focus-visible {
  outline: 3px solid var(--sodium);
  outline-offset: 3px;
}

.wrap { padding: 0 var(--gutter); max-width: 1180px; margin: 0 auto; }
.prose { max-width: var(--measure); }
.after-grid { margin-top: 1.4em; }

h1, h2, h3 { line-height: 1.12; margin: 0; letter-spacing: -0.01em; }
h1 { font-size: clamp(2rem, 4.6vw, 3rem); font-weight: 800; }
h2 { font-size: clamp(1.6rem, 3.4vw, 2.25rem); font-weight: 700; margin-bottom: 0.7em; }
h3 { font-size: 1.125rem; font-weight: 700; margin-bottom: 0.35em; }
p { margin: 0 0 1em; }

/* Masthead. The code map is the page's one loud element; the title stays modest beside it. */
.masthead {
  /* Dark in both themes, so the stage ramp is fixed here: lighter means further along. */
  --stage-identified: #4a7391;
  --stage-named: #6d9fc6;
  --stage-rewritten: #9cc9ea;
  --stage-verified: #f0f8ff;
  --hatch: repeating-linear-gradient(135deg, rgba(255, 255, 255, 0.2) 0 3px, rgba(255, 255, 255, 0.08) 3px 6px);
  background: var(--asphalt);
  color: var(--on-asphalt);
  padding: clamp(28px, 5vw, 56px) 0 clamp(28px, 5vw, 52px);
}
.masthead .lede {
  font-size: clamp(1.1rem, 2vw, 1.3rem);
  max-width: 52ch;
  margin: 0.55em 0 0.9em;
}
.status-line {
  max-width: 64ch;
  color: var(--on-asphalt-soft);
  margin: 0 0 28px;
}
.status-line strong { color: var(--sodium); font-weight: 700; }

/* Site navigation, shared by every page */
.nav { display: flex; flex-wrap: wrap; gap: 4px 22px; margin: 0 0 clamp(20px, 4vw, 36px); padding: 0; list-style: none; font-size: 0.9375rem; }
.nav a { color: var(--on-asphalt-soft); text-decoration: none; padding: 4px 0; border-bottom: 2px solid transparent; }
.nav a:hover { color: var(--on-asphalt); border-bottom-color: var(--on-asphalt-soft); }
.nav a[aria-current="page"] { color: var(--on-asphalt); font-weight: 700; border-bottom-color: var(--sodium); }
.masthead.compact { padding-bottom: clamp(22px, 4vw, 36px); }
.masthead.compact .lede { margin-bottom: 0; }
/* Links inside the dark masthead: the paper link colour is too dark on asphalt in the light theme. */
.masthead .lede a { color: var(--on-asphalt); }

/* In-page contents on a compact masthead (quality and tools pages). */
.page-toc { margin-top: 18px; }
.page-toc ul { display: flex; flex-wrap: wrap; gap: 8px 10px; list-style: none; margin: 0; padding: 0; font-size: 0.9375rem; }
.page-toc a {
  display: inline-block; padding: 4px 12px; border-radius: 999px; text-decoration: none;
  color: var(--on-asphalt); border: 1px solid rgba(255, 255, 255, 0.32);
}
.page-toc a:hover { border-color: var(--on-asphalt); }

/* Changelog and devlog entries */
.entries { max-width: var(--wide); }
.entry { padding: 26px 0; border-top: 1px solid var(--rule); }
.entry:last-child { border-bottom: 1px solid var(--rule); }
.entry-meta { display: flex; flex-wrap: wrap; gap: 4px 16px; align-items: baseline; color: var(--ink-faint); font-size: 0.9375rem; margin-bottom: 6px; }
.entry-meta time { font-family: var(--mono); font-size: 0.875rem; }
.entry-meta .commit { font-family: var(--mono); font-size: 0.875rem; }
.entry h2 { font-size: 1.375rem; margin-bottom: 0.5em; }
.entry h3 { margin-top: 1.3em; }
.entry ul, .entry ol { padding-left: 1.2em; margin: 0 0 1em; max-width: var(--measure); }
.entry li { margin-bottom: 0.4em; }
.entry p { max-width: var(--measure); }
/* Titles and lines can hold long native names with no break opportunity; let them wrap instead of widening the page. */
.entry h2, .entry p, .entry li { overflow-wrap: break-word; }
.entry table { margin: 0.4em 0 1.2em; font-size: 0.9875rem; max-width: 100%; }
/* Devlog tables carry sentences in the first column, so it must wrap. */
.entry td:first-child { white-space: normal; min-width: 9em; }
.entry td, .entry th { overflow-wrap: break-word; }
.entry td a { overflow-wrap: break-word; }
/* Long hashes and file names must be allowed to break, or they starve the other columns. */
.entry td code { overflow-wrap: anywhere; }
.evidence { font-size: 0.8125rem; font-weight: 700; padding: 1px 7px; border-radius: 3px; border: 1px solid var(--rule); color: var(--ink-soft); white-space: nowrap; }
.evidence.verified { border-color: var(--meter-fill); color: var(--step); }
code {
  font-family: var(--mono);
  font-size: 0.9em;
  background: color-mix(in srgb, var(--rule) 55%, transparent);
  padding: 1px 5px;
  border-radius: 3px;
  overflow-wrap: anywhere;
}
.entry a { overflow-wrap: anywhere; }
.toc { max-width: var(--measure); padding-left: 1.2em; margin: 0 0 var(--section); }
.toc li { margin-bottom: 0.3em; }
main.page { padding: var(--section) 0; }
main.page > .wrap > h2 { margin-bottom: 0.5em; }

.map-figure { margin: 0; }
.map-head {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: baseline;
  gap: 4px 24px;
  font-size: 0.9375rem;
  color: var(--on-asphalt-soft);
  margin-bottom: 12px;
}
.map-head #map-title { max-width: 74ch; }
.map-head strong { color: var(--on-asphalt); font-weight: 700; }
.map-head .addr { font-family: var(--mono); font-size: 0.875rem; color: var(--on-asphalt); min-height: 1.4em; }

/* Functions or bytes: shown only when the progress data carries byte totals per slice. */
.map-mode { display: flex; flex-wrap: wrap; align-items: center; gap: 6px; margin: 0 0 12px; font-size: 0.875rem; color: var(--on-asphalt-soft); }
.map-mode-label { margin-right: 4px; }
.map-mode button {
  font: inherit; color: var(--on-asphalt); background: none; cursor: pointer;
  border: 1px solid rgba(255, 255, 255, 0.38); border-radius: 4px; padding: 4px 12px; min-height: 32px;
}
.map-mode button[aria-pressed="true"] { background: var(--on-asphalt); border-color: var(--on-asphalt); color: var(--asphalt); font-weight: 700; }
.map-mode button:focus-visible { outline: 3px solid var(--sodium); outline-offset: 2px; }

.map-empty {
  border: 1px dashed rgba(255, 255, 255, 0.38);
  border-radius: 4px;
  min-height: clamp(120px, 16vw, 176px);
  display: flex;
  align-items: center;
  padding: 20px clamp(16px, 3vw, 32px);
  background: var(--hatch);
  background-size: auto;
}
.map-empty[hidden] { display: none; }
.map-empty p {
  margin: 0;
  max-width: 62ch;
  background: var(--asphalt);
  padding: 12px 16px;
  border-radius: 4px;
  color: var(--on-asphalt);
}

.map {
  display: grid;
  grid-template-columns: repeat(60, 1fr);
  gap: 2px;
  border-radius: 2px;
}
.map[hidden] { display: none; }
/* 60, 40 and 24 columns share a common multiple of 120, so a map of 120n slices fills whole rows at every width. */
@media (max-width: 900px) { .map { grid-template-columns: repeat(40, 1fr); } }
@media (max-width: 560px) { .map { grid-template-columns: repeat(24, 1fr); } }

.cell { aspect-ratio: 1; border-radius: 2px; background: var(--hatch); }
.cell[data-stage="identified"] { background: var(--stage-identified); }
.cell[data-stage="named"] { background: var(--stage-named); }
.cell[data-stage="rewritten"] { background: var(--stage-rewritten); }
.cell[data-stage="verified"] { background: var(--stage-verified); box-shadow: inset 0 0 0 2px rgba(18, 74, 115, 0.5); }
/* A square that is not yet mostly verified shows its verified share as a pale band rising from the bottom. */
.cell.part { background-image: linear-gradient(to top, var(--stage-verified) var(--done), transparent var(--done)); }
.cell:hover, .cell.active { outline: 2px solid var(--sodium); outline-offset: 0; }

.legend {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 22px;
  list-style: none;
  padding: 0;
  margin: 16px 0 0;
  font-size: 0.9375rem;
  color: var(--on-asphalt);
}
.legend[hidden] { display: none; }
.legend li { display: flex; align-items: center; gap: 8px; }
.legend .legend-note { color: var(--on-asphalt-soft); }
.swatch { width: 16px; height: 16px; border-radius: 2px; flex: none; }
.swatch.unmeasured { background: var(--hatch); }
.swatch.identified { background: var(--stage-identified); }
.swatch.named { background: var(--stage-named); }
.swatch.rewritten { background: var(--stage-rewritten); }
.swatch.verified { background: var(--stage-verified); box-shadow: inset 0 0 0 2px rgba(18, 74, 115, 0.5); }

.tip {
  position: fixed;
  z-index: 10;
  pointer-events: none;
  background: #0d1014;
  color: #e6e9ed;
  outline: 1px solid #38414c;
  font-size: 0.8125rem;
  line-height: 1.35;
  padding: 6px 9px;
  border-radius: 4px;
  max-width: 260px;
  opacity: 0;
}
.tip.on { opacity: 1; }
.tip .addr { font-family: var(--mono); }

/* Sections */
main section { padding-top: var(--section); }
main section.band {
  background: var(--paper-raised);
  border-bottom: 1px solid var(--rule);
  padding-bottom: var(--section);
}

/* Progress meters: one fill colour; the label names the stage. */
.meters { display: grid; gap: 18px; max-width: var(--wide); margin: 0; padding: 0; list-style: none; }
.meters[hidden], .meter-note[hidden] { display: none; }
.meter-row { display: grid; grid-template-columns: 11rem 1fr; gap: 6px 16px; align-items: center; }
.meter-label { font-weight: 700; }
.meter-value { color: var(--ink-soft); font-variant-numeric: tabular-nums; }
.meter-track {
  grid-column: 1 / -1;
  height: 12px;
  border-radius: 6px;
  background: var(--meter-track);
  box-shadow: inset 0 0 0 1px var(--rule);
  overflow: hidden;
}
.meter-fill { height: 100%; background: var(--meter-fill); border-radius: 0 6px 6px 0; }
.meter-note { color: var(--ink-soft); margin-top: 20px; max-width: var(--measure); }

/* Progress over time: three small line charts sharing a time axis, one per stage. */
.history { margin-top: 2.2em; max-width: var(--wide); }
.history[hidden] { display: none; }
.history-note { color: var(--ink-soft); max-width: var(--measure); font-size: 0.9375rem; }
.history-charts { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 18px 28px; }
.history-panel { margin: 0; min-width: 0; }
.history-panel figcaption { display: flex; flex-direction: column; margin-bottom: 4px; }
.history-label { font-weight: 700; }
.history-value { color: var(--ink-soft); font-size: 0.9375rem; font-variant-numeric: tabular-nums; min-height: 1.6em; }
.history-plot { border-radius: 4px; touch-action: pan-y; }
.history-plot:focus-visible { outline: 3px solid var(--sodium); outline-offset: 3px; }
.history-plot svg { display: block; overflow: visible; }
.history-plot .grid { stroke: var(--rule); stroke-width: 1; }
.history-plot .tick { fill: var(--ink-faint); font: 0.75rem var(--sans); font-variant-numeric: tabular-nums; }
.history-plot .line { fill: none; stroke: var(--meter-fill); stroke-width: 2; stroke-linejoin: round; stroke-linecap: round; }
.history-plot .dot { fill: var(--meter-fill); stroke: var(--paper-raised); stroke-width: 2; }
.history-plot .cross { stroke: var(--ink-faint); stroke-width: 1; }
.history-table { margin-top: 14px; }
.history-table summary { cursor: pointer; color: var(--link); width: fit-content; }
.history-table summary:focus-visible { outline: 3px solid var(--sodium); outline-offset: 3px; }
.history-table-scroll { max-height: 22rem; overflow-y: auto; margin-top: 8px; }
.history-table td { font-variant-numeric: tabular-nums; }
@media (max-width: 760px) { .history-charts { grid-template-columns: 1fr; } }

.measured { margin-top: 1.4em; max-width: var(--wide); }
.facts { list-style: none; margin: 0.4em 0 0; padding: 0; display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); gap: 0 32px; }
.facts li { padding: 9px 0; border-top: 1px solid var(--rule); color: var(--ink-soft); }
.facts strong { color: var(--ink); font-variant-numeric: tabular-nums; }

/* Steps: a real sequence, so it is numbered. */
.steps { list-style: none; counter-reset: step; padding: 0; margin: 0; max-width: var(--wide); }
.steps li {
  counter-increment: step;
  display: grid;
  grid-template-columns: 2.75rem 1fr;
  gap: 0 14px;
  padding: 16px 0;
  border-top: 1px solid var(--rule);
}
.steps li:last-child { border-bottom: 1px solid var(--rule); }
.steps li::before {
  content: counter(step);
  font-family: var(--mono);
  font-weight: 700;
  font-size: 1.25rem;
  color: var(--step);
  line-height: 1.3;
}
.steps p { margin: 0; color: var(--ink-soft); max-width: 64ch; }

/* The repository rule: two ruled lists with a divider between them. */
.rule-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  max-width: var(--wide);
  border-top: 3px solid var(--ink);
  border-bottom: 1px solid var(--rule);
}
.rule-grid > div { padding: 18px 28px 14px 0; }
.rule-grid > div + div { padding-left: 28px; border-left: 1px solid var(--rule); }
.rule-grid ul { margin: 0; padding-left: 1.1em; }
.rule-grid li { margin-bottom: 0.45em; }

/* Tables */
table { border-collapse: collapse; width: 100%; max-width: var(--wide); }
th, td { text-align: left; padding: 11px 16px 11px 0; border-bottom: 1px solid var(--rule); vertical-align: top; }
th { font-weight: 700; color: var(--ink-soft); font-size: 0.9375rem; }
td:first-child { font-weight: 700; white-space: nowrap; }
.phase-num { font-family: var(--mono); color: var(--ink-faint); display: inline-block; min-width: 1.5em; text-align: center; margin-right: 4px; }
.status { white-space: nowrap; color: var(--ink-faint); }
tr.current .phase-num { background: var(--sodium); color: #14181d; border-radius: 3px; font-weight: 700; }
tr.current .status, tr.done .status { color: var(--ink); font-weight: 700; }

/* What it makes possible */
.note { color: var(--ink-soft); max-width: var(--measure); }
.features { list-style: none; margin: 28px 0 0; padding: 0; display: grid; gap: clamp(28px, 5vw, 56px); max-width: 1040px; }
.feature { display: grid; grid-template-columns: minmax(0, 46fr) minmax(0, 54fr); gap: clamp(18px, 3vw, 40px); align-items: center; }
.feature figure { margin: 0; }
.feature img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  border-radius: 4px;
  background: var(--rule);
}
.feature figcaption, .closing-credit { font-size: 0.8125rem; color: var(--ink-faint); margin-top: 6px; }
.feature p { color: var(--ink-soft); margin: 0 0 0.6em; max-width: 52ch; }
.feature .when { color: var(--ink-faint); font-size: 0.9375rem; margin: 0; }
.plain-features { max-width: var(--measure); margin: clamp(28px, 5vw, 48px) 0 0; padding-left: 1.1em; }
.plain-features li { margin-bottom: 0.5em; }

.sources { padding-left: 1.1em; max-width: var(--measure); }
.sources li { margin-bottom: 0.6em; }

/* Closing pitch */
main section.closing {
  padding-top: 0;
  margin-top: var(--section);
  background: #0c0f13;
  color: var(--on-asphalt);
  position: relative;
  isolation: isolate;
}
.closing img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  z-index: -2;
}
.closing::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  background: linear-gradient(90deg, rgba(12, 15, 19, 0.92) 0%, rgba(12, 15, 19, 0.78) 48%, rgba(12, 15, 19, 0.35) 100%);
}
.closing .wrap { padding-top: clamp(56px, 10vw, 128px); padding-bottom: clamp(48px, 8vw, 104px); }
.closing h2 { font-size: clamp(1.9rem, 4.6vw, 3.25rem); font-weight: 800; max-width: 18ch; }
.closing p { max-width: 54ch; font-size: clamp(1.05rem, 1.6vw, 1.2rem); }
.closing .actions { display: flex; flex-wrap: wrap; gap: 12px 16px; margin: 1.6em 0 0; }
.closing .actions a {
  display: inline-block;
  padding: 11px 20px;
  border-radius: 4px;
  font-weight: 700;
  text-decoration: none;
  border: 2px solid var(--on-asphalt);
  color: var(--on-asphalt);
}
.closing .actions a.primary { background: var(--sodium); border-color: var(--sodium); color: #14181d; }
.closing .actions a:hover { text-decoration: underline; }
.closing .closing-credit { color: var(--on-asphalt-soft); margin-top: 2.4em; }

footer {
  background: var(--asphalt);
  color: var(--on-asphalt-soft);
  padding: 28px 0 36px;
  font-size: 0.9375rem;
}
footer p { max-width: var(--measure); margin: 0; }

/* Narrow screens: table rows become labelled blocks, features stack. */
@media (max-width: 720px) {
  table, thead, tbody, tr, td { display: block; width: 100%; }
  thead { position: absolute; width: 1px; height: 1px; overflow: hidden; clip-path: inset(50%); }
  tr { padding: 14px 0; border-bottom: 1px solid var(--rule); }
  td { border: 0; padding: 2px 0; }
  td:first-child { font-size: 1.125rem; white-space: normal; }
  td[data-label]::before { content: attr(data-label) ": "; color: var(--ink-faint); font-weight: 400; }
  tr.todo .status { display: none; }
  .rule-grid { grid-template-columns: 1fr; }
  .rule-grid > div + div { padding-left: 0; border-left: 0; border-top: 1px solid var(--rule); }
  .feature { grid-template-columns: 1fr; }
  .closing::before { background: rgba(12, 15, 19, 0.82); }
}

@media (max-width: 560px) {
  .meter-row { grid-template-columns: 1fr; }
  .steps li { grid-template-columns: 2rem 1fr; }
}

@media (prefers-reduced-motion: no-preference) {
  .tip { transition: opacity 0.12s; }
}