/* Shared stylesheet for the plain-language stage pages in docs/algorithm/.
 *
 * The LogoLabs system: warm charcoal ground, one copper accent, Playfair for display and
 * Inter for text. Every stage page links this file and writes content only, so fourteen
 * pages written separately still read as one document. Fonts come from Google with a real
 * fallback stack, because these pages are opened from disk and may well be offline.
 */

@import url("https://fonts.googleapis.com/css2?family=Playfair+Display:wght@500;600&family=Inter:wght@400;500;600&family=JetBrains+Mono:wght@400;500&display=swap");

:root {
  --ink: #23201d;
  --ink-soft: #55504a;
  --ink-faint: #8a837b;
  --paper: #faf8f5;
  --paper-raised: #ffffff;
  --rule: #e3ddd4;
  --copper: #c9754a;
  --copper-soft: #f2e2d8;
  --good: #4a7c59;
  --warn: #b4802a;

  --display: "Playfair Display", Georgia, "Times New Roman", serif;
  --text: Inter, -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --mono: "JetBrains Mono", "SF Mono", Consolas, "Liberation Mono", monospace;

  --measure: 34rem;
  --wide: 58rem;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --ink: #ece7e0;
    --ink-soft: #b3aca3;
    --ink-faint: #837c74;
    --paper: #1a1816;
    --paper-raised: #232019;
    --rule: #38332c;
    --copper: #e09263;
    --copper-soft: #3a2a1f;
    --good: #7fb08d;
    --warn: #d9a851;
  }
}

:root[data-theme="dark"] {
  --ink: #ece7e0;
  --ink-soft: #b3aca3;
  --ink-faint: #837c74;
  --paper: #1a1816;
  --paper-raised: #232019;
  --rule: #38332c;
  --copper: #e09263;
  --copper-soft: #3a2a1f;
  --good: #7fb08d;
  --warn: #d9a851;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font: 400 17px/1.65 var(--text);
  -webkit-font-smoothing: antialiased;
}

.wrap {
  max-width: var(--wide);
  margin: 0 auto;
  padding: 0 1.5rem 6rem;
}

/* ---------------------------------------------------------------- masthead */

header.masthead {
  border-bottom: 1px solid var(--rule);
  margin-bottom: 3rem;
  padding: 3.5rem 0 2.25rem;
}

.eyebrow {
  font: 500 0.72rem/1 var(--text);
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--copper);
  margin: 0 0 1rem;
}

header.masthead h1 {
  font: 600 clamp(2rem, 5vw, 3rem)/1.1 var(--display);
  margin: 0 0 0.75rem;
  text-wrap: balance;
  letter-spacing: -0.01em;
}

.standfirst {
  font-size: 1.15rem;
  color: var(--ink-soft);
  max-width: var(--measure);
  margin: 0;
}

/* ---------------------------------------------------------------- structure */

main { display: flex; flex-direction: column; gap: 2.75rem; }

section { display: flex; flex-direction: column; gap: 1rem; }

h2 {
  font: 600 1.6rem/1.2 var(--display);
  margin: 1.5rem 0 0;
  text-wrap: balance;
}

h3 {
  font: 600 1.02rem/1.3 var(--text);
  margin: 0.75rem 0 0;
  color: var(--ink);
}

p, li { max-width: var(--measure); margin: 0; }
ul, ol { margin: 0; padding-left: 1.25rem; display: flex; flex-direction: column; gap: 0.5rem; }

a { color: var(--copper); text-underline-offset: 2px; }

strong { font-weight: 600; }

code {
  font: 400 0.87em/1 var(--mono);
  background: var(--copper-soft);
  padding: 0.15em 0.35em;
  border-radius: 3px;
}

/* ---------------------------------------------------------------- figures */

figure {
  margin: 0.5rem 0;
  padding: 1.5rem;
  background: var(--paper-raised);
  border: 1px solid var(--rule);
  border-radius: 6px;
  display: flex;
  flex-direction: column;
  gap: 1rem;
  overflow-x: auto;
}

figure svg { max-width: 100%; height: auto; display: block; }

figcaption {
  font-size: 0.9rem;
  color: var(--ink-soft);
  max-width: var(--measure);
}

figcaption b { color: var(--ink); font-weight: 600; }

/* Labels drawn inside SVG figures. */
.fig-label { font: 500 11px var(--text); fill: var(--ink-soft); }
.fig-label-strong { font: 600 12px var(--text); fill: var(--ink); }
.fig-rule { stroke: var(--rule); }
.fig-ink { fill: var(--ink); }
.fig-accent { fill: var(--copper); }
.fig-accent-stroke { stroke: var(--copper); fill: none; }

/* ---------------------------------------------------------------- callouts */

.aside {
  border-left: 3px solid var(--copper);
  padding: 0.15rem 0 0.15rem 1.15rem;
  color: var(--ink-soft);
  max-width: var(--measure);
  font-size: 0.96rem;
}

.aside b, .aside strong { color: var(--ink); }

.plain {
  background: var(--copper-soft);
  border-radius: 6px;
  padding: 1.15rem 1.35rem;
  max-width: var(--measure);
}

.plain h3 { margin-top: 0; color: var(--copper); font-size: 0.75rem;
             letter-spacing: 0.12em; text-transform: uppercase; }

/* ---------------------------------------------------------------- tables */

.table-scroll { overflow-x: auto; }

table {
  border-collapse: collapse;
  font-size: 0.92rem;
  width: 100%;
  min-width: 30rem;
}

th, td {
  text-align: left;
  padding: 0.55rem 0.9rem 0.55rem 0;
  border-bottom: 1px solid var(--rule);
  vertical-align: top;
}

th {
  font: 600 0.72rem/1.4 var(--text);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--ink-faint);
}

td.num { font-variant-numeric: tabular-nums; white-space: nowrap; }

/* ---------------------------------------------------------------- nav */

nav.stages {
  border-top: 1px solid var(--rule);
  margin-top: 4rem;
  padding-top: 1.5rem;
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 1.5rem;
  font-size: 0.9rem;
}

nav.stages a { color: var(--ink-soft); text-decoration: none; }
nav.stages a:hover { color: var(--copper); text-decoration: underline; }
nav.stages a[aria-current="page"] { color: var(--copper); font-weight: 600; }

.pairlink {
  font-size: 0.88rem;
  color: var(--ink-faint);
  margin-top: 0.5rem;
}

:focus-visible { outline: 2px solid var(--copper); outline-offset: 2px; }

@media (prefers-reduced-motion: reduce) {
  * { animation: none !important; transition: none !important; }
}