/*
 * The manual, dressed as the app.
 *
 * Every colour here is copied from src/theme/variables.css rather than picked
 * again by eye. A handbook that is a shade off from the thing it documents
 * reads as a handbook for something else.
 */

:root {
  --bg: #061720;
  --surface: #0d2b38;
  --surface-raised: #123a48;
  --rail: #041219;
  --accent: #2bc6e8;
  --accent-dim: #1b7f96;
  --text: #e6f3f7;
  --muted: #a8c2cc;
  --caution: #e8b34a;
  --chip: #17323d;
  --chip-active: #0b4c5c;
  --border: #14313d;
  --radius: 10px;

  --font: system-ui, -apple-system, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: 24px;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font);
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

/* The two-column frame: the app's own rail, and everything else. */
.shell {
  display: flex;
  min-height: 100vh;
}

.rail {
  position: sticky;
  top: 0;
  align-self: flex-start;
  width: 264px;
  height: 100vh;
  flex-shrink: 0;
  overflow-y: auto;
  background: var(--rail);
  border-right: 1px solid var(--border);
  padding: 18px 10px 28px;
}

.rail-brand {
  display: flex;
  align-items: baseline;
  gap: 8px;
  padding: 0 10px 14px;
}

.rail-brand strong {
  font-size: 19px;
  letter-spacing: -0.01em;
}

.rail-brand span {
  color: var(--muted);
  font-size: 12px;
  font-variant-numeric: tabular-nums;
}

.rail h2 {
  margin: 18px 0 4px;
  padding: 0 10px;
  color: var(--muted);
  font-size: 10px;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.rail a {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  min-height: 34px;
  padding: 0 10px;
  border-radius: 8px;
  color: var(--text);
  font-size: 14px;
  text-decoration: none;
}

.rail a:hover {
  background: var(--chip);
}

.rail a.here {
  background: var(--chip-active);
  color: var(--accent);
  font-weight: 600;
}

.rail a small {
  color: var(--muted);
  font-size: 11px;
  font-variant-numeric: tabular-nums;
}

.page {
  flex: 1;
  min-width: 0;
  padding: 34px 40px 90px;
}

.page > * {
  max-width: 980px;
}

/* Type. */
h1 {
  margin: 0 0 6px;
  font-size: 34px;
  line-height: 1.15;
  letter-spacing: -0.02em;
}

.lede {
  margin: 0 0 30px;
  color: var(--muted);
  font-size: 17px;
  max-width: 70ch;
}

section {
  margin: 0 0 46px;
  scroll-margin-top: 20px;
}

h2 {
  margin: 0 0 4px;
  font-size: 24px;
  letter-spacing: -0.01em;
}

h3 {
  margin: 26px 0 6px;
  font-size: 17px;
}

p {
  margin: 0 0 14px;
  max-width: 72ch;
}

ul,
ol {
  margin: 0 0 14px;
  padding-left: 20px;
  max-width: 72ch;
}

li {
  margin: 0 0 6px;
}

a {
  color: var(--accent);
}

code,
kbd {
  background: var(--chip);
  border: 1px solid var(--border);
  border-radius: 5px;
  padding: 1px 6px;
  font-family: var(--font);
  font-size: 0.9em;
}

kbd {
  background: var(--surface-raised);
  font-weight: 600;
}

/* Figures: a screenshot with its caption, framed like a card in the app. */
figure {
  margin: 18px 0 22px;
  max-width: 100%;
}

figure img {
  display: block;
  width: 100%;
  height: auto;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--surface);
}

/*
 * A cutout is shown at its own size, or at most twice it.
 *
 * Stretching a 208-pixel strip of the rail across a 720-pixel column turns a
 * crisp screenshot into a blurred one, which is worse than a small picture.
 */
figure.cutout img {
  width: auto;
  max-width: 100%;
}

figure.cutout {
  max-width: 560px;
}

figure.tall {
  max-width: 240px;
}

figure.wide-strip {
  max-width: 100%;
}

figure.narrow {
  max-width: 720px;
}

figcaption {
  margin-top: 8px;
  color: var(--muted);
  font-size: 13px;
  line-height: 1.5;
}

/* A note that is worth stopping for. */
.note {
  border: 1px solid var(--border);
  border-left: 3px solid var(--accent-dim);
  background: var(--surface);
  border-radius: var(--radius);
  padding: 12px 16px;
  margin: 0 0 18px;
  max-width: 72ch;
}

.note.caution {
  border-left-color: var(--caution);
}

.note p:last-child {
  margin-bottom: 0;
}

.note strong {
  color: var(--accent);
}

.note.caution strong {
  color: var(--caution);
}

/* Tables, for the button maps and the figures. */
table {
  border-collapse: collapse;
  width: 100%;
  max-width: 72ch;
  margin: 0 0 18px;
  font-size: 15px;
}

th,
td {
  border-bottom: 1px solid var(--border);
  padding: 8px 10px;
  text-align: left;
  vertical-align: top;
}

th {
  color: var(--muted);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

td:first-child {
  white-space: nowrap;
  font-weight: 600;
}

/* Callouts drawn over a screenshot, numbered like a parts diagram. */
.diagram {
  position: relative;
  margin: 18px 0 10px;
}

.diagram img {
  display: block;
  width: 100%;
  border: 1px solid var(--border);
  border-radius: var(--radius);
}

.pin {
  position: absolute;
  width: 26px;
  height: 26px;
  margin: -13px 0 0 -13px;
  border-radius: 999px;
  background: var(--accent);
  color: #04222c;
  font-size: 14px;
  font-weight: 700;
  line-height: 26px;
  text-align: center;
  box-shadow: 0 0 0 3px rgba(6, 23, 32, 0.85);
}

.legend {
  margin: 0 0 22px;
  padding: 0;
  list-style: none;
  max-width: 72ch;
}

.legend li {
  display: flex;
  gap: 10px;
  align-items: baseline;
  margin-bottom: 8px;
}

.legend b {
  display: inline-block;
  width: 24px;
  height: 24px;
  flex-shrink: 0;
  border-radius: 999px;
  background: var(--accent);
  color: #04222c;
  font-size: 13px;
  line-height: 24px;
  text-align: center;
}

/* Cards for a row of short facts. */
.cards {
  display: grid;
  gap: 12px;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  margin: 0 0 22px;
  max-width: 980px;
}

.cards div {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 14px 16px;
}

.cards h4 {
  margin: 0 0 4px;
  font-size: 15px;
}

.cards p {
  margin: 0;
  color: var(--muted);
  font-size: 14px;
}

footer {
  border-top: 1px solid var(--border);
  padding-top: 18px;
  color: var(--muted);
  font-size: 13px;
  max-width: 72ch;
}

@media (max-width: 900px) {
  .shell {
    display: block;
  }

  .rail {
    position: static;
    width: auto;
    height: auto;
    border-right: 0;
    border-bottom: 1px solid var(--border);
  }

  .page {
    padding: 24px 18px 60px;
  }
}