/* Proven Commons site styles. No build step: this file is served as is. */

@font-face {
  font-family: "Inter";
  font-style: normal;
  font-weight: 100 900;
  font-display: swap;
  src: url("../fonts/inter-latin-wght.woff2") format("woff2");
}

@font-face {
  font-family: "Source Serif 4";
  font-style: normal;
  font-weight: 200 900;
  font-display: swap;
  src: url("../fonts/source-serif-4-latin-wght.woff2") format("woff2");
}

@font-face {
  font-family: "JetBrains Mono";
  font-style: normal;
  font-weight: 100 800;
  font-display: swap;
  src: url("../fonts/jetbrains-mono-latin-wght.woff2") format("woff2");
}

/* ---------- Tokens ---------- */

:root {
  --font-sans: "Inter", ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-serif: "Source Serif 4", ui-serif, Georgia, Cambria, "Times New Roman", serif;
  --font-mono: "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, "Liberation Mono", monospace;

  --bg: #f7f5f0;
  --surface: #ffffff;
  --surface-2: #efece4;
  --ink: #15181e;
  --ink-2: #3a404c;
  --muted: #5a6170;
  --line: #ddd8cd;
  --line-strong: #c9c2b4;

  --accent: #0a6847;
  --accent-strong: #07553a;
  --accent-soft: #e2f0e8;
  --on-accent: #ffffff;

  --band-bg: #15181e;
  --band-ink: #ece9e2;
  --band-muted: #c3c7cf;
  --band-accent: #6ad8a8;
  --band-line: #4a515c;

  --code-bg: #ece8df;

  --radius: 14px;
  --radius-sm: 8px;
  --shadow: 0 1px 2px rgb(20 24 30 / 0.05), 0 8px 24px -12px rgb(20 24 30 / 0.12);
  --wrap: 72rem;
  --gutter: clamp(1rem, 0.5rem + 2.5vw, 2.5rem);
  --header-h: 4rem;

  --arrow: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16'%3E%3Cpath d='M2.5 8h10M8.5 4l4 4-4 4' fill='none' stroke='black' stroke-width='1.6' stroke-linecap='round' stroke-linejoin='round'/%3E%3C/svg%3E");
  --check: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24'%3E%3Cpath d='M6.5 12.5l3.5 3.5 7.5-8' fill='none' stroke='black' stroke-width='2.6' stroke-linecap='round' stroke-linejoin='round'/%3E%3C/svg%3E");
}

@media screen and (prefers-color-scheme: dark) {
  :root {
    --bg: #0f1114;
    --surface: #161a1f;
    --surface-2: #13171b;
    --ink: #ece9e2;
    --ink-2: #c6cad2;
    --muted: #9ea5b1;
    --line: #272d35;
    --line-strong: #363e48;

    --accent: #62d3a0;
    --accent-strong: #86e0b7;
    --accent-soft: #11271e;
    --on-accent: #0b1a13;

    --band-bg: #161a1f;
    --band-line: #3a424d;

    --code-bg: #1d2229;

    --shadow: 0 1px 2px rgb(0 0 0 / 0.3), 0 8px 24px -12px rgb(0 0 0 / 0.5);
  }
}

/* ---------- Base ---------- */

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
  scroll-padding-top: calc(var(--header-h) + 1rem);
}

@media (prefers-reduced-motion: no-preference) {
  html {
    scroll-behavior: smooth;
  }
}

/* The footer sits at the bottom of short pages, such as the 404 page. */
body {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  min-height: 100dvh;
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--font-sans);
  font-size: 1.0625rem;
  line-height: 1.65;
  font-feature-settings: "cv11", "ss01";
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

main {
  flex: 1 0 auto;
}

h1,
h2,
h3,
h4 {
  font-family: var(--font-serif);
  font-weight: 600;
  line-height: 1.2;
  letter-spacing: -0.01em;
  margin: 0 0 0.5em;
  text-wrap: balance;
}

h1 {
  font-size: clamp(2.1rem, 1.35rem + 3.3vw, 3.6rem);
  line-height: 1.1;
  letter-spacing: -0.02em;
}

h2 {
  font-size: clamp(1.75rem, 1.35rem + 1.6vw, 2.5rem);
}

h3 {
  font-size: 1.3rem;
}

h4 {
  font-size: 1.2rem;
}

p {
  margin: 0 0 1em;
}

a {
  color: var(--accent);
  text-decoration-thickness: 1px;
  text-underline-offset: 0.18em;
}

a:hover {
  color: var(--accent-strong);
  text-decoration-thickness: 2px;
}

:focus-visible {
  outline: 3px solid var(--accent);
  outline-offset: 2px;
  border-radius: 4px;
}

main:focus {
  outline: none;
}

code,
pre {
  font-family: var(--font-mono);
  font-size: 0.875em;
  /* Show code exactly as written: no ligatures. */
  font-variant-ligatures: none;
  font-feature-settings: "liga" 0, "calt" 0;
}

:not(pre) > code {
  background: var(--code-bg);
  border-radius: 5px;
  padding: 0.1em 0.35em;
  /* Wrap at spaces first; split a long name only if it cannot fit. */
  overflow-wrap: break-word;
}

pre {
  margin: 0;
  overflow-x: auto;
}

pre code {
  font-size: inherit;
}

img,
svg {
  max-width: 100%;
}

.wrap {
  width: 100%;
  max-width: var(--wrap);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.eyebrow {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--accent);
  margin: 0 0 0.9rem;
}

.skip-link {
  position: absolute;
  left: 1rem;
  top: -10rem;
  z-index: 100;
  padding: 0.6rem 1rem;
  background: var(--ink);
  color: var(--bg);
  border-radius: var(--radius-sm);
  font-weight: 600;
}

.skip-link:focus {
  top: 1rem;
  color: var(--bg);
}

/* Shown when the home page cannot find a section in its source. */
.missing {
  padding: 1rem 1.15rem;
  border: 1px dashed var(--line-strong);
  border-radius: var(--radius-sm);
  color: var(--ink-2);
}

/* ---------- Mark ---------- */

.mark {
  flex: none;
  display: block;
}

.mark-bg {
  fill: var(--ink);
}

.mark-glyph {
  fill: none;
  stroke: var(--bg);
  stroke-width: 3.4;
  stroke-linecap: round;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  font-family: var(--font-serif);
  font-size: 1.2rem;
  font-weight: 650;
  letter-spacing: -0.01em;
  color: var(--ink);
  text-decoration: none;
  margin: 0;
}

a.brand:hover {
  color: var(--ink);
}

/* ---------- Header ---------- */

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  -webkit-backdrop-filter: saturate(1.4) blur(12px);
  backdrop-filter: saturate(1.4) blur(12px);
  border-bottom: 1px solid var(--line);
}

@supports not (background: color-mix(in srgb, red 50%, blue)) {
  .site-header {
    background: var(--bg);
  }
}

.site-header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem 1.5rem;
  min-height: var(--header-h);
  flex-wrap: wrap;
}

.site-nav ul {
  display: flex;
  gap: 0.25rem;
  list-style: none;
  margin: 0;
  padding: 0;
}

.site-nav a {
  display: block;
  padding: 0.4rem 0.7rem;
  border-radius: var(--radius-sm);
  color: var(--ink-2);
  font-size: 0.95rem;
  font-weight: 500;
  text-decoration: none;
  white-space: nowrap;
}

.site-nav a:hover {
  background: var(--surface-2);
  color: var(--ink);
}

.site-nav a[aria-current="page"] {
  color: var(--ink);
  background: var(--surface-2);
}

@media (max-width: 47.99rem) {
  :root {
    --header-h: 6.25rem;
  }

  .site-header {
    position: static;
  }

  html {
    scroll-padding-top: 1rem;
  }

  .site-header-inner {
    padding-block: 0.75rem 0.4rem;
  }

  .site-nav {
    width: 100%;
  }

  .site-nav ul {
    flex-wrap: wrap;
    gap: 0 0.1rem;
    margin-inline: -0.6rem;
  }

  .site-nav a {
    font-size: 0.92rem;
    padding: 0.5rem 0.6rem;
  }
}

/* The footer links to GitHub too, so the header drops it when space is short. */
@media (max-width: 29.99rem) {
  .site-nav .nav-wide {
    display: none;
  }
}

@media (max-width: 22.5rem) {
  .site-nav a {
    font-size: 0.88rem;
    padding-inline: 0.45rem;
  }
}

/* ---------- Buttons and arrow links ---------- */

.actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin: 0;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 2.9rem;
  padding: 0.65rem 1.2rem;
  border: 1px solid var(--line-strong);
  border-radius: 999px;
  background: var(--surface);
  color: var(--ink);
  font-weight: 600;
  font-size: 0.98rem;
  line-height: 1.2;
  text-decoration: none;
  transition: background-color 0.15s ease, border-color 0.15s ease, color 0.15s ease;
}

.button:hover {
  color: var(--ink);
  border-color: var(--ink-2);
  text-decoration: none;
}

.button-primary {
  background: var(--accent);
  border-color: var(--accent);
  color: var(--on-accent);
}

.button-primary:hover {
  background: var(--accent-strong);
  border-color: var(--accent-strong);
  color: var(--on-accent);
}

@media (prefers-reduced-motion: reduce) {
  .button {
    transition: none;
  }
}

/* The arrow is drawn, not typed, so screen readers do not read it out. */
.more a::after,
.link-row a::after {
  content: "";
  display: inline-block;
  width: 0.85em;
  height: 0.85em;
  margin-left: 0.3em;
  vertical-align: -0.08em;
  background-color: currentColor;
  -webkit-mask: var(--arrow) center / contain no-repeat;
  mask: var(--arrow) center / contain no-repeat;
}

/* ---------- Sections ---------- */

.section {
  padding-block: clamp(3.5rem, 2.5rem + 4vw, 6.5rem);
}

.section-alt {
  background: var(--surface-2);
  border-block: 1px solid var(--line);
}

.section-head {
  max-width: 44rem;
  margin-bottom: clamp(2rem, 1.5rem + 2vw, 3rem);
}

.section-head > p:not(.eyebrow):not(.aside-note):not(.more) {
  color: var(--ink-2);
  font-size: 1.1rem;
}

.section-head > :last-child {
  margin-bottom: 0;
}

.subhead {
  font-size: 1.45rem;
  margin: clamp(3rem, 2rem + 3vw, 4.5rem) 0 0.5rem;
}

.subhead-text {
  color: var(--ink-2);
  max-width: 44rem;
  margin-bottom: 1.5rem;
}

.note {
  color: var(--ink-2);
  max-width: 44rem;
  margin-top: 1.75rem;
}

.more {
  margin: 1.75rem 0 0;
  font-weight: 600;
}

.link-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 1.75rem;
  list-style: none;
  margin: 1.75rem 0 0;
  padding: 0;
  font-weight: 600;
}

/* ---------- Hero ---------- */

.hero {
  position: relative;
  overflow: hidden;
  padding-block: clamp(3.5rem, 2rem + 6vw, 7.5rem) clamp(3rem, 2rem + 4vw, 5.5rem);
}

/* A faint grid, as on squared paper, fading out to the left. */
.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(var(--line) 1px, transparent 1px),
    linear-gradient(90deg, var(--line) 1px, transparent 1px);
  background-size: 48px 48px;
  opacity: 0.55;
  -webkit-mask-image: linear-gradient(100deg, transparent 30%, black 95%);
  mask-image: linear-gradient(100deg, transparent 30%, black 95%);
  pointer-events: none;
}

.hero .wrap {
  position: relative;
}

.hero h1 {
  max-width: 20em;
  margin-bottom: 1.5rem;
}

.lede {
  max-width: 40rem;
  font-size: clamp(1.1rem, 1rem + 0.4vw, 1.25rem);
  color: var(--ink-2);
  margin-bottom: 2rem;
}

/* ---------- What a project ships ---------- */

.ships {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1rem;
  counter-reset: ships;
}

@media (min-width: 36rem) {
  .ships {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 64rem) {
  .ships {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

.ships li {
  counter-increment: ships;
  padding: 1.5rem;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.ships li::before {
  content: counter(ships, decimal-leading-zero);
  display: block;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--muted);
  margin-bottom: 1.25rem;
}

.ships h3 {
  margin-bottom: 0.4rem;
}

.ships p {
  margin: 0;
  color: var(--ink-2);
  font-size: 1rem;
}

/* ---------- Verified bar ---------- */

.bar-layout {
  display: grid;
  gap: 2rem 4rem;
}

@media (min-width: 60rem) {
  .bar-layout {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    align-items: start;
  }

  .bar-layout .section-head {
    margin-bottom: 0;
    position: sticky;
    top: calc(var(--header-h) + 2rem);
  }
}

.bar-body > .aside-note {
  margin-top: 1.5rem;
}

/* Paragraphs the brief puts after a quoted list. */
.after-list {
  max-width: 44rem;
  margin-top: 1.5rem;
  color: var(--ink-2);
}

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

.aside-note {
  padding: 1rem 1.15rem;
  border-left: 3px solid var(--accent);
  background: var(--surface);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  color: var(--ink-2);
  font-size: 1rem;
}

.checklist {
  list-style: none;
  margin: 0;
  padding: 0;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  counter-reset: bar;
}

.checklist li {
  counter-increment: bar;
  position: relative;
  padding: 1.15rem 1.35rem 1.15rem 3.6rem;
  border-top: 1px solid var(--line);
}

.checklist li:first-child {
  border-top: 0;
}

/* A bulleted bar gets check marks. A numbered one keeps its numbers,
   because the documents refer to items by number. */
.checklist li::before {
  content: "";
  position: absolute;
  left: 1.3rem;
  top: 1.3rem;
  width: 1.4rem;
  height: 1.4rem;
  border-radius: 50%;
  background: var(--accent-soft);
}

ul.checklist li::after {
  content: "";
  position: absolute;
  left: 1.5rem;
  top: 1.5rem;
  width: 1rem;
  height: 1rem;
  background-color: var(--accent);
  -webkit-mask: var(--check) center / contain no-repeat;
  mask: var(--check) center / contain no-repeat;
}

ol.checklist li::before {
  content: counter(bar);
  display: grid;
  place-items: center;
  color: var(--accent);
  font-family: var(--font-mono);
  font-size: 0.8rem;
  font-weight: 700;
  line-height: 1;
}

/* ---------- Projects ---------- */

.status {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  margin: 0 0 1rem;
  padding: 0.2rem 0.65rem;
  border: 1px solid var(--line-strong);
  border-radius: 999px;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--muted);
}

.status::before {
  content: "";
  width: 0.5rem;
  height: 0.5rem;
  border-radius: 50%;
  border: 1.5px solid currentColor;
}

.pilot {
  max-width: 52rem;
  padding: clamp(1.5rem, 1rem + 2vw, 2.5rem);
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: calc(var(--radius) + 4px);
  box-shadow: var(--shadow);
}

.pilot h3 {
  font-size: 1.6rem;
  margin-bottom: 0.6rem;
}

.pilot > p:last-child {
  margin: 0;
  color: var(--ink-2);
  font-size: 1.05rem;
}

.cards {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(100%, 18rem), 1fr));
  gap: 1rem;
}

.card {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  padding: 1.5rem;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.card h4 {
  font-size: 1.3rem;
  margin-bottom: 0.75rem;
}

.card p {
  margin: 0;
  color: var(--ink-2);
  font-size: 0.98rem;
}

.card-label {
  font-family: var(--font-mono);
  font-size: 0.75rem !important;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--muted) !important;
  margin-bottom: 0.35rem !important;
}

/* ---------- Factory steps ---------- */

.steps {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(100%, 16rem), 1fr));
  gap: 1rem;
  counter-reset: step;
}

.steps li {
  counter-increment: step;
  padding: 1.4rem 1.4rem 1.5rem;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.steps li::before {
  content: counter(step);
  display: grid;
  place-items: center;
  width: 2rem;
  height: 2rem;
  margin-bottom: 1rem;
  border-radius: 50%;
  background: var(--ink);
  color: var(--bg);
  font-family: var(--font-mono);
  font-size: 0.9rem;
  font-weight: 700;
}

.steps h3 {
  font-size: 1.2rem;
  margin-bottom: 0.4rem;
}

.steps p {
  margin: 0;
  color: var(--ink-2);
  font-size: 0.98rem;
}

/* ---------- Academy ---------- */

.ladder {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1rem;
}

.ladder li {
  display: flex;
  flex-direction: column;
  padding: 1.5rem;
  background: var(--surface);
  border: 1px solid var(--line);
  border-top: 4px solid var(--accent);
  border-radius: var(--radius);
}

.ladder li:nth-child(1) {
  --step: 0;
}

.ladder li:nth-child(2) {
  --step: 1;
}

.ladder li:nth-child(3) {
  --step: 2;
}

.ladder li:nth-child(n + 4) {
  --step: 3;
}

/* Cards stretch to the row, so the bottoms line up and the tops climb. */
@media (min-width: 60rem) {
  .ladder {
    grid-auto-flow: column;
    grid-auto-columns: minmax(0, 1fr);
  }

  .ladder li {
    margin-top: calc((3 - var(--step)) * 2.25rem);
  }
}

.level {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 0.4rem;
}

.ladder h3 {
  margin-bottom: 0.25rem;
}

.ladder h3 + p:not(.level-meta) {
  margin-top: 0.75rem;
}

.ladder li > p:last-child {
  margin-bottom: 0;
}

.level-meta {
  color: var(--muted);
  font-size: 0.9rem;
  margin-bottom: 1rem;
}

.ladder li > p:not(.level):not(.level-meta):not(.exit) {
  color: var(--ink-2);
  font-size: 0.98rem;
}

.exit {
  margin: auto 0 0;
  padding-top: 1rem;
  border-top: 1px dashed var(--line-strong);
  font-size: 0.95rem;
}

.exit span {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 0.2rem;
}

.academy-notes {
  display: grid;
  gap: 1rem 3rem;
  margin-top: 2.5rem;
  color: var(--ink-2);
}

@media (min-width: 60rem) {
  .academy-notes {
    grid-template-columns: 1fr 1fr;
  }
}

.academy-notes p {
  margin: 0;
}

.academy-notes p:last-child {
  font-family: var(--font-serif);
  font-size: 1.3rem;
  line-height: 1.4;
  color: var(--ink);
  text-wrap: balance;
}

/* ---------- Brief band ---------- */

.section-band {
  background: var(--band-bg);
  color: var(--band-ink);
}

.section-band .eyebrow {
  color: var(--band-accent);
}

.section-band p {
  color: var(--band-muted);
}

.band {
  display: grid;
  gap: 2rem 4rem;
  align-items: end;
}

@media (min-width: 60rem) {
  .band {
    grid-template-columns: minmax(0, 1fr) auto;
  }
}

.band .toc-list {
  columns: 15rem 3;
  column-gap: 2rem;
  list-style: none;
  margin: 0;
  padding: 0;
  font-size: 0.95rem;
}

.band .toc-list li {
  break-inside: avoid;
  padding: 0.2rem 0;
}

.band .toc-list a {
  color: var(--band-ink);
  text-decoration-color: var(--band-line);
}

.band .toc-list a:hover {
  text-decoration-color: currentColor;
}

.section-band .button {
  background: transparent;
  color: var(--band-ink);
  border-color: var(--band-line);
}

.section-band .button:hover {
  border-color: var(--band-ink);
  color: var(--band-ink);
}

.section-band .button-primary {
  background: var(--band-accent);
  border-color: var(--band-accent);
  color: #0b1a13;
}

.section-band .button-primary:hover {
  background: #8be3bb;
  border-color: #8be3bb;
  color: #0b1a13;
}

.section-band :focus-visible {
  outline-color: var(--band-accent);
}

@media screen and (prefers-color-scheme: dark) {
  .section-band {
    border-top: 1px solid var(--line);
  }
}

/* ---------- Document pages ---------- */

.doc-layout {
  display: grid;
  gap: 2rem 4rem;
  padding-block: clamp(2rem, 1.5rem + 3vw, 4.5rem) clamp(3.5rem, 2.5rem + 4vw, 6.5rem);
}

@media (min-width: 64rem) {
  .doc-layout.has-toc {
    grid-template-columns: 15rem minmax(0, 1fr);
  }
}

.doc {
  min-width: 0;
  max-width: 46rem;
}

.doc-meta {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 0.25rem 1rem;
  margin-bottom: 1.25rem;
  font-size: 0.9rem;
}

.doc-meta .eyebrow {
  margin: 0;
}

.doc-meta a {
  color: var(--muted);
}

.doc-meta a:hover {
  color: var(--ink);
}

.doc-aside {
  display: none;
}

@media (min-width: 64rem) {
  .doc-aside {
    display: block;
  }

  .toc-narrow {
    display: none;
  }
}

.toc-wide {
  position: sticky;
  top: calc(var(--header-h) + 1.5rem);
  max-height: calc(100vh - var(--header-h) - 3rem);
  overflow-y: auto;
  padding-right: 0.5rem;
}

.toc-title {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 0.75rem;
}

.toc .toc-list {
  list-style: none;
  margin: 0;
  padding: 0;
  font-size: 0.9rem;
  line-height: 1.4;
  border-left: 1px solid var(--line);
}

.toc .toc-list a {
  display: block;
  padding: 0.35rem 0 0.35rem 0.9rem;
  margin-left: -1px;
  border-left: 2px solid transparent;
  color: var(--ink-2);
  text-decoration: none;
}

.toc .toc-list a:hover {
  color: var(--ink);
  border-left-color: var(--line-strong);
}

.toc .toc-list a:focus-visible {
  outline-offset: -3px;
}

.toc-narrow {
  margin: 0 0 2rem;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  background: var(--surface);
}

.toc-narrow summary {
  padding: 0.8rem 1rem;
  font-weight: 600;
  cursor: pointer;
}

.toc-narrow nav {
  padding: 0 1rem 1rem;
}

/* Long-form text rendered from Markdown */

.prose {
  font-size: 1.0625rem;
  line-height: 1.75;
  overflow-wrap: break-word;
}

.prose > :first-child {
  margin-top: 0;
}

.prose h1 {
  font-size: clamp(2rem, 1.5rem + 2.2vw, 3rem);
  margin-bottom: 1.5rem;
}

.prose h1 + p {
  font-size: 1.15rem;
  color: var(--ink-2);
}

.prose h2 {
  font-size: clamp(1.5rem, 1.25rem + 1vw, 1.95rem);
  margin: 3rem 0 1rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--line);
}

.prose h3 {
  font-size: 1.3rem;
  margin: 2.25rem 0 0.75rem;
}

.prose ul,
.prose ol {
  padding-left: 1.4rem;
  margin: 0 0 1.25rem;
}

.prose li {
  margin-bottom: 0.45rem;
}

.prose li::marker {
  color: var(--muted);
}

.prose blockquote {
  margin: 1.5rem 0;
  padding: 0.25rem 0 0.25rem 1.25rem;
  border-left: 3px solid var(--line-strong);
  color: var(--ink-2);
}

.prose pre {
  margin: 1.25rem 0;
  padding: 1rem 1.2rem;
  border-radius: var(--radius-sm);
  background: var(--code-bg);
}

.prose table {
  width: 100%;
  border-collapse: collapse;
  margin: 1.5rem 0;
  font-size: 0.95rem;
  display: block;
  overflow-x: auto;
}

.prose th,
.prose td {
  padding: 0.6rem 0.75rem;
  border-bottom: 1px solid var(--line);
  text-align: left;
  vertical-align: top;
}

@media (max-width: 40rem) {
  .prose th,
  .prose td {
    padding: 0.5rem 0.4rem;
  }
}

.prose a {
  overflow-wrap: anywhere;
}

.prose hr {
  border: 0;
  border-top: 1px solid var(--line);
  margin: 2.5rem 0;
}

/* ---------- Footer ---------- */

.site-footer {
  border-top: 1px solid var(--line);
  padding-block: 3rem;
  color: var(--ink-2);
  font-size: 0.95rem;
}

.doc-page .site-footer,
.page .site-footer {
  background: var(--surface-2);
}

.site-footer-inner {
  display: grid;
  gap: 1.5rem 3rem;
}

@media (min-width: 60rem) {
  .site-footer-inner {
    grid-template-columns: minmax(0, 1fr) auto;
  }

  .site-footer-source {
    grid-column: 1 / -1;
  }
}

.site-footer-about p {
  margin: 0 0 0.4rem;
}

.site-footer-about .brand {
  font-size: 1.1rem;
  margin-bottom: 0.6rem;
}

.site-footer-nav ul {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 1.5rem;
  list-style: none;
  margin: 0;
  padding: 0;
}

.site-footer-nav a {
  color: var(--ink-2);
}

.site-footer-nav a:hover {
  color: var(--ink);
}

.site-footer-source {
  margin: 0;
  padding-top: 1.5rem;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 0.875rem;
}

.site-footer-source a {
  color: var(--muted);
}

.site-footer-source a:hover {
  color: var(--ink);
}

/* ---------- Print ---------- */

@media print {
  .site-header,
  .site-footer,
  .doc-aside,
  .toc-narrow,
  .skip-link,
  .actions,
  .hero::before {
    display: none !important;
  }

  body {
    display: block;
    background: #fff;
    color: #000;
    font-size: 11pt;
  }

  .section,
  .section-alt,
  .section-band {
    padding-block: 1.5rem;
    background: none;
    color: #000;
    border: 0;
  }

  .section-band p,
  .section-band h2,
  .band .toc-list a {
    color: #000;
  }

  .ships li,
  .card,
  .steps li,
  .ladder li,
  .pilot,
  .checklist li {
    break-inside: avoid;
    box-shadow: none;
  }

  .ladder li {
    margin-top: 0 !important;
  }

  .section-head {
    break-inside: avoid;
    break-after: avoid;
  }

  .subhead,
  .subhead-text,
  h2,
  h3 {
    break-after: avoid;
  }

  .doc-layout {
    display: block;
    padding: 0;
  }

  .prose a::after {
    content: " (" attr(href) ")";
    font-size: 0.85em;
    color: #444;
  }
}

/* ---------- Forced colours (Windows high contrast) ---------- */

@media (forced-colors: active) {
  ul.checklist li::after {
    forced-color-adjust: none;
    background-color: CanvasText;
  }

  .more a::after,
  .link-row a::after {
    forced-color-adjust: none;
    background-color: LinkText;
  }
}