// The site's one stylesheet, in the manner of the International
// Typographic Style: a neo-grotesque, a strict grid, hairline rules, flush
// left, no ornament, and one colour, blue, used for what matters.
//
// Colours are tokens on :root, redefined for the dark theme, which follows
// the system unless the reader picked one.

// Inter, variable in weight and optical size, and JetBrains Mono; served
// from the site itself (see static/fonts/README.md).
@font-face {
  font-family: "Inter";
  src: url("fonts/InterVariable.woff2") format("woff2");
  font-weight: 100 900;
  font-style: normal;
  font-display: swap;
}
@font-face {
  font-family: "JetBrains Mono";
  src: url("fonts/JetBrainsMono-Regular.woff2") format("woff2");
  font-weight: 400;
  font-style: normal;
  font-display: swap;
}
@font-face {
  font-family: "JetBrains Mono";
  src: url("fonts/JetBrainsMono-Medium.woff2") format("woff2");
  font-weight: 500 700;
  font-style: normal;
  font-display: swap;
}

:root {
  color-scheme: light;

  --bg: #ffffff;
  --bg-tint: #f3f6fb;         // code, the panels
  --bg-hover: #eef2f9;
  --ink: #0a1b33;             // headings, the strong rules
  --text: #26354d;
  --muted: #687891;
  --rule: #dce3ee;
  --rule-strong: #0a1b33;

  --blue: #1f45e0;            // links, marks, the one colour
  --blue-deep: #0b2fa8;       // International Klein Blue, near enough
  --blue-tint: #e9eefc;
  --on-blue: #ffffff;
  --signal: #d4372c;          // caution, used once in a while

  // Code.
  --tok-comment: #8794a8;
  --tok-string: #0b2fa8;
  --tok-constant: #1f45e0;
  --tok-tag: #0a1b33;
  --tok-field: #43577a;
  --tok-keyword: #0b2fa8;

  --display: "Inter", "Helvetica Neue", Helvetica, Arial, sans-serif;
  --sans: "Inter", "Helvetica Neue", Helvetica, Arial, sans-serif;
  --mono: "JetBrains Mono", "SF Mono", ui-monospace, Menlo, Consolas, monospace;

  --topbar: 56px;
  --gutter: 32px;
}

@mixin dark {
  color-scheme: dark;

  --bg: #06101e;
  --bg-tint: #0b1729;
  --bg-hover: #0f1d33;
  --ink: #f1f5fc;
  --text: #c8d2e2;
  --muted: #8291a9;
  --rule: #18263b;
  --rule-strong: #c8d2e2;

  --blue: #7095ff;
  --blue-deep: #2a4fe0;
  --blue-tint: #0f2142;
  --on-blue: #ffffff;
  --signal: #ff6b5e;

  --tok-comment: #5f6f88;
  --tok-string: #9fb6ff;
  --tok-constant: #7095ff;
  --tok-tag: #f1f5fc;
  --tok-field: #b4c1d6;
  --tok-keyword: #9fb6ff;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) { @include dark; }
}
:root[data-theme="dark"] { @include dark; }

// ---------------------------------------------------------------------------
// Base

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

html {
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
  scroll-padding-top: calc(var(--topbar) + 24px);
}

body {
  margin: 0;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  background: var(--bg);
  color: var(--text);
  font: 15.5px/1.65 var(--sans);
  font-feature-settings: "cv11", "ss01";
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

a { color: inherit; text-decoration: none; }
img, svg { display: block; }
.icon { flex: none; }
code, kbd, pre { font-family: var(--mono); }
button { font: inherit; color: inherit; }

::selection { background: var(--blue); color: var(--on-blue); }

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

.skip {
  position: absolute;
  left: 12px;
  top: -48px;
  z-index: 100;
  padding: 8px 14px;
  background: var(--blue);
  color: var(--on-blue);
  &:focus { top: 12px; }
}

kbd {
  display: inline-flex;
  align-items: center;
  font-size: 11px;
  line-height: 1;
  padding: 3px 5px;
  border: 1px solid var(--rule);
  color: var(--muted);
}

// A small label in the monospace: section numbers and the like.
.eyebrow {
  display: block;
  margin: 0 0 12px;
  font: 500 12px/1.4 var(--mono);
  color: var(--blue);
}

// ---------------------------------------------------------------------------
// Top bar

.topbar {
  position: sticky;
  top: 0;
  z-index: 40;
  height: var(--topbar);
  background: var(--bg);
  border-bottom: 1px solid var(--rule-strong);
}

.topbar-inner {
  height: 100%;
  padding: 0 var(--gutter);
  display: flex;
  align-items: center;
  gap: 40px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font: 600 18px/1 var(--display);
  letter-spacing: -0.02em;
  color: var(--ink);
}
.brand-mark { width: 12px; height: 12px; background: var(--blue); }
.brand-version { font: 400 12px var(--mono); letter-spacing: 0; color: var(--muted); }

.topnav {
  display: flex;
  gap: 28px;
  a {
    font-size: 14px;
    color: var(--muted);
    &:hover { color: var(--ink); }
    &[aria-current="page"] { color: var(--ink); }
  }
}

.topbar-actions {
  margin-left: auto;
  display: flex;
  align-items: center;
  gap: 4px;
}

.search-button {
  display: flex;
  align-items: center;
  gap: 10px;
  width: 220px;
  height: 34px;
  padding: 0 8px 0 10px;
  margin-right: 12px;
  border: 1px solid var(--rule);
  background: transparent;
  color: var(--muted);
  font-size: 13.5px;
  cursor: pointer;
  &:hover { border-color: var(--muted); }
  .search-button-key { margin-left: auto; }
}

.icon-button {
  display: inline-grid;
  place-items: center;
  width: 34px;
  height: 34px;
  border: 0;
  background: transparent;
  color: var(--muted);
  cursor: pointer;
  &:hover { color: var(--ink); }
}

.menu-button { display: none; margin-left: -8px; }

// The icon for the theme one would switch to.
.theme-icon-light { display: none; }
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) .theme-icon-light { display: block; }
  :root:not([data-theme="light"]) .theme-icon-dark { display: none; }
}
:root[data-theme="dark"] .theme-icon-light { display: block; }
:root[data-theme="dark"] .theme-icon-dark { display: none; }

// ---------------------------------------------------------------------------
// Buttons and links

.button {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  height: 46px;
  padding: 0 22px;
  font-size: 15px;
  font-weight: 500;
  border: 1px solid transparent;
  cursor: pointer;
  .icon { width: 16px; height: 16px; transition: transform 0.15s; }
  &:hover .icon { transform: translateX(3px); }
}
.button-primary {
  background: var(--blue-deep);
  color: var(--on-blue);
  &:hover { background: var(--ink); color: var(--bg); }
}
.button-ghost {
  color: var(--ink);
  border-color: var(--rule-strong);
  background: transparent;
  &:hover { background: var(--ink); color: var(--bg); }
}

.text-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-weight: 500;
  color: var(--blue);
  .icon { width: 15px; height: 15px; transition: transform 0.15s; }
  &:hover .icon { transform: translateX(3px); }
}

// ---------------------------------------------------------------------------
// The front page: a poster, then a datasheet, then numbered sections.

.layout-home main { flex: 1; }

.home-section {
  padding: 0 var(--gutter);
  border-top: 1px solid var(--rule-strong);
}
// A section's number and name on the left, its content on a grid to the
// right: the same two columns all the way down the page.
.home-grid {
  display: grid;
  grid-template-columns: 3fr 9fr;
  gap: var(--gutter);
  padding: 28px 0 96px;
}
.home-label {
  font: 600 13px/1.4 var(--display);
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--ink);
  .eyebrow { margin-bottom: 4px; }
}

.hero {
  position: relative;
  min-height: min(calc(100vh - var(--topbar)), 760px);
  display: flex;
  flex-direction: column;
  color: #ffffff;
  background: #0a0c10;
  overflow: hidden;
}

// The photograph in its own colours, a little darker and calmer, with a
// shade on the left that keeps the text legible.
.hero-photo {
  position: absolute;
  inset: 0;
  img {
    position: absolute;
    inset: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
    object-position: 60% 50%;
    filter: saturate(0.85) brightness(0.8);
  }
}
.hero-shade {
  position: absolute;
  inset: 0;
  background: linear-gradient(90deg,
    rgba(10, 12, 16, 0.92) 0%,
    rgba(10, 12, 16, 0.78) 35%,
    rgba(10, 12, 16, 0.35) 65%,
    rgba(10, 12, 16, 0.05) 100%);
}
.hero-copy {
  position: relative;
  flex: 1;
  display: flex;
  flex-direction: column;
  max-width: 820px;
  padding: 96px var(--gutter) 40px;
  .eyebrow { color: #c9d4ff; }
}
.hero-title {
  margin: 0 0 32px;
  font: 700 clamp(52px, 7vw, 100px)/0.96 var(--display);
  letter-spacing: -0.05em;
  color: #ffffff;
}
.hero-text {
  max-width: 33em;
  margin: 0 0 40px;
  font-size: 19px;
  line-height: 1.6;
  color: #e3e9ff;
  code { color: #ffffff; }
}
.hero-actions { display: flex; flex-wrap: wrap; gap: 12px; }
.hero-foot {
  margin-top: auto;
  padding-top: 48px;
  font: 13px var(--mono);
  color: #b8c7ff;
  .prompt { color: #ffffff; margin-right: 8px; user-select: none; }
}
.hero-credit {
  position: relative;
  margin: 0;
  padding: 0 var(--gutter) 20px;
  text-align: right;
  font: 11.5px var(--mono);
  color: rgba(255, 255, 255, 0.7);
  a { color: inherit; text-decoration: underline; text-underline-offset: 2px; }
  a:hover { color: #ffffff; }
}

.button-light {
  background: #ffffff;
  color: var(--blue-deep);
  &:hover { background: #dfe6ff; }
}
.button-outline-light {
  color: #ffffff;
  border-color: rgba(255, 255, 255, 0.75);
  &:hover { background: #ffffff; color: #0a1b33; }
}

.spec {
  margin: 0;
  display: grid;
  grid-template-columns: 1fr 1fr;
  column-gap: var(--gutter);
  div {
    display: grid;
    grid-template-columns: 11em 1fr;
    gap: 16px;
    padding: 13px 0;
    border-bottom: 1px solid var(--rule);
    font-size: 14.5px;
  }
  dt { color: var(--muted); }
  dd { margin: 0; color: var(--ink); }
}

.features {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  column-gap: var(--gutter);
  row-gap: 48px;
}
.feature {
  display: block;
  padding-top: 14px;
  border-top: 1px solid var(--rule-strong);
  h3 {
    margin: 10px 0 8px;
    font: 600 17px/1.3 var(--display);
    letter-spacing: -0.015em;
    color: var(--ink);
  }
  p { margin: 0; font-size: 14.5px; line-height: 1.6; color: var(--muted); }
  code { font-size: 0.9em; color: var(--text); }
  .eyebrow { margin: 0; }
  &:hover h3 { color: var(--blue); }
}

.phases, .checks {
  list-style: none;
  margin: 0 0 28px;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  column-gap: var(--gutter);
  li {
    display: flex;
    gap: 14px;
    padding: 10px 0;
    border-bottom: 1px solid var(--rule);
    font: 14px var(--mono);
    color: var(--ink);
  }
  span { color: var(--muted); }
}
.home-note { max-width: 44em; margin: 0 0 20px; color: var(--text); }
.checks {
  grid-template-columns: repeat(3, 1fr);
  li { font-family: var(--sans); font-size: 15px; }
  span { font: 13px var(--mono); color: var(--blue); }
}

.start {
  display: grid;
  grid-template-columns: 4fr 7fr;
  gap: var(--gutter);
  align-items: start;
  pre {
    margin: 0;
    padding: 22px 24px;
    background: var(--bg-tint);
    font-size: 13px;
    line-height: 1.8;
    color: var(--ink);
    overflow-x: auto;
  }
  .prompt { color: var(--blue); user-select: none; }
  .comment { color: var(--tok-comment); }
  p { margin: 0 0 24px; font-size: 17px; max-width: 30em; }
}

.not-found {
  flex: 1;
  padding: 120px var(--gutter);
  h1 { margin: 0 0 16px; font: 700 64px/1 var(--display); letter-spacing: -0.045em; color: var(--ink); }
  p { margin: 0 0 32px; font-size: 18px; max-width: 30em; }
}

// ---------------------------------------------------------------------------
// The documentation: contents, page, and what is on the page

.docs-layout {
  flex: 1;
  width: 100%;
  display: grid;
  grid-template-columns: 264px minmax(0, 1fr) 236px;
}

.sidebar {
  position: sticky;
  top: var(--topbar);
  height: calc(100vh - var(--topbar));
  overflow-y: auto;
  padding: 32px 24px 48px var(--gutter);
  border-right: 1px solid var(--rule);
  scrollbar-width: thin;
}
.nav-group {
  margin-bottom: 28px;
  ul { list-style: none; margin: 0; padding: 0; }
  li a {
    position: relative;
    display: block;
    padding: 4px 0;
    font-size: 14px;
    color: var(--muted);
    &:hover { color: var(--ink); }
    &[aria-current="page"] {
      color: var(--ink);
      font-weight: 500;
      &::before {
        content: "";
        position: absolute;
        left: -16px;
        top: 50%;
        width: 7px;
        height: 7px;
        margin-top: -3.5px;
        background: var(--blue);
      }
    }
  }
}
.nav-group-title {
  display: flex;
  gap: 10px;
  margin-bottom: 8px;
  font: 600 12px/1.4 var(--display);
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--ink);
  span { font: 500 11.5px var(--mono); letter-spacing: 0; color: var(--blue); }
  &:hover, &[aria-current="page"] { color: var(--blue); }
}

.docs-main {
  min-width: 0;
  padding: 44px 64px 96px;
}

.toc-column { padding: 44px var(--gutter) 48px 0; }
.toc {
  position: sticky;
  top: calc(var(--topbar) + 44px);
  max-height: calc(100vh - var(--topbar) - 88px);
  overflow-y: auto;
  font-size: 13px;
  counter-reset: toc;
  ul { list-style: none; margin: 0; padding: 0; }
  ul ul { padding-left: 26px; }
  > ul > li > a::before {
    counter-increment: toc;
    content: counter(toc, decimal-leading-zero);
    display: inline-block;
    width: 26px;
    font: 11.5px var(--mono);
    color: var(--muted);
  }
  a {
    display: block;
    padding: 4px 0;
    color: var(--muted);
    line-height: 1.45;
    &:hover { color: var(--ink); }
    &.active { color: var(--ink); }
    &.active::before { color: var(--blue) !important; }
  }
}
.toc-title {
  margin: 0 0 12px;
  font: 600 12px var(--display);
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--ink);
}

.page-header {
  margin-bottom: 40px;
  padding-bottom: 32px;
  border-bottom: 1px solid var(--rule);
  h1 {
    margin: 0;
    color: var(--ink);
    font: 680 48px/1.02 var(--display);
    letter-spacing: -0.04em;
  }
  .lead {
    margin: 18px 0 0;
    font-size: 19px;
    line-height: 1.55;
    color: var(--muted);
    text-wrap: pretty;
  }
}

// Text written in Markdown. Its second-level headings are numbered, as the
// contents beside them are.
.prose {
  max-width: 760px;
  font-size: 16px;
  line-height: 1.72;
  color: var(--text);
  counter-reset: h2;

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

  p, ul, ol, table, pre, blockquote, figure, details { margin: 0 0 1.3em; }

  h2, h3, h4 {
    color: var(--ink);
    font-family: var(--display);
    font-weight: 600;
    text-wrap: balance;
    a { color: inherit; text-decoration: none; }
  }
  h2 {
    margin: 2.6em 0 0.8em;
    padding-top: 14px;
    border-top: 1px solid var(--rule-strong);
    font-size: 26px;
    line-height: 1.2;
    letter-spacing: -0.03em;
    &::before {
      counter-increment: h2;
      content: counter(h2, decimal-leading-zero);
      display: block;
      margin-bottom: 10px;
      font: 500 12px var(--mono);
      letter-spacing: 0;
      color: var(--blue);
    }
  }
  .page-header + h2 { margin-top: 0; }
  h3 { margin: 2em 0 0.6em; font-size: 19px; letter-spacing: -0.02em; }
  h4 { margin: 1.6em 0 0.5em; font-size: 16px; }

  a:not(.card) {
    color: var(--blue);
    text-decoration: underline;
    text-decoration-color: color-mix(in srgb, var(--blue) 35%, transparent);
    text-decoration-thickness: 1px;
    text-underline-offset: 3px;
    &:hover { text-decoration-color: currentColor; }
  }

  // A heading is a link to itself, and looks like a heading.
  :is(h2, h3, h4) a { color: inherit !important; text-decoration: none !important; }

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

  ul, ol { padding-left: 1.25em; }
  li { margin: 0.35em 0; padding-left: 0.2em; }
  ul > li::marker { content: "–  "; color: var(--muted); }
  ol > li::marker { font: 500 0.85em var(--mono); color: var(--blue); }
  li > ul, li > ol { margin: 0.35em 0; }

  hr { border: 0; border-top: 1px solid var(--rule); margin: 3em 0; }

  :not(pre) > code {
    padding: 0.12em 0.35em;
    font-size: 0.85em;
    color: var(--ink);
    background: var(--bg-tint);
    white-space: nowrap;
  }
  a code { color: inherit; }

  blockquote {
    padding: 0 0 0 20px;
    border-left: 1px solid var(--rule-strong);
    color: var(--muted);
  }

  table {
    display: block;
    width: max-content;
    max-width: 100%;
    overflow-x: auto;
    border-collapse: collapse;
    font-size: 14.5px;
    line-height: 1.55;
  }
  th, td {
    padding: 10px 20px 10px 0;
    text-align: left;
    vertical-align: top;
    border-bottom: 1px solid var(--rule);
  }
  th {
    padding-top: 0;
    font: 600 11.5px/1.4 var(--display);
    letter-spacing: 0.06em;
    text-transform: uppercase;
    color: var(--ink);
    border-bottom-color: var(--rule-strong);
    white-space: nowrap;
  }
  td code { white-space: normal; overflow-wrap: anywhere; }
  td:first-child code { white-space: nowrap; overflow-wrap: normal; }
  // The type of a configuration field, under its name.
  td .type {
    display: block;
    margin-top: 4px;
    font-size: 12.5px;
    color: var(--muted);
    white-space: nowrap;
  }

  details {
    border-top: 1px solid var(--rule-strong);
    padding: 12px 0;
    summary { cursor: pointer; font-weight: 600; color: var(--ink); }
  }

  // A whole configuration file, with its name above it.
  figure.example {
    margin: 0 0 1.5em;
    figcaption {
      padding: 8px 0;
      font: 12px var(--mono);
      color: var(--muted);
      border-top: 1px solid var(--rule-strong);
    }
    .code-block, pre { margin: 0 !important; }
  }

  figure.diagram {
    padding: 0 0 8px;
    border-top: 1px solid var(--rule-strong);
    overflow-x: auto;
    svg { margin: 24px 0 0; max-width: 100%; height: auto; }
    figcaption { margin-top: 16px; font-size: 14px; color: var(--muted); max-width: 40em; }
    .box { fill: var(--bg); stroke: var(--rule-strong); stroke-width: 1; }
    .box-accent { fill: var(--blue-deep); stroke: var(--blue-deep); }
    .t { fill: var(--ink); font: 600 14px var(--display); }
    .s { fill: var(--muted); font: 12px var(--sans); }
    .t.on-accent, .s.on-accent { fill: var(--on-blue); }
    .edge { fill: none; stroke: var(--ink); stroke-width: 1; }
    .edge-back { stroke: var(--blue); stroke-dasharray: 4 4; }
    .head { fill: var(--ink); }
  }
}

// Code blocks. The highlighter names each token; the colours are ours.
.prose pre {
  position: relative;
  padding: 18px 22px;
  font-size: 13.5px;
  line-height: 1.7;
  color: var(--ink);
  background: var(--bg-tint);
  overflow-x: auto;
  tab-size: 4;
  scrollbar-width: thin;
  code { display: block; min-width: max-content; }
}
.z-comment { color: var(--tok-comment); }
.z-string { color: var(--tok-string); }
.z-constant { color: var(--tok-constant); }
.z-keyword, .z-storage { color: var(--tok-keyword); font-weight: 500; }
.z-entity.z-name.z-tag, .z-entity.z-name { color: var(--tok-tag); font-weight: 500; }
.z-support, .z-variable { color: var(--tok-field); }
.z-punctuation.z-definition.z-comment { color: var(--tok-comment); }

.code-block {
  position: relative;
  margin: 0 0 1.3em;
  pre { margin: 0 !important; }
  &:hover .copy-button { opacity: 1; }
}
.copy-button {
  position: absolute;
  top: 8px;
  right: 8px;
  display: grid;
  place-items: center;
  width: 30px;
  height: 30px;
  border: 1px solid var(--rule);
  background: var(--bg);
  color: var(--muted);
  cursor: pointer;
  opacity: 0;
  transition: opacity 0.15s;
  &:hover { color: var(--ink); border-color: var(--muted); }
  &:focus-visible { opacity: 1; }
  &.copied { color: var(--blue); opacity: 1; }
  .icon { width: 14px; height: 14px; }
}
@media (hover: none) { .copy-button { opacity: 1; } }

// > [!NOTE] and the like, which Zola writes as a blockquote with a class
// and no title: a rule above, the kind in capitals, the text.
.prose blockquote[class^="markdown-alert-"] {
  --alert: var(--blue);
  --alert-title: "Note";
  padding: 12px 0 2px;
  border: 0;
  border-top: 2px solid var(--alert);
  color: var(--text);
  font-size: 15px;
  > :last-child { margin-bottom: 0.6em; }
  &::before {
    content: var(--alert-title);
    display: block;
    margin-bottom: 4px;
    font: 600 11.5px var(--display);
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: var(--alert);
  }
}
.prose blockquote.markdown-alert-tip { --alert-title: "Tip"; }
.prose blockquote.markdown-alert-important { --alert: var(--ink); --alert-title: "Important"; }
.prose blockquote.markdown-alert-warning { --alert: var(--signal); --alert-title: "Warning"; }
.prose blockquote.markdown-alert-caution { --alert: var(--signal); --alert-title: "Caution"; }

// The pages of a group, as a list with rules between.
.cards {
  max-width: 760px;
  margin-bottom: 48px;
  border-top: 1px solid var(--rule-strong);
}
.card {
  display: grid;
  grid-template-columns: 3.6em 1fr;
  gap: 4px 0;
  padding: 16px 0;
  border-bottom: 1px solid var(--rule);
  &:hover .card-title { color: var(--blue); }
}
.card-number { font: 500 12px/1.9 var(--mono); color: var(--blue); grid-row: span 2; }
.card-title {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  font: 600 17px var(--display);
  letter-spacing: -0.015em;
  color: var(--ink);
  .icon { width: 16px; height: 16px; color: var(--muted); }
}
.card-text { font-size: 14.5px; line-height: 1.55; color: var(--muted); }

.group-overview {
  max-width: 760px;
  margin-bottom: 24px;
  h2 {
    display: flex;
    gap: 14px;
    align-items: baseline;
    margin: 0 0 6px;
    font: 600 24px var(--display);
    letter-spacing: -0.03em;
    color: var(--ink);
    span { font: 500 12px var(--mono); color: var(--blue); letter-spacing: 0; }
    a:hover { color: var(--blue); }
  }
  > p { margin: 0 0 16px; color: var(--muted); }
}

.pager {
  max-width: 760px;
  margin-top: 72px;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--gutter);
}
.pager-link {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding-top: 12px;
  border-top: 1px solid var(--rule-strong);
  &:hover .pager-title { color: var(--blue); }
}
.pager-next { text-align: right; grid-column: 2; }
.pager-label { font: 12px var(--mono); color: var(--muted); }
.pager-title { font: 600 18px var(--display); letter-spacing: -0.02em; color: var(--ink); }

.page-source {
  max-width: 760px;
  margin: 32px 0 0;
  font-size: 13px;
  a {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    color: var(--muted);
    &:hover { color: var(--ink); }
  }
  .icon { width: 14px; height: 14px; }
}

// ---------------------------------------------------------------------------
// Footer

.footer { border-top: 1px solid var(--rule-strong); }
.footer-inner {
  padding: 24px var(--gutter);
  display: grid;
  grid-template-columns: 3fr 9fr;
  gap: var(--gutter);
  font-size: 13.5px;
  color: var(--muted);
}
.footer-brand { display: flex; align-items: center; gap: 10px; color: var(--ink); font-weight: 500; }
.footer-links { display: flex; flex-wrap: wrap; gap: 28px; a:hover { color: var(--ink); } }
.footer-links span { margin-left: auto; }

// ---------------------------------------------------------------------------
// Search

.search {
  position: fixed;
  inset: 0;
  z-index: 60;
  display: flex;
  justify-content: center;
  align-items: flex-start;
  padding: 12vh 16px 16px;
  &[hidden] { display: none; }
}
.search-backdrop {
  position: absolute;
  inset: 0;
  background: color-mix(in srgb, var(--ink) 30%, transparent);
  animation: fade-in 0.12s ease;
}
.search-dialog {
  position: relative;
  width: 100%;
  max-width: 640px;
  max-height: 70vh;
  display: flex;
  flex-direction: column;
  background: var(--bg);
  border: 1px solid var(--rule-strong);
  overflow: hidden;
  animation: fade-in 0.12s ease;
}
.search-field {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 0 16px;
  border-bottom: 1px solid var(--rule-strong);
  color: var(--muted);
  input {
    flex: 1;
    height: 56px;
    border: 0;
    outline: 0;
    background: transparent;
    color: var(--ink);
    font: 17px var(--sans);
    &::placeholder { color: var(--muted); }
    &::-webkit-search-cancel-button { display: none; }
  }
  kbd { cursor: pointer; }
}
.search-results {
  list-style: none;
  margin: 0;
  padding: 0;
  overflow-y: auto;
  &:empty { display: none; }
  li { border-bottom: 1px solid var(--rule); }
  a {
    display: block;
    padding: 12px 16px 12px 18px;
    border-left: 3px solid transparent;
    &:hover { background: var(--bg-hover); }
    &[aria-selected="true"] { border-left-color: var(--blue); background: var(--blue-tint); }
    &[aria-selected="true"] .search-result-title { color: var(--blue); }
  }
}
.search-result-section { display: block; font: 11.5px var(--mono); color: var(--muted); margin-bottom: 2px; }
.search-result-title { display: block; font: 600 15.5px var(--display); color: var(--ink); }
.search-result-text {
  display: -webkit-box;
  margin-top: 3px;
  font-size: 13.5px;
  line-height: 1.5;
  color: var(--muted);
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
  mark { background: transparent; color: var(--ink); font-weight: 600; }
}
.search-empty { margin: 0; padding: 28px 18px; color: var(--muted); }

@keyframes fade-in { from { opacity: 0; } }

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

// ---------------------------------------------------------------------------
// Narrower screens

@media (max-width: 1240px) {
  .docs-layout { grid-template-columns: 248px minmax(0, 1fr); }
  .toc-column { display: none; }
  .docs-main { padding: 40px 48px 80px; }
  .features { grid-template-columns: repeat(2, 1fr); }
  .phases { grid-template-columns: repeat(3, 1fr); }
  .checks { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 960px) {
  :root { --gutter: 24px; }
  .topnav { display: none; }
  .menu-button { display: inline-grid; }
  .search-button { width: auto; border: 0; margin-right: 0; }
  .search-button-label, .search-button-key { display: none; }
  .docs-layout { grid-template-columns: minmax(0, 1fr); }
  .sidebar {
    position: fixed;
    top: var(--topbar);
    left: 0;
    bottom: 0;
    z-index: 30;
    width: min(320px, 86vw);
    height: auto;
    padding-left: 40px;
    background: var(--bg);
    border-right: 1px solid var(--rule-strong);
    transform: translateX(-102%);
    transition: transform 0.2s ease;
    visibility: hidden;
  }
  body.menu-open .sidebar { transform: none; visibility: visible; }
  body.menu-open::after {
    content: "";
    position: fixed;
    inset: var(--topbar) 0 0 0;
    z-index: 20;
    background: color-mix(in srgb, var(--ink) 25%, transparent);
  }
  .docs-main { padding: 32px var(--gutter) 64px; }

  .hero { min-height: 0; }
  .hero-copy { padding: 64px var(--gutter) 32px; }
  .hero-shade { background: linear-gradient(180deg, rgba(10, 12, 16, 0.7), rgba(10, 12, 16, 0.9)); }
  .hero-credit { text-align: left; }
  .home-grid { grid-template-columns: minmax(0, 1fr); gap: 20px; padding-bottom: 72px; }
  .spec { grid-template-columns: minmax(0, 1fr); }
  .start { grid-template-columns: minmax(0, 1fr); }
  .footer-inner { grid-template-columns: minmax(0, 1fr); }
}

@media (max-width: 640px) {
  :root { --gutter: 16px; }
  .topbar-inner { gap: 16px; }
  .brand-version { display: none; }
  .page-header h1 { font-size: 36px; }
  .page-header .lead { font-size: 17px; }
  .prose { font-size: 15.5px; }
  .prose h2 { font-size: 22px; }
  .prose pre { font-size: 12.5px; padding: 14px 16px; }
  .hero-text { font-size: 17px; }
  .spec div { grid-template-columns: 9em 1fr; }
  .features { grid-template-columns: minmax(0, 1fr); row-gap: 32px; }
  .phases { grid-template-columns: repeat(2, 1fr); }
  .checks { grid-template-columns: minmax(0, 1fr); }
  .pager { grid-template-columns: minmax(0, 1fr); }
  .pager-next { grid-column: 1; }
}