/* ---------- Colour scheme ----------
 * Dark by default, light when the OS asks for it, and a saved choice from the
 * toggle (data-theme on <html>) overrides both. Every colour below is a
 * light-dark() pair, so this one property switches the whole site.
 */
:root { color-scheme: dark; }
@media (prefers-color-scheme: light) {
  :root { color-scheme: light; }
}
:root[data-theme="dark"] { color-scheme: dark; }
:root[data-theme="light"] { color-scheme: light; }

:root {
  --bg: light-dark(#fbf8f1, #121417);
  --surface: light-dark(#f1ece1, #1b1e22);
  /* Light code blocks sit on the page colour: the cream surface is too dark for
   * the highlighting theme's colours to keep AA contrast. */
  --code-bg: light-dark(#fbf8f1, #1b1e22);
  --border: light-dark(#e4ddcf, #24282d);
  --text: light-dark(#2a2723, #d9d6cf);
  --heading: light-dark(#15130f, #f3efe6);
  --muted: light-dark(#6f6a62, #8d8a83);
  --accent: light-dark(#1d6f66, #6fc2b8);
  --accent-soft: light-dark(#dcefeb, #1c2b2a);

  --serif: Charter, "Bitstream Charter", "Iowan Old Style", "Sitka Text", Georgia, serif;
  --sans: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  --mono: ui-monospace, "JetBrains Mono", "SF Mono", Menlo, Consolas, monospace;

  --measure: 68ch;
}

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

html {
  font-size: 106.25%; /* 17px */
  -webkit-text-size-adjust: 100%;
}
@media (min-width: 720px) {
  html { font-size: 118.75%; } /* 19px */
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--serif);
  line-height: 1.65;
  text-rendering: optimizeLegibility;
}

a { color: var(--accent); text-decoration-thickness: 1px; text-underline-offset: 0.15em; }
a:hover { text-decoration-thickness: 2px; }

h1, h2, h3, h4 { color: var(--heading); line-height: 1.25; font-weight: 700; }
h1 { font-size: 1.9rem; margin: 0 0 0.4rem; letter-spacing: -0.01em; }
h2 { font-size: 1.35rem; margin: 2.2rem 0 0.6rem; }
h3 { font-size: 1.1rem; margin: 1.8rem 0 0.5rem; }

.meta, .label, .site-header, .site-footer, .toc, .recent, .archive {
  font-family: var(--sans);
}
.meta { color: var(--muted); font-size: 0.8rem; margin: 0 0 1.2rem; }
.label {
  color: var(--muted);
  font-size: 0.68rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  margin: 0 0 0.4rem;
}

main, .site-header, .site-footer {
  width: min(var(--measure), 100% - 2.5rem);
  margin-inline: auto;
}

/* ---------- Header and footer ---------- */
.site-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1.4rem 0 0.9rem;
  margin-bottom: 2.4rem;
  border-bottom: 1px solid var(--border);
}
.brand { font-family: var(--serif); font-weight: 700; font-size: 1.1rem; color: var(--heading); text-decoration: none; }
.site-nav { display: flex; align-items: center; gap: 1.2rem; font-size: 0.8rem; }
.site-nav a { color: var(--muted); text-decoration: none; }
.site-nav a:hover { color: var(--accent); }

#theme-toggle {
  display: inline-grid;
  place-items: center;
  width: 2rem;
  height: 2rem;
  padding: 0;
  border: 1px solid var(--border);
  border-radius: 999px;
  background: transparent;
  color: var(--muted);
  cursor: pointer;
}
#theme-toggle[hidden] { display: none; }
#theme-toggle:hover { color: var(--accent); border-color: var(--accent); }
#theme-toggle svg { width: 1rem; height: 1rem; fill: none; stroke: currentColor; stroke-width: 2; stroke-linecap: round; }
/* Show the icon for the mode you would switch to. */
:root[data-theme="dark"] .icon-moon,
:root[data-theme="light"] .icon-sun { display: none; }

.site-footer {
  margin-top: 4rem;
  padding: 1.2rem 0 2.5rem;
  border-top: 1px solid var(--border);
  color: var(--muted);
  font-size: 0.75rem;
}
.site-footer a { color: inherit; }

/* ---------- Homepage ---------- */
.featured {
  border-left: 3px solid var(--accent);
  padding: 0.2rem 0 0.2rem 1.2rem;
}
.featured h1 a { color: inherit; text-decoration: none; }
.featured h1 a:hover { color: var(--accent); }
.featured .summary p { margin: 0 0 0.8rem; }

.archive { margin-top: 3rem; }
.archive ol { list-style: none; margin: 0; padding: 0; }
.archive li {
  display: flex;
  gap: 1.2rem;
  padding: 0.45rem 0;
  border-bottom: 1px dashed var(--border);
}
.archive time { flex: none; width: 4.5rem; color: var(--muted); font-size: 0.8rem; padding-top: 0.15rem; }
.archive a { font-family: var(--serif); color: var(--text); text-decoration: none; }
.archive a:hover { color: var(--accent); }

/* ---------- Post ---------- */
/* On wide screens the contents list sits in the right margin, outside the reading column.
 * Gap plus width (14rem) must fit the margin at 1200px, or the page scrolls sideways. */
.post-layout { position: relative; }
.toc { display: none; }
@media (min-width: 1200px) {
  .toc {
    display: block;
    position: absolute;
    top: 0;
    bottom: 0;
    left: calc(100% + 2.5rem);
    width: 11.5rem;
  }
  .toc .sticky { position: sticky; top: 2rem; }
}
.toc ol { list-style: none; margin: 0; padding: 0 0 0 0.9rem; border-left: 1px solid var(--border); font-size: 0.75rem; line-height: 1.5; }
.toc ol ol { border: 0; padding-left: 0.8rem; }
.toc li { margin: 0.35rem 0; }
.toc a { color: var(--muted); text-decoration: none; }
.toc a:hover, .toc a[aria-current="true"] { color: var(--accent); }

/* Recent posts mirror the contents list, in the left margin. */
.recent { display: none; }
@media (min-width: 1200px) {
  .recent {
    display: block;
    position: absolute;
    top: 0;
    bottom: 0;
    right: calc(100% + 2.5rem);
    width: 11.5rem;
    text-align: right;
  }
  .recent .sticky { position: sticky; top: 2rem; }
}
.recent ol { list-style: none; margin: 0; padding: 0 0.9rem 0 0; border-right: 1px solid var(--border); font-size: 0.75rem; line-height: 1.5; }
.recent li { margin: 0.5rem 0; }
.recent a { color: var(--muted); text-decoration: none; }
.recent a:hover, .recent a[aria-current="page"] { color: var(--accent); }

.prose > :first-child { margin-top: 0; }
.prose p, .prose ul, .prose ol { margin: 0 0 1.1rem; }
.prose li { margin: 0.25rem 0; }
.prose blockquote {
  margin: 1.4rem 0;
  padding: 0 0 0 1.1rem;
  border-left: 3px solid var(--border);
  color: var(--muted);
  font-style: italic;
}
/* Callouts (templates/components/hot_tip.html, story_time.html): text on the left, icon on the right. */
.prose .callout {
  display: flex;
  align-items: center;
  gap: 1.2rem;
  margin: 1.6rem 0;
  padding: 0.9rem 1.1rem;
  border-left: 3px solid var(--callout-color);
  border-radius: 0 6px 6px 0;
  background: var(--callout-bg);
}
.prose .hot-tip { --callout-color: var(--accent); --callout-bg: var(--accent-soft); }
.prose .story-time { --callout-color: light-dark(#c2410c, #fb923c); --callout-bg: light-dark(#f7e9df, #2a211b); }
.prose .callout-body { flex: 1; min-width: 0; }
.prose .callout-body > :last-child { margin-bottom: 0; }
.prose .callout-icon { flex: none; width: 3.4rem; height: 3.4rem; fill: var(--callout-color); opacity: 0.85; }
.prose .callout-icon-cutout { fill: var(--callout-bg); }
.prose .callout-label {
  margin: 0 0 0.35rem;
  color: var(--callout-color);
  font-family: var(--sans);
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}
/* Inline highlight, e.g. <span class="green">GREEN</span>. */
.prose .green { color: light-dark(#15803d, #4ade80); font-weight: 700; }

/* Footnotes use symbols instead of numbers. Relies on bottom_footnotes in zola.toml, which lists the
 * footnotes in reference order, so the nth reference and the nth footnote get the same symbol.
 * A footnote referenced twice would throw the reference symbols off by one. */
@counter-style footnote-symbols {
  system: symbolic;
  symbols: "*" "†" "‡" "§";
  suffix: " ";
}
.prose { counter-reset: footnote-ref; }
.prose .footnote-reference { counter-increment: footnote-ref; }
.prose .footnote-reference a { font-size: 0; text-decoration: none; }
.prose .footnote-reference a::after { content: counter(footnote-ref, footnote-symbols); font-size: 0.8rem; }
.prose .footnotes { font-size: 0.9rem; color: var(--muted); }
.prose .footnotes-list { list-style: footnote-symbols; }
.prose img { display: block; max-width: 100%; height: auto; margin-inline: auto; }
.prose hr { border: 0; border-top: 1px solid var(--border); margin: 2.4rem 0; }

.prose h2, .prose h3 { position: relative; }
.anchor {
  position: absolute;
  left: -1.1em;
  color: var(--muted);
  text-decoration: none;
  opacity: 0;
}
.prose h2:hover .anchor, .prose h3:hover .anchor, .anchor:focus { opacity: 1; }
@media (max-width: 719px) {
  .anchor { display: none; }
}

/* ---------- Code ---------- */
code { font-family: var(--mono); font-size: 0.85em; }
:not(pre) > code {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 0.05em 0.3em;
}

pre {
  margin: 1.4rem 0;
  padding: 0.9rem 1.1rem;
  overflow-x: auto;
  border: 1px solid var(--border);
  border-radius: 6px;
  background: var(--code-bg);
  font-size: 0.85rem;
  line-height: 1.55;
}
pre code { font-size: inherit; }

/* Zola writes an inline `color-scheme: light dark` on every code block, which
 * would make code follow the OS instead of the toggle. Inherit the page's
 * scheme instead, and use the site's code background rather than the theme's own. */
pre.giallo {
  color-scheme: inherit !important;
  background-color: var(--code-bg) !important;
}

/* Required by Zola's highlighter. */
.giallo-l { display: inline-block; min-height: 1lh; width: 100%; }
.giallo-ln {
  display: inline-block;
  user-select: none;
  margin-right: 0.4em;
  padding: 0.4em;
  min-width: 3ch;
  text-align: right;
  opacity: 0.8;
}

/* ---------- Merge demo ---------- */
.merge-demo,
.bisect-demo {
  --merge-plain: #6b7280;
  --merge-base: #0f766e;
  --merge-alice: #c2410c;
  --merge-bob: #7e22ce;
  margin: 1.8rem 0;
  padding: 1.2rem 1.2rem 0.9rem;
  border: 1px solid var(--border);
  border-radius: 6px;
  background: var(--surface);
  font-family: var(--sans);
}
.prose .merge-demo-heading,
.prose .bisect-demo-heading {
  margin: 0 0 1.1rem;
  padding-bottom: 0.7rem;
  border-bottom: 1px solid var(--border);
  color: var(--heading);
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-align: center;
  text-transform: uppercase;
}
/* Tall enough for the longest file, so the caption and buttons don't jump between steps. */
.merge-demo-stage {
  position: relative;
  display: flex;
  justify-content: center;
  gap: 1.6rem;
  min-height: 22.4rem;
}
.merge-demo-column { display: flex; flex-direction: column; align-items: center; gap: 0.35rem; min-width: 0; }
.merge-demo-title { color: var(--muted); font-size: 0.7rem; line-height: 1.3; min-height: 1.4rem; text-align: center; white-space: nowrap; }
.merge-demo-title > span { font-weight: 700; }
/* Under the commit graph every title is two lines (branch and change), so the rows of lines align. */
.merge-demo-lanes + .merge-demo-title { min-height: 2.6em; }
.merge-demo-title > .is-base,
.merge-demo-title > .is-merge { color: var(--merge-base); }
.merge-demo-title > .is-alice { color: var(--merge-alice); }
.merge-demo-title > .is-bob { color: var(--merge-bob); }

/* Commit graph: a node above each column, on one of three lanes (trunk, alice, bob), joined by SVG edges drawn behind them. */
.merge-demo-lanes { position: relative; width: 100%; height: 3.2rem; }
.merge-demo-node {
  position: absolute;
  left: 50%;
  z-index: 1;
  width: 0.8rem;
  height: 0.8rem;
  margin-left: -0.4rem;
  border-radius: 50%;
}
.merge-demo-node.lane-0 { top: 0.2rem; }
.merge-demo-node.lane-1 { top: 1.2rem; }
.merge-demo-node.lane-2 { top: 2.2rem; }
.merge-demo-node.is-base { background: var(--merge-base); }
.merge-demo-node.is-alice { background: var(--merge-alice); }
.merge-demo-node.is-bob { background: var(--merge-bob); }
/* A merge commit: a ring, so it stands out from ordinary commits on trunk. */
.merge-demo-node.is-merge { border: 3px solid var(--merge-base); background: var(--surface); }
.merge-demo-graph { position: absolute; inset: 0; width: 100%; height: 100%; overflow: visible; pointer-events: none; }
.merge-demo-graph path { fill: none; stroke-width: 2.5; }
.merge-demo-graph .is-alice { stroke: var(--merge-alice); }
.merge-demo-graph .is-bob { stroke: var(--merge-bob); }
.merge-demo-graph .is-base { stroke: var(--merge-base); }
.merge-demo-line {
  display: grid;
  place-items: center;
  grid-auto-flow: column;
  min-width: 2.6rem;
  height: 2rem;
  padding: 0 0.5rem;
  border-radius: 4px;
  color: #fff;
  font-family: var(--mono);
  font-weight: 700;
  font-size: 0.85rem;
}
.merge-demo-line sub { display: none; font-size: 0.65em; opacity: 0.85; }
.merge-demo-line.show-tag sub { display: inline; }
.merge-demo-line.is-plain { background: var(--merge-plain); }
.merge-demo-line.is-base { background: var(--merge-base); }
.merge-demo-line.is-alice { background: var(--merge-alice); }
.merge-demo-line.is-bob { background: var(--merge-bob); }
.merge-demo-line.is-context { color: var(--muted); font-weight: 400; }
/* Each column's lines sit in a card titled after the file, so it reads as the file at that commit. */
.merge-demo-file {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.35rem;
  padding: 0.3rem 0.4rem 0.4rem;
  border: 1px solid var(--border);
  border-radius: 4px;
  background: var(--bg);
}
.merge-demo-file-name { color: var(--muted); font-family: var(--mono); font-size: 0.6rem; }
.merge-demo figcaption,
.bisect-demo figcaption {
  min-height: 3.2em;
  margin-top: 0.6rem;
  color: var(--text);
  font-size: 0.8rem;
  line-height: 1.6;
  text-align: center;
}
.merge-demo-controls,
.bisect-demo-controls {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 1rem;
  margin-top: 0.6rem;
  color: var(--muted);
  font-size: 0.75rem;
}
.merge-demo-controls[hidden],
.bisect-demo-controls[hidden] { display: none; }
@media (max-width: 719px) {
  .merge-demo,
  .bisect-demo { padding-inline: 0.6rem; }
  .merge-demo-stage { gap: 0.6rem; }
}
.merge-demo-controls button,
.bisect-demo-controls button {
  padding: 0.3rem 0.8rem;
  border: 1px solid var(--border);
  border-radius: 999px;
  background: var(--bg);
  color: var(--text);
  font: inherit;
  cursor: pointer;
}
.merge-demo-controls button:hover:not(:disabled),
.bisect-demo-controls button:hover:not(:disabled) { color: var(--accent); border-color: var(--accent); }
.merge-demo-controls button:disabled,
.bisect-demo-controls button:disabled { opacity: 0.4; cursor: default; }

/* ---------- Bisect demo ---------- */
/* Shares the frame, heading, caption and buttons with the merge demo above. */
.bisect-demo {
  --bisect-good: light-dark(#0b7a0b, #2fae2f);
  --bisect-bad: light-dark(#c62f2f, #e06060);
}
.bisect-demo-stage { min-height: 17rem; }
/* The commit row: one equal-width cell per commit, so the HEAD marker and the
 * suspect bracket can be placed by percentage and slide between steps. */
.bisect-demo-track { position: relative; padding: 1.7rem 0 2rem; }
.bisect-demo-row { position: relative; display: grid; grid-template-columns: repeat(17, 1fr); }
.bisect-demo-row::before {
  content: "";
  position: absolute;
  top: 50%;
  left: 2%;
  right: 2%;
  border-top: 2px solid var(--border);
}
.bisect-demo-cell { position: relative; display: flex; justify-content: center; }
.bisect-demo-commit {
  position: relative;
  display: grid;
  place-items: center;
  width: min(1.3rem, 100%);
  aspect-ratio: 1;
  border: 2px solid var(--muted);
  border-radius: 50%;
  background: var(--surface);
  color: #fff;
  font-size: 0.7rem;
  font-weight: 700;
  line-height: 1;
  transition: background-color 0.3s, border-color 0.3s, opacity 0.3s, box-shadow 0.3s;
}
.bisect-demo-commit.is-cleared { border-color: var(--border); background: var(--border); opacity: 0.6; }
.bisect-demo-commit.is-good { border-color: var(--bisect-good); background: var(--bisect-good); }
.bisect-demo-commit.is-bad { border-color: var(--bisect-bad); background: var(--bisect-bad); }
.bisect-demo-commit.is-skip { border-color: var(--muted); background: var(--muted); }
.bisect-demo-commit.is-culprit {
  border-color: var(--bisect-bad);
  background: var(--bisect-bad);
  box-shadow: 0 0 0 3px var(--surface), 0 0 0 5px var(--bisect-bad);
}
.bisect-demo-tag {
  position: absolute;
  top: 100%;
  margin-top: 0.3rem;
  color: var(--muted);
  font-family: var(--mono);
  font-size: 0.65rem;
  white-space: nowrap;
}
.bisect-demo-head,
.bisect-demo-bracket { position: absolute; transition: left 0.45s cubic-bezier(0.2, 0.8, 0.2, 1), width 0.45s cubic-bezier(0.2, 0.8, 0.2, 1); }
.bisect-demo-head { top: 0; display: flex; justify-content: center; }
.bisect-demo-head span {
  display: flex;
  flex-direction: column;
  align-items: center;
  color: var(--accent);
  font-family: var(--mono);
  font-size: 0.65rem;
  font-weight: 700;
  white-space: nowrap;
}
.bisect-demo-head span::after { content: "▾"; line-height: 1; }
/* Sits below the tags, as a line with end ticks over the suspects. */
.bisect-demo-bracket {
  bottom: 0;
  height: 0.45rem;
  border: 2px solid var(--accent);
  border-top: 0;
  border-radius: 0 0 4px 4px;
}
.bisect-demo-bracket[hidden] { display: none; }
.bisect-demo-suspects {
  position: absolute;
  top: 100%;
  left: 50%;
  transform: translateX(-50%);
  margin-top: 0.15rem;
  color: var(--accent);
  font-size: 0.7rem;
  font-weight: 700;
  white-space: nowrap;
}
.prose .bisect-demo-checkout {
  margin: 1.6rem 0 0.6rem;
  color: var(--text);
  font-size: 0.8rem;
  text-align: center;
}
.bisect-demo-checkout code { margin-right: 0.1rem; }
.bisect-demo-label {
  margin-right: 0.5rem;
  color: var(--muted);
  font-size: 0.7rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}
.bisect-demo-result { margin-left: 0.6rem; font-weight: 700; }
.bisect-demo-result.is-good { color: var(--bisect-good); }
.bisect-demo-result.is-bad { color: var(--bisect-bad); }
.bisect-demo-result.is-skip { color: var(--muted); }
/* Tall enough for the longest step, so the caption and buttons don't jump. */
.prose .bisect-demo-term {
  min-height: 9.6rem;
  margin: 0;
  padding: 0.7rem 0.9rem;
  overflow-x: auto;
  border: 1px solid var(--border);
  border-radius: 4px;
  background: var(--code-bg);
  font-family: var(--mono);
  font-size: 0.72rem;
  line-height: 1.6;
}
.bisect-demo-term .is-cmd { color: var(--heading); font-weight: 700; }
.bisect-demo-term .is-out { color: var(--text); }
.bisect-demo-term .is-comment { color: var(--muted); }
/* The longest captions run to three lines, and on narrow screens the caption and the
 * checked-out line wrap further, so the buttons don't jump between steps. */
.bisect-demo figcaption { min-height: 4.8em; }
@media (max-width: 719px) {
  .bisect-demo figcaption { min-height: 9.6em; }
  .prose .bisect-demo-checkout { min-height: 3.2em; }
}
@media (prefers-reduced-motion: reduce) {
  .bisect-demo-commit,
  .bisect-demo-head,
  .bisect-demo-bracket { transition: none; }
}

/* ---------- 404 ---------- */
.not-found { padding: 2rem 0; }