:root {
  --content-max-width: 920px;
  --page-padding: 28px;
  --cru-accent: #b45309;
  --cru-accent-2: #2563eb;
  --cru-border: color-mix(in srgb, var(--fg) 16%, transparent);
  --cru-muted: color-mix(in srgb, var(--fg) 68%, var(--bg));
  --cru-surface: color-mix(in srgb, var(--bg) 94%, var(--fg));
  --cru-code-bg: color-mix(in srgb, var(--bg) 88%, var(--fg));
}

.light,
.rust,
html:not(.js) {
  --links: #b04a08;
  --sidebar-active: #b45309;
  --table-header-bg: #f6eee4;
  --table-alternate-bg: #fbf7f1;
  --quote-bg: #fbf4ea;
  --quote-border: #e6cba6;
}

.ayu,
.coal,
.navy {
  --cru-border: color-mix(in srgb, var(--fg) 22%, transparent);
  --cru-surface: color-mix(in srgb, var(--bg) 86%, var(--fg));
  --cru-code-bg: color-mix(in srgb, var(--bg) 80%, var(--fg));
}

.content main {
  padding-block-start: 22px;
}

.content p,
.content li {
  line-height: 1.62;
}

.content h1,
.content h2,
.content h3 {
  letter-spacing: 0;
}

.content h1 {
  margin-block: 0.55em 0.65em;
  font-size: 3.4rem;
  line-height: 1.12;
}

.content h2 {
  margin-block-start: 2.25em;
  padding-block-start: 0.35em;
  border-block-start: 1px solid var(--cru-border);
  font-size: 2.35rem;
}

.content h3 {
  font-size: 1.78rem;
}

.content a {
  text-underline-offset: 0.18em;
}

.content a:hover {
  text-decoration-thickness: 0.08em;
}

.content code {
  padding: 0.08em 0.28em;
  border-radius: 4px;
  background: var(--cru-code-bg);
}

.content pre code {
  padding: 0;
  background: transparent;
}

.content pre {
  border: 1px solid var(--cru-border);
  border-radius: 8px;
  box-shadow: 0 8px 24px color-mix(in srgb, #000 8%, transparent);
}

.table-wrapper {
  margin-block: 1.25em;
  border: 1px solid var(--cru-border);
  border-radius: 8px;
}

table {
  width: 100%;
}

table th,
table td {
  padding: 0.68em 0.9em;
  vertical-align: top;
}

blockquote {
  border-block: 0;
  border-inline-start: 4px solid var(--quote-border);
  border-radius: 0 8px 8px 0;
}

.sidebar-scrollbox {
  padding-block-start: 0.65rem;
}

.chapter li {
  margin-block: 0.18rem;
}

.chapter li.part-title {
  margin-block-start: 1.25rem;
  color: var(--cru-muted);
  font-size: 1.15rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.menu-title {
  font-weight: 700;
}

.cru-hero {
  margin-block: 0 2rem;
  padding: 1.45rem 1.6rem;
  border: 1px solid var(--cru-border);
  border-radius: 8px;
  background:
    linear-gradient(135deg, color-mix(in srgb, var(--cru-accent) 14%, transparent), transparent 52%),
    var(--cru-surface);
}

.cru-hero .eyebrow {
  margin: 0 0 0.45rem;
  color: var(--cru-accent);
  font-size: 1.2rem;
  font-weight: 800;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.cru-hero .lead {
  margin: 0;
  max-width: 72ch;
  font-size: 1.82rem;
  line-height: 1.5;
}

.cru-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(230px, 1fr));
  gap: 1rem;
  margin-block: 1.25rem;
}

.cru-card {
  padding: 1rem 1.1rem;
  border: 1px solid var(--cru-border);
  border-radius: 8px;
  background: var(--cru-surface);
}

.cru-card h3 {
  margin-block: 0 0.35rem;
}

.cru-card p {
  margin-block: 0;
  color: var(--cru-muted);
}

.cru-callout {
  margin-block: 1.2rem;
  padding: 0.95rem 1.1rem;
  border-inline-start: 4px solid var(--cru-accent-2);
  border-radius: 0 8px 8px 0;
  background: var(--cru-surface);
}

.cru-callout p {
  margin-block: 0;
}

/* Mermaid diagrams: a bordered viewport that svg-pan-zoom drives. Fixed height +
   hidden overflow so the wide flowchart pans/zooms inside the box instead of
   blowing past the content column. */
.mermaid {
  border: 1px solid var(--cru-border, rgba(128, 128, 128, 0.3));
  border-radius: 8px;
  background: var(--cru-surface, rgba(128, 128, 128, 0.04));
  overflow: hidden;
  margin-block: 1.2rem;
}

.mermaid > svg {
  display: block;
}

/* svg-pan-zoom's on-screen zoom controls */
.mermaid .svg-pan-zoom-control {
  opacity: 0.55;
  transition: opacity 0.15s ease;
}

.mermaid:hover .svg-pan-zoom-control {
  opacity: 1;
}

@media (max-width: 700px) {
  :root {
    --page-padding: 18px;
  }

  .content h1 {
    font-size: 2.7rem;
  }

  .cru-hero {
    padding: 1.1rem 1.2rem;
  }
}