:root {
  --accent: #6366f1;
  --bg: #0a0a0b;
  --fg: #e4e4e7;
  --muted: #a1a1aa;
  --border: #27272a;
  --code-bg: #18181b;
}
* { box-sizing: border-box; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font: 16px/1.7 -apple-system, BlinkMacSystemFont, system-ui, sans-serif;
}
.topbar {
  position: sticky;
  top: 0;
  display: flex;
  gap: 1rem;
  align-items: center;
  padding: 0.8rem 1.2rem;
  background: var(--bg);
  border-bottom: 1px solid var(--border);
}
.topbar a { color: var(--accent); text-decoration: none; font-size: 0.9rem; }
.layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 15rem;
  gap: 2.5rem;
  max-width: 64rem;
  margin: 0 auto;
  padding: 2rem 1.2rem;
}
.prose { min-width: 0; }
.prose h1, .prose h2, .prose h3 { line-height: 1.25; margin: 1.6em 0 0.6em; }
.prose h1 { font-size: 2rem; margin-top: 0; }
.prose a { color: var(--accent); }
.prose code {
  background: var(--code-bg);
  padding: 0.15em 0.35em;
  border-radius: 4px;
  font-size: 0.9em;
}
.prose pre {
  background: var(--code-bg);
  border: 1px solid var(--border);
  padding: 1rem;
  border-radius: 8px;
  overflow: auto;
}
.prose pre code { background: none; padding: 0; }
.prose img { max-width: 100%; border-radius: 8px; }
.prose blockquote {
  margin: 1em 0;
  padding: 0.2em 1em;
  border-left: 3px solid var(--accent);
  color: var(--muted);
}
.prose table { border-collapse: collapse; }
.prose th, .prose td { border: 1px solid var(--border); padding: 0.4em 0.7em; }
.toc {
  position: sticky;
  top: 4rem;
  align-self: start;
  max-height: 80vh;
  overflow: auto;
  font-size: 0.9rem;
}
.toc ul { list-style: none; margin: 0; padding: 0; border-left: 1px solid var(--border); }
.toc li.h3 { padding-left: 1rem; }
.toc a {
  display: block;
  padding: 0.2em 0.8em;
  margin-left: -1px;
  color: var(--muted);
  text-decoration: none;
  border-left: 2px solid transparent;
}
.toc a:hover { color: var(--fg); border-left-color: var(--accent); }
/* Starter building blocks for inline custom HTML (use, restyle, or ignore). Repeat a class
   string 3+ times in your markdown's HTML → promote it to a class like these. */
.card {
  border: 1px solid var(--border);
  background: rgba(24, 24, 27, 0.4);
  border-radius: 12px;
  padding: 1rem 1.2rem;
}
.pill {
  display: inline-block;
  border-radius: 999px;
  padding: 0.15em 0.7em;
  font-size: 0.8rem;
  background: rgba(99, 102, 241, 0.15); /* accent-tinted */
}
@media (max-width: 760px) {
  .layout { grid-template-columns: 1fr; }
  .toc { display: none; }
}

/* Print / "Save as PDF" — drop the chrome, go black-on-white, avoid mid-heading breaks. */
@media print {
  .topbar, .toc { display: none !important; }
  .layout { display: block; max-width: none; margin: 0; padding: 0; }
  body { background: #fff; color: #111; }
  .prose a { color: #111; text-decoration: underline; }
  .prose pre, .prose code { background: #f4f4f5; color: #111; border-color: #ddd; }
  .prose h1, .prose h2, .prose h3 { break-after: avoid; }
  .prose pre, .mermaid, .prose img, .prose table { break-inside: avoid; }
}