:root {
  --bg: #0b1018;
  --bg-elev: #121a28;
  --bg-soft: #1a2436;
  --text: #e9eef8;
  --text-muted: #aab8d0;
  --line: #2a3550;
  --accent: #4fd1c5;
  --accent-strong: #2fb0a4;
  --serif: "Source Serif 4", "Iowan Old Style", "Palatino Linotype", serif;
  --sans: "IBM Plex Sans", "Segoe UI", sans-serif;
  --mono: "IBM Plex Mono", "Cascadia Code", monospace;
}
* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body {
  background: radial-gradient(circle at 15% 0%, #122038 0%, var(--bg) 45%);
  color: var(--text);
  font-family: var(--sans);
  line-height: 1.6;
}
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }
.wrap { width: min(1100px, calc(100% - 2rem)); margin: 0 auto; }
.site-header {
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(6px);
  position: sticky;
  top: 0;
  background: color-mix(in srgb, var(--bg) 84%, transparent);
}
.site-header .wrap { display: flex; justify-content: space-between; align-items: center; padding: .9rem 0; }
.brand { color: var(--text); font-weight: 700; letter-spacing: .04em; }
.site-header nav { display: flex; gap: 1rem; font-size: .95rem; }
.site-header nav a { color: var(--text-muted); }
.site-header nav a:hover { color: var(--text); }
main.wrap { padding: 2.5rem 0 4rem; }
.hero h1 { font-size: clamp(2rem, 5vw, 3.5rem); line-height: 1.1; margin: .4rem 0 1rem; }
.eyebrow { color: var(--accent); letter-spacing: .08em; text-transform: uppercase; font-size: .75rem; font-weight: 700; }
.subtitle { color: var(--text-muted); max-width: 70ch; }
.cta { display: flex; flex-wrap: wrap; gap: .7rem; margin-top: 1.2rem; }
.btn {
  border: 1px solid var(--line);
  background: var(--bg-elev);
  color: var(--text);
  padding: .6rem .95rem;
  border-radius: .45rem;
  font-size: .93rem;
}
.btn.primary { background: var(--accent); color: #05221e; border-color: var(--accent-strong); font-weight: 700; }
.cards { display: grid; grid-template-columns: repeat(auto-fit, minmax(230px,1fr)); gap: 1rem; margin-top: 2rem; }
.card { background: color-mix(in srgb, var(--bg-elev) 92%, transparent); border: 1px solid var(--line); padding: 1rem; border-radius: .65rem; }
.card h2 { margin: 0 0 .5rem; font-size: 1.05rem; }
.card p { margin: 0; color: var(--text-muted); font-size: .94rem; }
.doc-layout { display: grid; grid-template-columns: 260px 1fr; gap: 2rem; align-items: start; }
.sidebar { position: sticky; top: 4.5rem; padding: 1rem; border: 1px solid var(--line); background: var(--bg-elev); border-radius: .65rem; }
.sidebar h2 { margin-top: 0; font-size: .95rem; text-transform: uppercase; letter-spacing: .08em; color: var(--text-muted); }
.sidebar ul { list-style: none; padding: 0; margin: 0; display: grid; gap: .35rem; }
.sidebar .toc { list-style: none; padding-left: 0; }
.sidebar .toc-l2 { margin-left: .6rem; }
.sidebar .toc-l3 { margin-left: 1.2rem; }
.prose { font-family: var(--serif); max-width: 86ch; }
.prose h1, .prose h2, .prose h3, .prose h4 { font-family: var(--sans); line-height: 1.25; margin-top: 1.8rem; }
.prose h1 { font-size: 2rem; }
.prose h2 { font-size: 1.5rem; border-top: 1px solid var(--line); padding-top: 1rem; }
.prose p, .prose li, .prose td, .prose th { color: #d9e2f1; }
.prose pre { background: #0a1220; border: 1px solid var(--line); border-radius: .55rem; padding: .85rem; overflow-x: auto; font-family: var(--mono); }
.prose code { font-family: var(--mono); background: #0a1220; border: 1px solid #1f2c45; border-radius: .25rem; padding: .1rem .3rem; font-size: .9em; }
.prose table { width: 100%; border-collapse: collapse; margin: 1rem 0; font-size: .95rem; }
.prose th, .prose td { border: 1px solid var(--line); padding: .5rem; }
.prose th { background: var(--bg-soft); text-align: left; }
.spec-banner { background: #11243d; border: 1px solid #28466e; padding: .75rem; border-radius: .6rem; margin-bottom: 1.2rem; }
.post-card { border: 1px solid var(--line); border-radius: .6rem; padding: 1rem; margin-bottom: .85rem; background: var(--bg-elev); }
.site-footer { border-top: 1px solid var(--line); padding: 1.2rem 0 2.2rem; color: var(--text-muted); font-size: .9rem; }
@media (max-width: 900px) {
  .doc-layout { grid-template-columns: 1fr; }
  .sidebar { position: static; }
}
@media print {
  .site-header, .site-footer, .sidebar { display: none !important; }
  body { background: white; color: black; }
  .prose { max-width: 100%; }
}