/* docs.tourbillon.ai — documentation stylesheet.
   Tokens and component vocabulary follow T2.StaticSite/DESIGN.md: JetBrains Mono
   for chrome and headings, Inter for body, hairline borders, hard offset shadows,
   rectangular controls, red as the single hot accent. */

:root {
  --bg:      #FCFCFC;
  --ink:     #010003;
  --red:     #E82813;
  --oxide:   #68150A;
  --blue:    #0B78B3;
  --ink-70:  rgba(1, 0, 3, 0.70);
  --ink-55:  rgba(1, 0, 3, 0.55);
  --ink-25:  rgba(1, 0, 3, 0.25);
  --ink-12:  rgba(1, 0, 3, 0.12);
  --ink-08:  rgba(1, 0, 3, 0.08);
  --ink-04:  rgba(1, 0, 3, 0.04);
  --code-bg: #0A0A0C;
  --code-fg: #E8E8E6;
  --mono: 'JetBrains Mono', 'SF Mono', Menlo, Consolas, monospace;
  --sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --nav-h: 64px;
  --side-w: 248px;
  --toc-w: 200px;
  --maxw: 1240px;
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: calc(var(--nav-h) + 24px); }
::selection { background: var(--ink); color: var(--bg); }
body {
  font-family: var(--sans);
  font-weight: 450;
  font-size: 15px;
  background-color: var(--bg);
  background-image: radial-gradient(rgba(1,0,3,0.08) 1.2px, transparent 1.2px);
  background-size: 44px 44px;
  color: var(--ink);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}
a { color: var(--blue); text-decoration: none; }
a:hover { text-decoration: underline; text-underline-offset: 3px; }

/* ---------- top bar ---------- */
.topbar {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  height: var(--nav-h);
  background: rgba(252, 252, 252, 0.92);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--ink-08);
}
.topbar-inner {
  max-width: var(--maxw); margin: 0 auto; padding: 0 28px;
  height: 100%; display: flex; align-items: center; gap: 18px;
}
.brand { display: flex; align-items: center; gap: 11px; color: var(--ink); text-decoration: none !important; }
.brand svg { width: 30px; height: 30px; fill: var(--ink); transition: fill 0.25s ease; }
.brand:hover svg { fill: var(--red); }
.brand .name { font-family: var(--mono); font-size: 16px; font-weight: 700; letter-spacing: -0.02em; }
.brand .name em { font-style: normal; color: var(--red); }
.docs-mark {
  font-family: var(--mono); font-size: 16px; font-weight: 700; letter-spacing: -0.02em;
  color: var(--ink-55); text-decoration: none !important;
}
.docs-mark:hover { color: var(--ink); }
.topbar-links { margin-left: auto; display: flex; gap: 26px; }
.topbar-links a {
  font-family: var(--mono); font-size: 13px; font-weight: 500; color: var(--ink-70);
  text-decoration: none !important; position: relative; padding: 4px 0;
}
.topbar-links a::after {
  content: ''; position: absolute; left: 0; bottom: -2px; width: 0; height: 1.5px;
  background: var(--red); transition: width 0.22s ease;
}
.topbar-links a:hover { color: var(--ink); }
.topbar-links a:hover::after { width: 100%; }

/* ---------- frame ---------- */
.frame {
  max-width: var(--maxw); margin: 0 auto; padding: var(--nav-h) 28px 0;
  display: grid; grid-template-columns: var(--side-w) minmax(0, 1fr) var(--toc-w);
  gap: 48px; align-items: start;
}

/* ---------- sidebar ---------- */
.sidebar { position: sticky; top: var(--nav-h); max-height: calc(100vh - var(--nav-h)); overflow-y: auto; padding: 36px 0 48px; }
.sidebar-toggle { display: none; }
.nav-section { margin-bottom: 26px; }
.nav-title {
  font-family: var(--mono); font-size: 11px; font-weight: 700; letter-spacing: 0.12em;
  text-transform: uppercase; color: var(--ink-55); margin-bottom: 8px;
  display: flex; align-items: center; gap: 10px;
}
.nav-title::before { content: ''; width: 16px; height: 1px; background: var(--red); flex: none; }
.nav-section ul { list-style: none; border-left: 1px solid var(--ink-12); }
.nav-section li a {
  display: block; padding: 5px 0 5px 14px; margin-left: -1px;
  font-family: var(--mono); font-size: 12.5px; color: var(--ink-70);
  border-left: 1px solid transparent; text-decoration: none !important;
}
.nav-section li a:hover { color: var(--ink); border-left-color: var(--ink-25); }
.nav-section li.current a { color: var(--red); border-left-color: var(--red); font-weight: 600; }

/* ---------- main ---------- */
main { min-width: 0; padding-bottom: 48px; }
header.page { padding: 44px 0 28px; border-bottom: 1px solid var(--ink-08); margin-bottom: 28px; }
.kicker {
  font-family: var(--mono); font-size: 12px; font-weight: 600; letter-spacing: 0.14em;
  text-transform: uppercase; color: var(--ink-55); display: flex; align-items: center; gap: 12px;
}
.kicker::before { content: ''; width: 24px; height: 1px; background: var(--red); flex: none; }
header.page h1 {
  font-family: var(--mono); font-size: clamp(26px, 3.2vw, 36px); font-weight: 700;
  letter-spacing: -0.03em; line-height: 1.15; margin: 14px 0 12px;
}
header.page p.lede { max-width: 640px; font-size: 15.5px; color: var(--ink-70); }
header.page p.lede:empty { display: none; }

/* ---------- prose ---------- */
.prose { max-width: 720px; }
.prose > * + * { margin-top: 16px; }
.prose h2 {
  font-family: var(--mono); font-size: 20px; font-weight: 700; letter-spacing: -0.02em;
  margin-top: 44px; padding-top: 18px; border-top: 1px solid var(--ink-08);
}
.prose > h2:first-child { border-top: 0; padding-top: 0; margin-top: 0; }
.prose h3 { font-family: var(--mono); font-size: 15.5px; font-weight: 700; letter-spacing: -0.01em; margin-top: 30px; }
.prose h4 { font-family: var(--mono); font-size: 13px; font-weight: 700; letter-spacing: 0.04em; text-transform: uppercase; color: var(--ink-70); margin-top: 24px; }
.prose h2 .headerlink, .prose h3 .headerlink, .prose h4 .headerlink {
  color: var(--ink-25); margin-left: 8px; font-weight: 400; text-decoration: none; opacity: 0;
}
.prose h2:hover .headerlink, .prose h3:hover .headerlink, .prose h4:hover .headerlink { opacity: 1; }
.prose p { color: var(--ink); }
.prose strong { font-weight: 600; }
.prose ul, .prose ol { padding-left: 22px; }
.prose li + li { margin-top: 6px; }
.prose li > p + p { margin-top: 6px; }
.prose hr { border: 0; border-top: 1px solid var(--ink-08); margin: 32px 0; }
.prose blockquote {
  border-left: 3px solid var(--ink-12); padding: 2px 0 2px 18px; color: var(--ink-70);
}
.prose code {
  font-family: var(--mono); font-size: 12.5px; background: var(--ink-04);
  border: 1px solid var(--ink-08); padding: 1px 6px; white-space: nowrap;
}
.prose a code { color: inherit; }
.prose dl dt { font-family: var(--mono); font-size: 13px; font-weight: 600; margin-top: 12px; }
.prose dl dd { margin-left: 0; color: var(--ink-70); }
.prose img { max-width: 100%; border: 1px solid var(--ink-12); }

/* tables */
.prose table { border-collapse: collapse; width: 100%; font-size: 13.5px; border: 1px solid var(--ink-12); background: var(--bg); }
.prose th, .prose td { text-align: left; vertical-align: top; padding: 9px 12px; border-bottom: 1px solid var(--ink-08); }
.prose th {
  font-family: var(--mono); font-size: 11px; font-weight: 700; letter-spacing: 0.1em;
  text-transform: uppercase; color: var(--ink-55); background: var(--ink-04);
}
.prose tr:last-child td { border-bottom: none; }
.prose td code { white-space: normal; }

/* code panes */
.code { border: 1px solid var(--ink); background: var(--code-bg); color: var(--code-fg); margin: 18px 0; }
.code .bar {
  display: flex; align-items: center; gap: 8px; padding: 8px 14px;
  border-bottom: 1px solid rgba(252,252,252,0.14);
  font-family: var(--mono); font-size: 10.5px; letter-spacing: 0.1em; text-transform: uppercase;
  color: rgba(232,232,230,0.45);
}
.code .bar .d { width: 8px; height: 8px; border-radius: 50%; border: 1px solid rgba(252,252,252,0.25); }
.code .bar .d.r { background: var(--red); border-color: var(--red); }
.code .bar .lang { margin-left: 6px; }
.code pre { font-family: var(--mono); font-size: 12.5px; line-height: 1.75; padding: 14px 18px 18px; white-space: pre; overflow-x: auto; }
.code code { font-family: inherit; background: none; border: 0; padding: 0; font-size: inherit; white-space: pre; }
/* TERSL token colours (dark pane): header marks and query marks red, directive
   tails and references blue, strings dim, comments dimmer, identifier keys white */
.code .h { color: #FF6B57; font-weight: 700; }
.code .q { color: #FF6B57; font-weight: 700; }
.code .t { color: #7FB8D9; }
.code .rf { color: #7FB8D9; }
.code .k { color: #FCFCFC; }
.code .s { color: rgba(232,232,230,0.72); }
.code .c { color: rgba(232,232,230,0.40); }

/* callouts (markdown admonitions) */
.admonition {
  border: 1px solid var(--ink-12); border-left: 3px solid var(--red); background: var(--bg);
  padding: 12px 18px 14px; font-size: 13.5px; color: var(--ink-70);
}
.admonition.note, .admonition.info, .admonition.tip { border-left-color: var(--blue); }
.admonition .admonition-title {
  font-family: var(--mono); font-size: 11px; font-weight: 700; letter-spacing: 0.1em;
  text-transform: uppercase; color: var(--ink); margin-bottom: 6px;
}
.admonition p + p { margin-top: 8px; }
.admonition code { background: var(--ink-04); }

/* status chips */
.prose .chip {
  display: inline-block; font-family: var(--mono); font-size: 10.5px; font-weight: 600;
  letter-spacing: 0.1em; text-transform: uppercase; padding: 2px 8px; border: 1px solid var(--ink-12);
  color: var(--ink-70); vertical-align: middle;
}
.prose .chip.red { background: var(--red); border-color: var(--red); color: #FCFCFC; }
.prose .chip.blue { background: var(--blue); border-color: var(--blue); color: #FCFCFC; }

/* card grid on landing pages */
.cards { display: grid; grid-template-columns: repeat(2, 1fr); border: 1px solid var(--ink-12); background: var(--bg); margin-top: 20px; }
.cards > a, .cards > div {
  padding: 22px 24px 24px; border-right: 1px solid var(--ink-08); border-bottom: 1px solid var(--ink-08);
  color: var(--ink); text-decoration: none !important;
}
.cards > *:nth-child(2n) { border-right: none; }
.cards > *:nth-last-child(-n+2) { border-bottom: none; }
.cards > a:hover { background: var(--ink-04); }
.cards h3 { font-family: var(--mono); font-size: 14.5px; font-weight: 700; letter-spacing: -0.01em; margin: 0 0 6px; }
.cards p { font-size: 13.5px; color: var(--ink-70); margin: 0; }

/* previous / next */
.prevnext { display: flex; justify-content: space-between; gap: 16px; margin-top: 56px; border-top: 1px solid var(--ink-08); padding-top: 20px; max-width: 720px; }
.prevnext a { font-family: var(--mono); font-size: 13px; font-weight: 600; color: var(--ink); text-decoration: none !important; display: flex; flex-direction: column; gap: 2px; }
.prevnext a span { font-size: 10.5px; font-weight: 600; letter-spacing: 0.12em; text-transform: uppercase; color: var(--ink-55); }
.prevnext a:hover { color: var(--red); }
.prevnext .next { margin-left: auto; text-align: right; }

/* ---------- right-hand contents ---------- */
.toc { position: sticky; top: calc(var(--nav-h) + 44px); padding-top: 0; font-size: 12.5px; }
.toc-title { font-family: var(--mono); font-size: 11px; font-weight: 700; letter-spacing: 0.12em; text-transform: uppercase; color: var(--ink-55); margin-bottom: 8px; }
.toc ul { list-style: none; border-left: 1px solid var(--ink-12); }
.toc li a { display: block; padding: 4px 0 4px 12px; color: var(--ink-70); font-family: var(--mono); font-size: 12px; text-decoration: none !important; }
.toc li a:hover { color: var(--ink); }

/* ---------- footer ---------- */
footer {
  border-top: 1px solid var(--ink-08); margin-top: 48px; padding: 24px 0 0;
  font-family: var(--mono); font-size: 12px; color: var(--ink-55); max-width: 720px;
}
footer a { color: var(--ink); border-bottom: 1px solid var(--red); text-decoration: none !important; }
footer a:hover { color: var(--red); }

/* ---------- responsive ---------- */
@media (max-width: 1100px) {
  .frame { grid-template-columns: var(--side-w) minmax(0, 1fr); }
  .toc { display: none; }
}
@media (max-width: 900px) {
  .frame { grid-template-columns: 1fr; gap: 0; padding: var(--nav-h) 16px 0; }
  .sidebar { position: static; max-height: none; padding: 16px 0 0; border-bottom: 1px solid var(--ink-08); }
  .sidebar-toggle {
    display: block; cursor: pointer; font-family: var(--mono); font-size: 12px; font-weight: 700;
    letter-spacing: 0.12em; text-transform: uppercase; color: var(--ink-70); padding: 8px 0 12px;
  }
  .sidebar-inner { padding-bottom: 8px; }
  .topbar-links { gap: 16px; }
  .docs-mark { display: none; }
  header.page { padding-top: 28px; }
  .cards { grid-template-columns: 1fr; }
  .cards > * { border-right: none !important; border-bottom: 1px solid var(--ink-08) !important; }
  .cards > *:last-child { border-bottom: none !important; }
  .prose table { display: block; overflow-x: auto; }
}