:root {
  color-scheme: light dark;
  --ink: #16181d;
  --muted: #59616e;
  --paper: #ffffff;
  --soft: #f6f8fb;
  --line: #d8dde5;
  --accent: #0b6bcb;
  --code: #f3f5f8;
}
@media (prefers-color-scheme: dark) {
  :root {
    --ink: #e8edf5;
    --muted: #aab4c3;
    --paper: #11151b;
    --soft: #171c24;
    --line: #303946;
    --accent: #73b7ff;
    --code: #1d2430;
  }
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font: 16px/1.62 system-ui, -apple-system, Segoe UI, sans-serif;
}
a { color: var(--accent); text-underline-offset: .16em; }
a:hover { text-decoration-thickness: .12em; }
.topbar {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: .8rem max(1rem, 4vw);
  border-bottom: 1px solid var(--line);
  background: color-mix(in srgb, var(--paper) 94%, transparent);
  backdrop-filter: blur(12px);
}
.brand { color: var(--ink); font-weight: 750; letter-spacing: -.02em; text-decoration: none; }
.topnav { display: flex; flex-wrap: wrap; gap: 1rem; font-size: .94rem; }
.topnav a { color: var(--muted); text-decoration: none; }
.topnav a:hover { color: var(--accent); }
.shell {
  display: grid;
  grid-template-columns: 250px minmax(0, 1fr);
  gap: 2.4rem;
  max-width: 1500px;
  margin: 0 auto;
  padding: 2rem max(1rem, 4vw) 5rem;
}
.sidebar {
  position: sticky;
  top: 4.3rem;
  align-self: start;
  max-height: calc(100vh - 6rem);
  overflow: auto;
  padding-right: .5rem;
  border-right: 1px solid var(--line);
}
.nav-section { margin: 0 0 1.35rem; }
.nav-section h2 {
  margin: 0 0 .35rem;
  color: var(--muted);
  font-size: .72rem;
  letter-spacing: .1em;
  text-transform: uppercase;
}
.nav-section a {
  display: block;
  padding: .22rem 0;
  color: var(--muted);
  font-size: .9rem;
  line-height: 1.35;
  text-decoration: none;
}
.nav-section a:hover, .nav-section a[aria-current="page"] { color: var(--accent); }
.nav-section a[aria-current="page"] { font-weight: 650; }
.content {
  min-width: 0;
  max-width: 1000px;
  overflow-wrap: anywhere;
}
.content h1, .content h2, .content h3, .content h4 {
  line-height: 1.2;
  letter-spacing: -.02em;
  scroll-margin-top: 5rem;
}
.content h1 { margin: .1rem 0 1.2rem; font-size: clamp(2rem, 4vw, 3rem); }
.content h2 {
  margin: 2.5rem 0 .8rem;
  padding-bottom: .35rem;
  border-bottom: 1px solid var(--line);
  font-size: clamp(1.35rem, 2.4vw, 1.8rem);
}
.content h3 { margin: 1.8rem 0 .5rem; font-size: 1.2rem; }
.content p, .content li { color: var(--ink); }
.content p { margin: .75rem 0; }
.content ul, .content ol { padding-left: 1.4rem; }
.content li { margin: .28rem 0; }
.content blockquote {
  margin: 1.2rem 0;
  padding: .7rem 1rem;
  border-left: 3px solid var(--accent);
  background: var(--soft);
  color: var(--muted);
}
.content code {
  padding: .15rem .32rem;
  border-radius: 5px;
  background: var(--code);
  font-family: ui-monospace, SFMono-Regular, Consolas, monospace;
  font-size: .9em;
}
.content pre {
  overflow: auto;
  padding: 1rem;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: var(--code);
  line-height: 1.45;
}
.content pre code { padding: 0; background: transparent; }
.content table {
  display: block;
  width: 100%;
  overflow: auto;
  border-collapse: collapse;
  margin: 1.2rem 0;
}
.content th, .content td {
  padding: .5rem .7rem;
  border: 1px solid var(--line);
  text-align: left;
  vertical-align: top;
}
.content th { background: var(--soft); }
.content img { max-width: 100%; height: auto; }
.content hr { border: 0; border-top: 1px solid var(--line); margin: 2rem 0; }
.content .headerlink { margin-left: .35rem; font-size: .7em; text-decoration: none; opacity: .35; }
.content .headerlink:hover { opacity: 1; }
.diagram-canvas {
  position: relative;
  height: min(68vh, 720px);
  min-height: 340px;
  margin: 1.4rem 0;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 14px;
  background: var(--paper);
  cursor: grab;
  touch-action: none;
}
.diagram-canvas:active { cursor: grabbing; }
.diagram-canvas svg { width: 100%; height: 100%; max-width: none !important; }
.diagram-canvas .error { padding: 1rem; color: #b42318; font-family: ui-monospace, monospace; }
.footer {
  margin-top: 3rem;
  padding-top: 1rem;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: .85rem;
}
@media (max-width: 900px) {
  .shell { display: block; padding-top: 1.2rem; }
  .sidebar {
    position: static;
    max-height: none;
    margin-bottom: 1.5rem;
    padding: 0 0 1rem;
    border-right: 0;
    border-bottom: 1px solid var(--line);
  }
  .nav-section { margin-bottom: .9rem; }
  .nav-section a { display: inline-block; margin-right: .75rem; }
}
@media (max-width: 640px) {
  .diagram-canvas { height: 58vh; min-height: 280px; }
  .topnav { gap: .65rem; font-size: .85rem; }
}