:root {
  --bg: #ffffff;
  --surface: #f8fafc;
  --surface-2: #eef6ff;
  --text: #172033;
  --muted: #64748b;
  --border: #d9e2ec;
  --accent: #1565c0;
  --accent-2: #0f766e;
  --warning: #b45309;
  --code-bg: #0f172a;
  --code-text: #e5edf7;
  --shadow: 0 18px 50px rgba(15, 23, 42, .08);
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--text);
  background: var(--bg);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Arial, sans-serif;
  line-height: 1.65;
}
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }
.skip { position: absolute; left: -999px; top: 0; background: #fff; padding: .7rem; z-index: 10; }
.skip:focus { left: .5rem; }
.topbar {
  position: sticky; top: 0; z-index: 20;
  min-height: 64px; display: flex; align-items: center; justify-content: space-between; gap: 1rem;
  padding: .75rem 1.25rem; background: rgba(255,255,255,.95); border-bottom: 1px solid var(--border);
  backdrop-filter: blur(10px);
}
.brand { display: inline-flex; align-items: center; gap: .7rem; color: var(--text); font-weight: 800; }
.brand img { width: 36px; height: 36px; object-fit: contain; }
.toplinks { display: flex; gap: 1rem; font-weight: 600; }
.menu-toggle { display: none; border: 1px solid var(--border); background: white; color: var(--text); border-radius: 6px; padding: .45rem .7rem; }
.shell { display: grid; grid-template-columns: 292px minmax(0, 1fr); align-items: start; }
.sidebar {
  position: sticky; top: 64px; height: calc(100vh - 64px); overflow: auto;
  padding: 1rem; border-right: 1px solid var(--border); background: var(--surface);
}
.sidebar nav { display: grid; gap: .15rem; margin-top: 1rem; }
.sidebar nav a { color: #334155; padding: .52rem .7rem; border-radius: 6px; font-weight: 600; }
.sidebar nav a.active, .sidebar nav a:hover { background: #e7f0fb; color: var(--accent); text-decoration: none; }
.search-label { display: block; color: var(--muted); font-size: .85rem; font-weight: 700; margin-bottom: .35rem; }
.search { width: 100%; border: 1px solid var(--border); border-radius: 6px; padding: .65rem .75rem; font: inherit; background: #fff; }
.search-results { margin-top: .5rem; display: grid; gap: .25rem; }
.search-results a { display: block; background: #fff; border: 1px solid var(--border); border-radius: 6px; padding: .45rem .55rem; color: var(--text); font-size: .9rem; }
.content { max-width: 1120px; width: 100%; padding: 2rem clamp(1.1rem, 4vw, 4rem) 4rem; }
h1, h2, h3 { line-height: 1.2; letter-spacing: 0; }
h1 { font-size: clamp(2rem, 4vw, 3.45rem); margin: .2rem 0 1rem; color: #0f172a; }
h2 { font-size: 1.65rem; margin-top: 2.4rem; padding-top: .3rem; }
h3 { font-size: 1.08rem; margin-top: 1.4rem; }
.lead { font-size: 1.2rem; color: #3b4758; max-width: 920px; }
.eyebrow { color: var(--accent-2); text-transform: uppercase; letter-spacing: .08em; font-weight: 800; margin: 0 0 .6rem; }
.hero { padding: 1rem 0 1.5rem; }
.logo { max-width: 300px; width: min(70vw, 300px); height: auto; display: block; margin-bottom: 1rem; }
.actions { display: flex; flex-wrap: wrap; gap: .7rem; margin-top: 1.25rem; }
.button { display: inline-flex; align-items: center; justify-content: center; border: 1px solid var(--border); border-radius: 6px; min-height: 42px; padding: .55rem .9rem; color: var(--text); font-weight: 800; background: #fff; }
.button.primary { background: var(--accent); color: #fff; border-color: var(--accent); }
.feature-grid, .card-grid, .api-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(230px, 1fr)); gap: .8rem; margin: 1rem 0; }
.feature-grid div, .card, .api-card { border: 1px solid var(--border); border-radius: 8px; background: #fff; padding: 1rem; box-shadow: 0 8px 24px rgba(15, 23, 42, .04); }
.feature-grid div { font-weight: 700; }
.card h3, .api-card h3 { margin-top: 0; }
.muted { color: var(--muted); }
.callout { border-left: 4px solid var(--accent); background: var(--surface-2); padding: .9rem 1rem; border-radius: 6px; margin: 1.25rem 0; }
.callout.warning { border-left-color: var(--warning); background: #fff7ed; }
.callout p { margin: .3rem 0 0; }
.notebook-reference { margin-top: 3rem; padding-top: 1.25rem; border-top: 2px solid var(--border); }
.notebook-reference h2:first-child { margin-top: 0; }
.notebook-reference h3 { margin-top: 2rem; color: #0f172a; }
.notebook-reference h4 { margin-top: 1.5rem; color: #233044; }
.notebook-code { margin: 1rem 0 1.5rem; }
.notebook-code figcaption { color: var(--muted); font-weight: 800; font-size: .85rem; margin-bottom: .35rem; }
pre { position: relative; overflow: auto; background: var(--code-bg); color: var(--code-text); border-radius: 8px; padding: 1rem; box-shadow: var(--shadow); }
code { font-family: "SFMono-Regular", Consolas, "Liberation Mono", monospace; font-size: .92em; }
:not(pre) > code { background: #edf2f7; color: #0f172a; padding: .1rem .3rem; border-radius: 4px; }
pre code { display: block; white-space: pre; }
.copy { position: absolute; right: .55rem; top: .55rem; border: 1px solid rgba(255,255,255,.25); background: rgba(255,255,255,.08); color: #fff; border-radius: 5px; padding: .25rem .5rem; cursor: pointer; }
table { width: 100%; border-collapse: collapse; margin: 1rem 0 1.5rem; font-size: .95rem; }
th, td { border: 1px solid var(--border); padding: .65rem .75rem; vertical-align: top; }
th { background: var(--surface); text-align: left; color: #0f172a; }
details { border: 1px solid var(--border); border-radius: 8px; padding: .8rem 1rem; margin: .7rem 0; background: #fff; }
summary { cursor: pointer; font-weight: 800; color: #0f172a; }
.footer { border-top: 1px solid var(--border); display: flex; flex-wrap: wrap; gap: 1rem; justify-content: center; padding: 1.5rem; color: var(--muted); background: var(--surface); }
@media (max-width: 860px) {
  .toplinks { display: none; }
  .menu-toggle { display: inline-flex; }
  .shell { grid-template-columns: 1fr; }
  .sidebar { display: none; position: fixed; top: 64px; left: 0; right: 0; height: calc(100vh - 64px); z-index: 30; border-right: 0; border-bottom: 1px solid var(--border); }
  body.nav-open .sidebar { display: block; }
  .content { padding-top: 1.25rem; }
  table { display: block; overflow-x: auto; }
}