:root {
  --c-bg: #fff;
  --c-bg-muted: #f7f7f8;
  --c-bg-code: #f4f4f5;
  --c-fg: #0e0e10;
  --c-fg-muted: #4a4a52;
  --c-fg-faint: #7a7a82;
  --c-border: #e7e7ea;
  --c-accent: #1d4ed8;
  --c-accent-bg: #eef2ff;
  --c-accent-fg: #1e3a8a;
  --c-rule: #d4d4d8;
  --max-width: 720px;
  --max-doc: 1100px;
  --font-body: -apple-system, BlinkMacSystemFont, "Segoe UI", "Helvetica Neue", system-ui, sans-serif;
  --font-mono: ui-monospace, "SF Mono", "JetBrains Mono", Menlo, Consolas, monospace;
}
@media (prefers-color-scheme: dark) {
  :root {
    --c-bg: #0c0c0e;
    --c-bg-muted: #131316;
    --c-bg-code: #1a1a1d;
    --c-fg: #ececef;
    --c-fg-muted: #a8a8b0;
    --c-fg-faint: #6e6e76;
    --c-border: #28282d;
    --c-accent: #7aa7ff;
    --c-accent-bg: #1a2540;
    --c-accent-fg: #b8d0ff;
    --c-rule: #313137;
  }
}
* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  background: var(--c-bg);
  color: var(--c-fg);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.62;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}
a { color: var(--c-accent); text-decoration: none; }
a:hover { text-decoration: underline; text-underline-offset: 2px; }
.muted { color: var(--c-fg-muted); }

/* ─── header ─── */
.site-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 18px 28px;
  border-bottom: 1px solid var(--c-border);
  position: sticky;
  top: 0;
  background: color-mix(in srgb, var(--c-bg) 90%, transparent);
  backdrop-filter: blur(8px);
  z-index: 50;
}
.brand { display: flex; align-items: center; gap: 12px; color: var(--c-fg); }
.brand:hover { text-decoration: none; }
.brand-mark {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 18px;
  letter-spacing: 0.04em;
  color: var(--c-accent);
}
.brand-tag {
  color: var(--c-fg-muted);
  font-size: 14px;
  letter-spacing: -0.005em;
}
.top-nav { display: flex; gap: 22px; }
.top-nav a {
  color: var(--c-fg);
  font-size: 14.5px;
  letter-spacing: -0.005em;
}
.top-nav a:hover { color: var(--c-accent); text-decoration: none; }

/* ─── hero ─── */
.hero {
  border-bottom: 1px solid var(--c-border);
  background:
    radial-gradient(ellipse 80% 50% at 50% 0%, color-mix(in srgb, var(--c-accent) 8%, transparent), transparent 70%),
    var(--c-bg);
  padding: 96px 28px 80px;
  text-align: center;
}
.hero-inner { max-width: 760px; margin: 0 auto; }
.hero-eyebrow {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--c-accent);
  background: var(--c-accent-bg);
  border: 1px solid color-mix(in srgb, var(--c-accent) 25%, transparent);
  border-radius: 999px;
  padding: 6px 14px;
  margin-bottom: 28px;
}
.hero-title {
  font-size: clamp(80px, 14vw, 180px);
  line-height: 0.92;
  margin: 0 0 28px;
  font-weight: 800;
  letter-spacing: -0.04em;
}
.hero-4 { color: var(--c-accent); }
.hero-a { color: var(--c-fg); }
.hero-tag {
  font-size: clamp(20px, 2.4vw, 26px);
  line-height: 1.4;
  font-weight: 500;
  margin: 0 auto 18px;
  max-width: 640px;
  color: var(--c-fg);
}
.hero-sub {
  font-size: 17px;
  line-height: 1.65;
  color: var(--c-fg-muted);
  max-width: 600px;
  margin: 0 auto 36px;
}
.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  justify-content: center;
  margin-bottom: 32px;
}
.btn {
  display: inline-block;
  padding: 11px 20px;
  border: 1px solid var(--c-border);
  border-radius: 8px;
  background: var(--c-bg);
  color: var(--c-fg);
  font-weight: 500;
  font-size: 15px;
  letter-spacing: -0.005em;
  transition: background 0.15s, border-color 0.15s;
}
.btn:hover { text-decoration: none; background: var(--c-bg-muted); border-color: var(--c-rule); }
.btn-primary {
  background: var(--c-accent);
  color: #fff;
  border-color: var(--c-accent);
}
.btn-primary:hover { background: color-mix(in srgb, var(--c-accent) 88%, black); border-color: color-mix(in srgb, var(--c-accent) 88%, black); }
.btn-ghost { border-color: transparent; color: var(--c-accent); }
.btn-ghost:hover { background: var(--c-accent-bg); border-color: transparent; }
.hero-curl {
  display: inline-block;
  background: var(--c-bg-code);
  border: 1px solid var(--c-border);
  border-radius: 8px;
  padding: 10px 16px;
  font-family: var(--font-mono);
  font-size: 14px;
  color: var(--c-fg-muted);
  margin: 0 auto;
}
.hero-curl code { background: none; padding: 0; }

/* ─── prose / markdown ─── */
.prose {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 56px 28px 80px;
  font-size: 16.5px;
}
.container { max-width: var(--max-width); }
.prose h1, .prose h2, .prose h3, .prose h4 {
  letter-spacing: -0.018em;
  line-height: 1.25;
  margin-top: 2.4em;
  margin-bottom: 0.6em;
  font-weight: 700;
}
.prose h1 { font-size: 2em; margin-top: 0; }
.prose h2 { font-size: 1.45em; padding-top: 0.4em; border-top: 1px solid var(--c-border); margin-top: 2.6em; padding-top: 1.6em; }
.prose h3 { font-size: 1.18em; }
.prose h4 { font-size: 1em; color: var(--c-fg-muted); }
.prose p { margin: 1em 0; }
.prose ul, .prose ol { padding-left: 1.4em; margin: 1em 0; }
.prose li { margin: 0.4em 0; }
.prose blockquote {
  border-left: 3px solid var(--c-accent);
  background: var(--c-accent-bg);
  padding: 12px 18px;
  margin: 1.4em 0;
  border-radius: 0 6px 6px 0;
  color: var(--c-accent-fg);
}
.prose blockquote p:first-child { margin-top: 0; }
.prose blockquote p:last-child { margin-bottom: 0; }
.prose code {
  font-family: var(--font-mono);
  font-size: 0.92em;
  background: var(--c-bg-code);
  padding: 1px 6px;
  border-radius: 4px;
  border: 1px solid var(--c-border);
}
.prose pre {
  background: var(--c-bg-code);
  border: 1px solid var(--c-border);
  border-radius: 8px;
  padding: 16px 18px;
  overflow-x: auto;
  margin: 1.4em 0;
  font-size: 14px;
  line-height: 1.55;
}
.prose pre code { background: none; border: none; padding: 0; font-size: 1em; }
.prose hr { border: none; border-top: 1px solid var(--c-border); margin: 2.4em 0; }
.prose table {
  width: 100%;
  border-collapse: collapse;
  margin: 1.4em 0;
  font-size: 0.95em;
}
.prose th, .prose td {
  text-align: left;
  padding: 10px 14px;
  border-bottom: 1px solid var(--c-border);
}
.prose th {
  background: var(--c-bg-muted);
  font-weight: 600;
  border-bottom: 2px solid var(--c-rule);
}
.prose tr:hover td { background: color-mix(in srgb, var(--c-bg-muted) 70%, transparent); }
.prose img { max-width: 100%; }
.prose del { color: var(--c-fg-faint); }

/* ─── doc layout ─── */
.layout-doc .doc-shell {
  display: grid;
  grid-template-columns: 240px minmax(0, 1fr);
  gap: 44px;
  max-width: var(--max-doc);
  margin: 0 auto;
  padding: 36px 28px 60px;
}
.sidebar {
  position: sticky;
  top: 88px;
  align-self: start;
  font-size: 14.5px;
  max-height: calc(100vh - 100px);
  overflow-y: auto;
}
.nav-home { margin-bottom: 24px; }
.nav-home-link {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--c-fg-muted);
}
.nav-home-link:hover { color: var(--c-accent); text-decoration: none; }
.nav-section { margin-bottom: 22px; }
.nav-section h4 {
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--c-fg-faint);
  font-weight: 600;
  margin: 0 0 10px;
}
.nav-section ul { list-style: none; padding: 0; margin: 0; }
.nav-section li { margin: 4px 0; }
.nav-section a {
  display: block;
  padding: 4px 10px;
  border-radius: 5px;
  color: var(--c-fg);
  border-left: 2px solid transparent;
}
.nav-section a:hover { background: var(--c-bg-muted); text-decoration: none; }
.nav-section li[aria-current="page"] a {
  color: var(--c-accent);
  border-left-color: var(--c-accent);
  background: var(--c-accent-bg);
  font-weight: 500;
}
.doc-main { min-width: 0; }
.breadcrumb {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--c-fg-muted);
  margin-bottom: 24px;
}
.breadcrumb a { color: var(--c-fg-muted); }
.breadcrumb a:hover { color: var(--c-accent); }
.breadcrumb [aria-current="page"] { color: var(--c-fg); }
.doc-head { margin-bottom: 28px; padding-bottom: 24px; border-bottom: 1px solid var(--c-border); }
.doc-head h1 { font-size: 2em; margin: 0 0 10px; letter-spacing: -0.02em; line-height: 1.18; }
.doc-summary { color: var(--c-fg-muted); font-size: 17px; margin: 0; }
.doc-main .prose { max-width: none; padding: 0; }

/* ─── footer ─── */
.site-footer {
  border-top: 1px solid var(--c-border);
  margin-top: 80px;
  padding: 48px 28px 32px;
  background: var(--c-bg-muted);
}
.footer-row {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 40px;
  max-width: var(--max-doc);
  margin: 0 auto;
}
.footer-col h5 {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--c-fg-faint);
  font-weight: 600;
  margin: 0 0 12px;
}
.footer-col ul { list-style: none; padding: 0; margin: 0; }
.footer-col li { margin: 6px 0; font-size: 14.5px; }
.footer-col a { color: var(--c-fg); }
.footer-col a:hover { color: var(--c-accent); }
.footer-baseline {
  max-width: var(--max-doc);
  margin: 32px auto 0;
  padding-top: 24px;
  border-top: 1px solid var(--c-border);
  display: flex;
  justify-content: space-between;
  font-size: 13px;
  color: var(--c-fg-muted);
}

/* ─── responsive ─── */
@media (max-width: 880px) {
  .layout-doc .doc-shell { grid-template-columns: 1fr; gap: 24px; }
  .sidebar { position: static; max-height: none; border-bottom: 1px solid var(--c-border); padding-bottom: 24px; }
  .footer-row { grid-template-columns: 1fr; gap: 28px; }
}
@media (max-width: 540px) {
  .site-header { padding: 14px 18px; }
  .brand-tag { display: none; }
  .top-nav { gap: 14px; }
  .hero { padding: 56px 18px 48px; }
  .prose { padding: 36px 18px 60px; }
}