:root {
  --bg: #ffffff;
  --fg: #1a1a1a;
  --muted: #5c6370;
  --accent: #0b6e4f;
  --accent-light: #e6f2ee;
  --border: #e2e2e2;
  --code-bg: #f6f8fa;
  --warn-bg: #fff8e6;
  --warn-border: #e6c200;
  --max-width: 960px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #14161a;
    --fg: #e4e6eb;
    --muted: #9aa1ac;
    --accent: #3ecf8e;
    --accent-light: #1b2a24;
    --border: #2c3038;
    --code-bg: #1d2025;
    --warn-bg: #2a2510;
    --warn-border: #8a7400;
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
    Helvetica, Arial, sans-serif;
  background: var(--bg);
  color: var(--fg);
  line-height: 1.6;
}

nav.topnav {
  border-bottom: 1px solid var(--border);
  padding: 0.75rem 1.5rem;
  display: flex;
  align-items: center;
  gap: 1.5rem;
  flex-wrap: wrap;
}

nav.topnav .brand {
  font-weight: 700;
  font-size: 1.1rem;
  color: var(--accent);
  text-decoration: none;
}

nav.topnav a {
  color: var(--fg);
  text-decoration: none;
  font-size: 0.95rem;
}

nav.topnav a:hover { color: var(--accent); }
nav.topnav a.active { color: var(--accent); font-weight: 600; }

main {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 2rem 1.5rem 4rem;
}

h1, h2, h3, h4 { line-height: 1.25; }

h1 { font-size: 2rem; margin-top: 0; }

h2 {
  font-size: 1.4rem;
  margin-top: 2.5rem;
  padding-bottom: 0.3rem;
  border-bottom: 1px solid var(--border);
}

h3 { font-size: 1.1rem; margin-top: 1.75rem; }

a { color: var(--accent); }

code {
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
  font-size: 0.875em;
  background: var(--code-bg);
  padding: 0.15em 0.35em;
  border-radius: 4px;
}

pre {
  background: var(--code-bg);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 1rem;
  overflow-x: auto;
  line-height: 1.45;
}

pre code {
  background: none;
  padding: 0;
  font-size: 0.85rem;
}

table {
  border-collapse: collapse;
  width: 100%;
  margin: 1rem 0;
  font-size: 0.92rem;
}

th, td {
  border: 1px solid var(--border);
  padding: 0.45rem 0.7rem;
  text-align: left;
  vertical-align: top;
}

th { background: var(--code-bg); }

.lead {
  font-size: 1.1rem;
  color: var(--muted);
  max-width: 42rem;
}

.callout {
  background: var(--accent-light);
  border-left: 4px solid var(--accent);
  border-radius: 0 8px 8px 0;
  padding: 0.75rem 1rem;
  margin: 1rem 0;
}

.callout.warn {
  background: var(--warn-bg);
  border-left-color: var(--warn-border);
}

.cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 1rem;
  margin: 1.5rem 0;
}

.card {
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 1rem 1.25rem;
}

.card h3 { margin-top: 0; }
.card p { color: var(--muted); font-size: 0.95rem; }

footer {
  border-top: 1px solid var(--border);
  color: var(--muted);
  font-size: 0.85rem;
  text-align: center;
  padding: 1.5rem;
}

.toc {
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 0.75rem 1.25rem;
  margin: 1.5rem 0;
  font-size: 0.95rem;
}

.toc ul { margin: 0.25rem 0; padding-left: 1.25rem; }