:root {
  color-scheme: light dark;
  --bg: #f7f8fb;
  --card: #ffffff;
  --text: #1f2937;
  --muted: #6b7280;
  --accent: #2563eb;
  --border: #e5e7eb;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0f172a;
    --card: #111827;
    --text: #f3f4f6;
    --muted: #9ca3af;
    --accent: #60a5fa;
    --border: #374151;
  }
}
* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.65;
}
.container {
  max-width: 860px;
  margin: 0 auto;
  padding: 32px 20px 64px;
}
nav {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-bottom: 28px;
}
nav a, a { color: var(--accent); text-decoration: none; }
nav a:hover, a:hover { text-decoration: underline; }
.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 28px;
  box-shadow: 0 8px 24px rgba(0,0,0,.05);
}
h1, h2 { line-height: 1.25; }
h1 { margin-top: 0; }
small, .muted { color: var(--muted); }
footer {
  margin-top: 28px;
  color: var(--muted);
  font-size: 14px;
}
code {
  background: rgba(127,127,127,.12);
  border-radius: 6px;
  padding: 2px 6px;
}
ul { padding-left: 22px; }