:root {
  --bg: #ffffff; --fg: #334155; --head: #0f172a; --muted: #64748b;
  --line: #e2e8f0; --accent: #6366f1; --card: #f8fafc;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0f172a; --fg: #cbd5e1; --head: #f1f5f9; --muted: #94a3b8;
    --line: #1e293b; --accent: #818cf8; --card: #1e293b;
  }
}
* { box-sizing: border-box; }
body {
  margin: 0; background: var(--bg); color: var(--fg);
  font: 16px/1.6 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
}
.wrap { max-width: 720px; margin: 0 auto; padding: 48px 24px 96px; }

nav { display: flex; gap: 20px; align-items: center; margin-bottom: 44px; font-size: 15px; }
nav .brand { font-weight: 700; color: var(--head); text-decoration: none; letter-spacing: -0.01em; }
nav a { color: var(--muted); text-decoration: none; }
nav a:hover { color: var(--accent); }
nav .spacer { flex: 1; }

h1 { font-size: 38px; line-height: 1.15; margin: 0 0 12px; color: var(--head); letter-spacing: -0.025em; }
h2 { font-size: 22px; margin: 44px 0 12px; color: var(--head); }
h3 { font-size: 17px; margin: 26px 0 8px; color: var(--head); }
p, li { margin: 0 0 12px; }
ul { padding-left: 22px; }
a { color: var(--accent); }
.lead { font-size: 19px; color: var(--muted); margin-bottom: 32px; }
.meta { font-size: 14px; color: var(--muted); }

.card {
  background: var(--card); border: 1px solid var(--line);
  border-radius: 12px; padding: 20px 22px; margin: 20px 0;
}
.grid { display: grid; gap: 14px; grid-template-columns: 1fr 1fr; margin: 28px 0; }
@media (max-width: 620px) { .grid { grid-template-columns: 1fr; } }
.grid .card { margin: 0; }
.grid h3 { margin: 0 0 6px; font-size: 16px; }
.grid p { margin: 0; font-size: 15px; color: var(--muted); }

hr { border: 0; border-top: 1px solid var(--line); margin: 52px 0; }
code { background: var(--card); padding: 1px 6px; border-radius: 5px; font-size: 14px; }
footer { margin-top: 64px; padding-top: 24px; border-top: 1px solid var(--line); font-size: 14px; color: var(--muted); }
footer a { color: var(--muted); }