:root {
  --bg: #f8fafc;
  --card: #ffffff;
  --ink: #0f172a;
  --muted: #475569;
  --line: #e2e8f0;
  --accent: #4f46e5;
}
* { box-sizing: border-box; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font: 16px/1.65 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}
header, main, footer { max-width: 760px; margin: 0 auto; padding-inline: 20px; }
header { padding-block: 28px 8px; display: flex; align-items: baseline; justify-content: space-between; gap: 16px; flex-wrap: wrap; }
header a.brand { font-weight: 700; font-size: 20px; color: var(--ink); text-decoration: none; }
nav a { margin-left: 16px; color: var(--muted); text-decoration: none; font-size: 15px; }
nav a:hover, nav a[aria-current="page"] { color: var(--accent); }
main { padding-block: 8px 40px; }
.card { background: var(--card); border: 1px solid var(--line); border-radius: 14px; padding: 28px; }
h1 { font-size: 30px; line-height: 1.2; margin: 0 0 6px; }
h2 { font-size: 20px; margin: 30px 0 8px; }
p, li { color: #1e293b; }
.muted { color: var(--muted); font-size: 14px; }
a { color: var(--accent); }
ul { padding-left: 22px; }
li { margin: 4px 0; }
code { background: #f1f5f9; border-radius: 6px; padding: 1px 6px; font-size: 14px; }
.links { display: flex; gap: 12px; flex-wrap: wrap; margin-top: 18px; }
.links a { border: 1px solid var(--line); border-radius: 10px; padding: 8px 14px; text-decoration: none; background: #fff; }
.links a:hover { border-color: var(--accent); }
footer { padding-block: 0 40px; font-size: 14px; color: var(--muted); }
footer a { color: var(--muted); }