:root {
  --bg: #ffffff;
  --text: #1c1c1c;
  --muted: #5f6368;
  --brand: #1d4f91;
  --card: #f4f6f9;
  --border: #e3e3e3;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #121417;
    --text: #e8eaed;
    --muted: #9aa0a6;
    --brand: #8ab4f8;
    --card: #1c1f24;
    --border: #2d3138;
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 16px/1.6 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}

header, main, footer {
  max-width: 760px;
  margin: 0 auto;
  padding: 0 16px;
}

header {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 20px;
  align-items: center;
  justify-content: space-between;
  padding-top: 20px;
  padding-bottom: 20px;
  border-bottom: 1px solid var(--border);
}

header .logo {
  font-weight: 700;
  color: var(--brand);
  text-decoration: none;
}

nav a {
  color: var(--muted);
  text-decoration: none;
  margin-left: 16px;
}

nav a:first-child { margin-left: 0; }
nav a:hover, nav a[aria-current="page"] { color: var(--brand); }

main { padding-top: 24px; padding-bottom: 48px; }

h1 { font-size: 28px; line-height: 1.25; color: var(--brand); margin: 0 0 8px; }
h2 { font-size: 19px; margin: 28px 0 6px; }

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

.muted { color: var(--muted); }

.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 16px 18px;
  margin: 20px 0;
}

ol, ul { padding-left: 22px; }

footer {
  padding-top: 16px;
  padding-bottom: 32px;
  border-top: 1px solid var(--border);
  color: var(--muted);
  font-size: 14px;
}