:root {
  color-scheme: light dark;
  --fg: #1d1d1f;
  --bg: #ffffff;
  --muted: #6e6e73;
  --accent: #0a66c2;
  --rule: #e5e5ea;
}
@media (prefers-color-scheme: dark) {
  :root {
    --fg: #f5f5f7;
    --bg: #1c1c1e;
    --muted: #98989d;
    --accent: #6cb0f5;
    --rule: #3a3a3c;
  }
}
* { box-sizing: border-box; }
body {
  margin: 0;
  font: 17px/1.55 -apple-system, BlinkMacSystemFont, "SF Pro Text", "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  color: var(--fg);
  background: var(--bg);
  -webkit-text-size-adjust: 100%;
}
header, main, footer {
  max-width: 42rem;
  margin: 0 auto;
  padding: 0 1.25rem;
}
header {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  padding-top: 1.5rem;
}
header .brand {
  font-weight: 700;
  font-size: 1.1rem;
  color: inherit;
  text-decoration: none;
}
header nav a {
  color: var(--muted);
  text-decoration: none;
  margin-left: 1.25rem;
}
a { color: var(--accent); }
a:hover, header nav a:hover { text-decoration: underline; }
h1 {
  font-size: 2rem;
  line-height: 1.2;
  letter-spacing: -0.01em;
  margin: 2.5rem 0 0.5rem;
}
h2 { font-size: 1.3rem; margin: 2.25rem 0 0.5rem; }
h3 { font-size: 1.05rem; margin: 1.5rem 0 0.25rem; }
p, li { margin: 0.5rem 0; }
ul { padding-left: 1.25rem; }
.lead { color: var(--muted); font-size: 1.1rem; }
.meta { color: var(--muted); font-size: 0.95rem; margin-top: 0; }
footer {
  border-top: 1px solid var(--rule);
  margin-top: 3rem;
  padding-top: 1rem;
  padding-bottom: 3rem;
  color: var(--muted);
  font-size: 0.95rem;
}
footer a { color: inherit; }