:root {
  --bg: #ffffff;
  --fg: #1f2328;
  --muted: #59636e;
  --rule: #d1d9e0;
  --link: #0969da;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0d1117;
    --fg: #e6edf3;
    --muted: #9198a1;
    --rule: #3d444d;
    --link: #4493f8;
  }
}
* { box-sizing: border-box; }
body {
  margin: 0 auto;
  padding: 3rem 1.25rem 5rem;
  max-width: 44rem;
  background: var(--bg);
  color: var(--fg);
  font: 16px/1.65 -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif;
}
h1 { font-size: 1.75rem; line-height: 1.25; margin: 0 0 .35rem; }
h2 { font-size: 1.15rem; margin: 2.25rem 0 .6rem; }
p, li { color: var(--fg); }
ul { padding-left: 1.25rem; }
li { margin: .3rem 0; }
a { color: var(--link); }
.sub { color: var(--muted); margin: 0 0 2rem; }
nav { border-top: 1px solid var(--rule); margin-top: 3rem; padding-top: 1rem; font-size: .9rem; }
nav a { margin-right: 1rem; }
footer { color: var(--muted); font-size: .85rem; margin-top: 1rem; }