:root {
  --bg: #ffffff;
  --text: #1c2230;
  --muted: #5d6677;
  --link: #1a5fd1;
  --line: #e3e7ee;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0b0e14;
    --text: #e8ecf3;
    --muted: #8b95a8;
    --link: #6fb0ff;
    --line: #262f42;
  }
}
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 16px/1.6 "Segoe UI", system-ui, -apple-system, Roboto, sans-serif;
}
main {
  max-width: 760px;
  margin: 0 auto;
  padding: 32px 16px 64px;
}
h1 { font-size: 2rem; margin: 0.4em 0 0.2em; }
h2 { font-size: 1.2rem; margin-top: 2em; padding-top: 1em; border-top: 1px solid var(--line); }
a { color: var(--link); }
.muted, .nav { color: var(--muted); font-size: 0.9rem; }
.lead { font-size: 1.15rem; }
li { margin: 0.3em 0; }