:root { color-scheme: light dark; }
* { box-sizing: border-box; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  max-width: 720px; margin: 0 auto; padding: 48px 22px 80px;
  line-height: 1.65; color: #1b1b26; background: #fbfbfe;
}
@media (prefers-color-scheme: dark) {
  body { color: #e8e8f0; background: #14141f; }
  a { color: #8fa6ff; }
  .card { background: #1e1e2e; border-color: #2e2e42; }
  .muted { color: #9a9ab0; }
}
h1 { font-size: 1.75rem; line-height: 1.25; margin: 0 0 .35rem; }
h2 { font-size: 1.1rem; margin: 2.25rem 0 .5rem; }
.muted { color: #6b6b80; font-size: .92rem; }
.card { background: #fff; border: 1px solid #e6e6f0; border-radius: 14px; padding: 18px 20px; margin: 18px 0; }
ul { padding-left: 1.15rem; }
li { margin: .3rem 0; }
a { color: #3d5afe; }
nav { margin-bottom: 28px; font-size: .95rem; }
nav a { margin-right: 16px; }
footer { margin-top: 56px; padding-top: 20px; border-top: 1px solid #e6e6f0; font-size: .85rem; }
@media (prefers-color-scheme: dark) { footer { border-color: #2e2e42; } }