:root {
  color-scheme: light dark;
  --background: #f8f9fa;
  --text: #222;
  --muted: #626b75;
  --border: #cfd5db;
  --link: #005eb8;
  --panel: #edf1f5;
}
* { box-sizing: border-box; }
body {
  font-family: Arial, sans-serif;
  max-width: 900px;
  margin: 40px auto;
  padding: 0 20px;
  line-height: 1.6;
  color: var(--text);
  background: var(--background);
}
header { border-bottom: 1px solid var(--border); padding-bottom: 20px; margin-bottom: 30px; }
h1 { margin-bottom: 5px; line-height: 1.2; }
nav { display: flex; flex-wrap: wrap; gap: 12px 24px; }
a { color: var(--link); text-decoration: none; }
a:hover { text-decoration: underline; }
a:focus-visible { outline: 2px solid var(--link); outline-offset: 4px; }
pre { overflow-x: auto; padding: 16px; background: var(--panel); border-radius: 6px; }
.notice { padding: 16px; border-left: 4px solid var(--link); background: var(--panel); }
footer { margin-top: 50px; padding-top: 20px; border-top: 1px solid var(--border); font-size: .9rem; color: var(--muted); }
@media (prefers-color-scheme: dark) {
  :root { --background: #15191d; --text: #e8edf2; --muted: #aeb8c2; --border: #39434d; --link: #7bbcff; --panel: #222a32; }
}
@media (max-width: 480px) {
  body { margin: 24px auto; padding: 0 16px; }
  h1 { font-size: 1.8rem; }
}