:root {
  --bg: #ffffff;
  --text: #1c1c1e;
  --hint: #636366;
  --line: #e5e5ea;
  --link: #007aff;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #17212b;
    --text: #f5f5f5;
    --hint: #a7b4c1;
    --line: #2b3a4a;
    --link: #64a8ff;
  }
}
:root[data-theme="dark"] {
  --bg: #17212b;
  --text: #f5f5f5;
  --hint: #a7b4c1;
  --line: #2b3a4a;
  --link: #64a8ff;
}
* { box-sizing: border-box; }
body { margin: 0; background: var(--bg); color: var(--text); font: 16px/1.55 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif; }
main { max-width: 720px; margin: 0 auto; padding: 24px 16px 48px; overflow-wrap: anywhere; }
h1 { font-size: 24px; line-height: 1.25; margin: 0 0 8px; }
h2 { font-size: 18px; margin: 28px 0 8px; padding-top: 16px; border-top: 1px solid var(--line); }
p, li { margin: 0 0 10px; }
ul { padding-left: 20px; }
.meta { color: var(--hint); font-size: 14px; }
a { color: var(--link); }