:root {
  --bg: #ffffff;
  --text: #1c1c1e;
  --muted: #6e6e73;
  --accent: #5856d6;
  --line: #e5e5ea;
  color-scheme: light dark;
}
@media (prefers-color-scheme: dark) {
  :root { --bg: #000000; --text: #f2f2f7; --muted: #98989d; --accent: #7d7aff; --line: #38383a; }
}
* { box-sizing: border-box; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 16px/1.7 -apple-system, BlinkMacSystemFont, "Apple SD Gothic Neo", "Hiragino Sans", "PingFang SC", sans-serif;
}
main { max-width: 720px; margin: 0 auto; padding: 32px 16px 64px; }
nav { font-size: 14px; color: var(--muted); margin-bottom: 24px; }
a { color: var(--accent); }
h1 { font-size: 28px; line-height: 1.3; margin: 0 0 4px; }
h2 { font-size: 18px; margin: 32px 0 8px; }
.meta { color: var(--muted); margin-top: 0; }
ul { padding-left: 20px; }
li { margin: 6px 0; }
hr { border: 0; border-top: 1px solid var(--line); margin: 56px 0; }