:root {
  --bg: #ffffff;
  --text: #1f2328;
  --muted: #59636e;
  --accent: #1f9d55;
  --border: #d8dee4;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0d1117;
    --text: #e6edf3;
    --muted: #9198a1;
    --accent: #3fb950;
    --border: #30363d;
  }
}
* { box-sizing: border-box; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Hiragino Sans", "Hiragino Kaku Gothic ProN", "Segoe UI", sans-serif;
  line-height: 1.75;
}
main { max-width: 720px; margin: 0 auto; padding: 32px 16px 64px; }
h1 { font-size: 1.6rem; line-height: 1.4; margin: 0 0 4px; }
h2 { font-size: 1.15rem; margin: 2em 0 0.5em; padding-bottom: 4px; border-bottom: 1px solid var(--border); }
a { color: var(--accent); }
.meta { color: var(--muted); font-size: 0.9rem; margin: 0 0 24px; }
.lang { font-size: 0.9rem; margin-bottom: 24px; }
.lang a { margin-right: 12px; }
hr { border: none; border-top: 1px solid var(--border); margin: 48px 0; }
ul { padding-left: 1.4em; }
footer { color: var(--muted); font-size: 0.85rem; margin-top: 48px; }