:root {
  --bg: #ffffff;
  --fg: #1a1a1a;
  --muted: #6b6b6b;
  --line: #e5e5e5;
  --accent: #2f5bea;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #111111;
    --fg: #ededed;
    --muted: #9a9a9a;
    --line: #2a2a2a;
    --accent: #7c9cff;
  }
}
* { box-sizing: border-box; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: -apple-system, BlinkMacSystemFont, "Hiragino Sans", "Noto Sans JP", sans-serif;
  line-height: 1.8;
}
.wrap { max-width: 720px; margin: 0 auto; padding: 48px 16px; }
header { display: flex; justify-content: space-between; align-items: baseline; border-bottom: 1px solid var(--line); padding-bottom: 16px; margin-bottom: 40px; }
header .logo { font-size: 24px; font-weight: 700; letter-spacing: 0.02em; color: var(--fg); text-decoration: none; }
nav a { color: var(--muted); text-decoration: none; margin-left: 16px; font-size: 14px; }
nav a:hover { color: var(--fg); }
h1 { font-size: 28px; margin: 0 0 24px; }
h2 { font-size: 18px; margin: 40px 0 8px; }
p, li { color: var(--fg); }
a { color: var(--accent); }
dl { display: grid; grid-template-columns: 8em 1fr; gap: 12px 16px; margin: 0; }
dt { color: var(--muted); }
dd { margin: 0; }
.muted { color: var(--muted); font-size: 14px; }
footer { border-top: 1px solid var(--line); margin-top: 64px; padding-top: 16px; color: var(--muted); font-size: 13px; }
@media (max-width: 480px) {
  dl { grid-template-columns: 1fr; gap: 2px; }
  dd { margin-bottom: 12px; }
}