:root {
  --text: #1d1d1f;
  --sub: #5b5b60;
  --line: #d9dde3;
  --accent: #2f74e0;
  --bg: #ffffff;
  --card: #f5f7fa;
}
@media (prefers-color-scheme: dark) {
  :root {
    --text: #f2f2f4;
    --sub: #a6a6ad;
    --line: #3a3a3e;
    --accent: #6ea8ff;
    --bg: #161618;
    --card: #222226;
  }
}
* { box-sizing: border-box; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Hiragino Sans", "Hiragino Kaku Gothic ProN", "Noto Sans JP", sans-serif;
  line-height: 1.8;
}
main { max-width: 720px; margin: 0 auto; padding: 32px 16px 64px; }
header { display: flex; align-items: center; gap: 16px; margin-bottom: 8px; }
header img { width: 72px; height: 72px; border-radius: 16px; }
h1 { font-size: 1.6rem; margin: 0; }
h2 { font-size: 1.15rem; margin: 2em 0 0.5em; padding-bottom: 4px; border-bottom: 1px solid var(--line); }
p, li { font-size: 1rem; }
.lead { color: var(--sub); margin-top: 4px; }
.card { background: var(--card); border-radius: 12px; padding: 12px 16px; }
a { color: var(--accent); }
nav { margin: 24px 0; display: flex; gap: 16px; flex-wrap: wrap; }
footer { margin-top: 48px; color: var(--sub); font-size: 0.85rem; }