:root {
  --bg: #fafbfc;
  --text: #2f3438;
  --sub: #6b7a88;
  --accent: #2f5e3e;
  --border: #dde1e5;
}
@media (prefers-color-scheme: dark) {
  :root { --bg: #1e1f23; --text: #e2e4e8; --sub: #9aa4ae; --accent: #8fbf6a; --border: #2f3137; }
}
* { box-sizing: border-box; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, "Helvetica Neue", Arial, "Hiragino Kaku Gothic ProN", "Hiragino Sans", Meiryo, sans-serif;
  line-height: 1.7;
}
main { max-width: 720px; margin: 0 auto; padding: 48px 16px 64px; }
header { display: flex; align-items: center; gap: 14px; margin-bottom: 8px; }
header img { width: 56px; height: 56px; }
h1 { font-size: 28px; margin: 0; }
h2 { font-size: 20px; margin: 36px 0 8px; border-bottom: 1px solid var(--border); padding-bottom: 6px; }
h3 { font-size: 16px; margin: 20px 0 4px; }
p, li { font-size: 15px; }
.tagline { color: var(--sub); margin: 0 0 24px; font-size: 16px; }
.lang { color: var(--sub); font-size: 13px; }
a { color: var(--accent); }
nav a { margin-right: 16px; }
footer { margin-top: 48px; color: var(--sub); font-size: 13px; border-top: 1px solid var(--border); padding-top: 12px; }
.langs { list-style: none; margin: 0 0 8px; padding: 0; display: flex; flex-wrap: wrap; gap: 4px 14px; }
.langs a[aria-current] { color: var(--sub); text-decoration: none; }