:root {
  --bg: #ffffff;
  --fg: #1d1d1f;
  --muted: #6e6e73;
  --line: #e5e5ea;
  --accent: #ff6a3d;
  --accent-ink: #ffffff;
  --link: #0066cc;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #000000;
    --fg: #f5f5f7;
    --muted: #a1a1a6;
    --line: #2c2c2e;
    --link: #4da3ff;
  }
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: -apple-system, BlinkMacSystemFont, "Helvetica Neue", "Hiragino Sans", "Hiragino Kaku Gothic ProN", Meiryo, sans-serif;
  font-size: 17px;
  line-height: 1.7;
}
.wrap { max-width: 760px; margin: 0 auto; padding: 0 20px; }
a { color: var(--link); }
.site-header { border-bottom: 1px solid var(--line); padding: 14px 0 6px; }
.site-header .wrap:first-child { display: flex; align-items: center; justify-content: space-between; }
.brand { font-weight: 700; font-size: 20px; color: var(--fg); text-decoration: none; }
.lang { font-size: 14px; }
.site-header nav { display: flex; flex-wrap: wrap; gap: 4px 16px; padding-top: 6px; font-size: 14px; }
.site-header nav a { color: var(--muted); text-decoration: none; }
.site-header nav a[aria-current="page"] { color: var(--fg); font-weight: 600; }
main { padding-top: 12px; padding-bottom: 40px; }
h1 { font-size: 30px; line-height: 1.3; margin: 24px 0 12px; }
h2 { font-size: 21px; margin: 32px 0 8px; }
h3 { font-size: 17px; margin: 22px 0 4px; }
.lead { font-size: 19px; color: var(--muted); }
.note { color: var(--muted); font-size: 15px; }
.updated { color: var(--muted); font-size: 14px; }
.button {
  display: inline-block;
  background: var(--accent);
  color: var(--accent-ink);
  padding: 10px 22px;
  border-radius: 999px;
  text-decoration: none;
  font-weight: 600;
}
.site-footer { border-top: 1px solid var(--line); color: var(--muted); font-size: 14px; padding: 12px 0 28px; }
.site-footer a { color: var(--muted); }