:root { color-scheme: light dark; }
* { box-sizing: border-box; }
body {
  margin: 0 auto; padding: 28px 20px 72px; max-width: 720px;
  font-family: -apple-system, BlinkMacSystemFont, "Hiragino Sans", "Noto Sans JP", sans-serif;
  line-height: 1.85; color: #1c1c1e; background: #fff;
  -webkit-text-size-adjust: 100%;
}
@media (prefers-color-scheme: dark) {
  body { color: #ececee; background: #0d0d0f; }
  a { color: #ff9040; }
  hr { border-color: #2a2a2e; }
  .meta, footer { color: #9a9aa0; }
}
h1 { font-size: 1.5rem; letter-spacing: .02em; margin: 0 0 4px; }
h2 { font-size: 1.05rem; margin: 32px 0 8px; padding-left: 10px; border-left: 3px solid #FF6B00; }
p, li { font-size: .95rem; }
ul, ol { padding-left: 1.3em; }
a { color: #d75a00; }
.meta { font-size: .8rem; color: #6b6b70; margin: 0 0 24px; }
hr { border: 0; border-top: 1px solid #e5e5ea; margin: 36px 0 20px; }
footer { font-size: .8rem; color: #6b6b70; }
.lang { font-size: .85rem; margin-bottom: 20px; }
.card { border: 1px solid #e5e5ea; border-radius: 12px; padding: 14px 16px; margin: 16px 0; }
@media (prefers-color-scheme: dark) { .card { border-color: #2a2a2e; } }