:root { --brand: #D6336C; --ink: #1C1C1E; --secondary: #6e6e73; --bg: #f7f7f8; --line: #e5e5ea; }
@media (prefers-color-scheme: dark) {
  :root { --brand: #FF6B9A; --ink: #F2F2F7; --secondary: #a1a1a6; --bg: #1c1c1e; --line: #3a3a3c; }
}
* { box-sizing: border-box; }
body { margin: 0; font-family: -apple-system, BlinkMacSystemFont, "Hiragino Sans", "Noto Sans JP", sans-serif; color: var(--ink); background: var(--bg); line-height: 1.8; }
main { max-width: 720px; margin: 0 auto; padding: 48px 16px 80px; }
h1 { font-size: 1.6rem; letter-spacing: -0.02em; }
h1 .app { color: var(--brand); }
h2 { font-size: 1.1rem; margin-top: 2.2em; border-left: 4px solid var(--brand); padding-left: 10px; }
h3 { font-size: 1rem; margin-bottom: 0.2em; }
p, li { font-size: 0.95rem; }
.meta { color: var(--secondary); font-size: 0.85rem; }
a { color: var(--brand); }
footer { margin-top: 4em; padding-top: 1.5em; border-top: 1px solid var(--line); color: var(--secondary); font-size: 0.85rem; }
nav { margin-bottom: 2em; font-size: 0.9rem; }