:root { font-family: system-ui, -apple-system, Segoe UI, Roboto, Arial, sans-serif; }
* { box-sizing: border-box; }
body { margin: 0; background: #f7f7fb; color: #222; }
.container { max-width: 900px; margin: 0 auto; padding: 1.5rem; }
header { display: flex; flex-wrap: wrap; align-items: center; gap: 0.75rem; }
nav a { margin-right: 1rem; text-decoration: none; color: #0366d6; }
nav a[aria-current="page"] { font-weight: 700; }
main { background: white; padding: 1.5rem; border-radius: 12px; box-shadow: 0 4px 24px rgba(0,0,0,0.06); margin-top: 1rem; }
code { background: #eef; padding: 0.2rem 0.4rem; border-radius: 6px; }
footer { margin-top: 1.25rem; color: #666; }