:root { --max: 980px; --muted:#555; --border:#e9e9e9; --bg:#fafafa; }
    body { font-family: system-ui, -apple-system, Segoe UI, Roboto, Arial, sans-serif; line-height: 1.6; margin: 0; color:#111; }
    header, main, footer { max-width: var(--max); margin: 0 auto; padding: 22px 18px; }
    header { padding-top: 30px; }
    h1 { margin: 0 0 8px; font-size: 2rem; }
    h2 { margin-top: 28px; }
    h3 { margin-top: 18px; }
    p { margin: 0.6rem 0; }
    ul { padding-left: 1.1rem; }
    .meta { color: var(--muted); }
    .box { background: var(--bg); border: 1px solid var(--border); padding: 12px 14px; border-radius: 12px; }
    nav { border: 1px solid var(--border); border-radius: 12px; padding: 12px 14px; margin: 14px 0 0; }
    nav ol { margin: 0; padding-left: 1.2rem; }
    hr { border: 0; border-top: 1px solid var(--border); margin: 22px 0; }
    a { color: inherit; }
    code { background: #f3f3f3; padding: 2px 5px; border-radius: 4px; }