html, body { margin: 0; padding: 0; font-family: system-ui, Arial, sans-serif; }
header { display:flex; gap: 16px; align-items:center; padding: 12px 16px; background:#0f172a; color:#fff; }
header a { color:#93c5fd; text-decoration:none; margin-right: 12px; }
main { padding: 16px; }