:root { font-family: system-ui, sans-serif; color-scheme: dark light; }
body { margin: 2rem; }
main { max-width: 900px; margin-inline: auto; }
.card { border: 1px solid #ccc; padding: 1rem; border-radius: 10px; margin-top: 1rem; }
.row { display: flex; gap: .5rem; align-items: center; margin-top: .5rem; }
input, select, button { padding: .5rem; }
pre { background: #111; color: #0f0; padding: .75rem; border-radius: 8px; overflow: auto; }