body { font: 16px/1.5 system-ui, sans-serif; margin: 0; color: #1d2329; }
main { max-width: 40rem; margin: 0 auto; padding: 1.5rem; }
[hidden] { display: none; }
code { font-size: 0.9em; }
button { font: inherit; padding: 0.3rem 1rem; }
progress { display: block; width: 100%; margin: 1rem 0; }
.error { color: #b3261e; }
.success { color: #1b6e3a; font-weight: 600; }