:focus { outline: 3px solid; outline-offset: 2px; }
button { cursor: pointer; }
#choices button { display: block; margin: .25rem 0; padding: .5rem .75rem; }
#choices button.selected { border: 2px solid; }
main { max-width: 720px; margin: 2rem auto; padding: 1rem; font-family: system-ui, -apple-system, Segoe UI, Roboto, Arial, sans-serif; }
h1 { font-size: 1.5rem; margin-bottom: 1rem; }
ol { padding-left: 1rem; }
textarea { width: 100%; }
pre { background: #f6f8fa; padding: .75rem; overflow: auto; }