body { font-family: system-ui, sans-serif; max-width: 32rem; margin: 0 auto; padding: 1rem; }
label { display: block; margin: 0.75rem 0; }
/* 16px 未満だと iOS Safari が入力時に拡大する。 */
input, select, button { display: block; box-sizing: border-box; width: 100%; margin-top: 0.25rem; padding: 0.5rem; font-size: 1rem; }
output { display: block; margin: 1rem 0; font-family: monospace; font-size: 1.1rem; overflow-wrap: anywhere; }
[hidden] { display: none; }