:root{color:#172033;background:#f6f8fb;font-family:system-ui,sans-serif}body{margin:0}main{max-width:72rem;margin:auto;padding:1.5rem}header{border-bottom:1px solid #ccd3df;margin-bottom:1rem}aside[role=alert]{background:#fff4cc;border:2px solid #9a6400;padding:.75rem}button:disabled{cursor:not-allowed;opacity:.65}@media (width<=640px){main{padding:1rem}}