:root{color:#1a1a1a;background:#fafafa;font-family:system-ui,sans-serif;line-height:1.5}body{margin:0}main{max-width:40rem;margin:0 auto;padding:2rem 1rem}header{justify-content:space-between;align-items:center;display:flex}button{font:inherit;cursor:pointer;padding:.5rem 1rem}blockquote{background:#fff;border-left:4px solid #2563eb;margin:1.5rem 0;padding:1rem}.error{color:#b91c1c}