:root{color-scheme:light dark;font-family:system-ui,-apple-system,sans-serif}body{margin:0;background:#f4f4f5;color:#18181b}.app{max-width:32rem;margin:3rem auto;padding:0 1.25rem}h1{margin-bottom:.25rem}.subtitle{margin-top:0;color:#71717a;font-size:.9rem}.todo-form{display:flex;gap:.5rem;margin:1.5rem 0}.todo-form input{flex:1;padding:.6rem .8rem;border:1px solid #d4d4d8;border-radius:.5rem;font-size:1rem}.todo-form button{padding:.6rem 1rem;border:none;border-radius:.5rem;background:#2563eb;color:#fff;font-size:1rem;cursor:pointer}.todo-form button:hover{background:#1d4ed8}.todo-list{list-style:none;padding:0;display:flex;flex-direction:column;gap:.5rem}.todo-item{display:flex;align-items:center;gap:.6rem;background:#fff;border:1px solid #e4e4e7;border-radius:.5rem;padding:.6rem .8rem}.todo-item span{flex:1}.todo-item.done span{text-decoration:line-through;color:#a1a1aa}.todo-item button{border:none;background:transparent;color:#ef4444;cursor:pointer;font-size:1.1rem}.error{background:#fee2e2;color:#991b1b;padding:.6rem .8rem;border-radius:.5rem}