body{font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Arial,sans-serif;background:#f4f6f8;margin:0;padding:0;color:#1a1a1a}.container{max-width:480px;margin:60px auto;background:#fff;border-radius:12px;padding:32px;box-shadow:0 2px 12px #00000014}h1{font-size:22px;margin-bottom:24px;color:#1d4ed8}.todo-form{display:flex;gap:8px;margin-bottom:20px}.todo-form input{flex:1;padding:10px 12px;border:1px solid #d1d5db;border-radius:8px;font-size:14px}.todo-form button{padding:10px 16px;background:#1d4ed8;color:#fff;border:none;border-radius:8px;cursor:pointer;font-size:14px}.todo-form button:hover{background:#1e40af}.todo-list{list-style:none;padding:0;margin:0}.todo-list li{display:flex;justify-content:space-between;align-items:center;padding:10px 0;border-bottom:1px solid #eee}.todo-list li span{cursor:pointer;flex:1}.todo-list li.done span{text-decoration:line-through;color:#9ca3af}.todo-list li button{background:transparent;border:none;color:#dc2626;cursor:pointer;font-size:13px}.error{color:#dc2626;font-size:14px}