body{font-family:Arial,sans-serif;margin:0;padding:0;background-color:#f5f5f5}.app{max-width:600px;margin:0 auto;padding:20px}.task-input{display:flex;margin-bottom:20px}.task-input input{flex:1;padding:10px;font-size:16px;border:1px solid #ccc;border-radius:4px}.task-input button{padding:10px 20px;margin-left:10px;font-size:16px;background-color:#007bff;color:#fff;border:none;border-radius:4px;cursor:pointer}.task-list{list-style:none;padding:0}.task-item{display:flex;align-items:center;padding:10px;margin-bottom:10px;background-color:#fff;border-radius:4px;box-shadow:0 2px 4px #0000001a}.task-item.completed span{text-decoration:line-through;color:#888}.task-item input[type=checkbox]{margin-right:10px}.task-item button{margin-left:auto;padding:5px 10px;background-color:#dc3545;color:#fff;border:none;border-radius:4px;cursor:pointer}