body{font-family:Arial,sans-serif;margin:0;padding:0;display:flex;justify-content:center;align-items:center;height:100vh;background-color:#f5f5f5}.app{background:#fff;padding:20px;border-radius:8px;box-shadow:0 2px 4px #0000001a;width:300px}.input-container{display:flex;margin-bottom:20px}.input-container input{flex:1;padding:8px;border:1px solid #ddd;border-radius:4px}.input-container button{margin-left:10px;padding:8px 12px;background-color:#007bff;color:#fff;border:none;border-radius:4px;cursor:pointer}.task-list{list-style:none;padding:0}.task-item{display:flex;justify-content:space-between;align-items:center;padding:8px;border-bottom:1px solid #ddd}.task-item.completed span{text-decoration:line-through;color:#888}.task-item button{background-color:#dc3545;color:#fff;border:none;border-radius:4px;padding:4px 8px;cursor:pointer}