Rotate GameObject with children around itself on mouse drag

Hi, I'd like to rotate my GameObject with a set of spheres as children around itself. Until now I've written the following code:

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 
 public class ObjectRotator : MonoBehaviour{
     Vector3 mPrevPos = Vector3.zero;
     Vector3 mPosDelta = Vector3.zero;
 
     void Update(){
         if(Input.GetMouseButton(0)){
             mPosDelta = Input.mousePosition - mPrevPos;
             if(Vector3.Dot(transform.up, Vector3.up)>=0){
                 transform.Rotate(transform.up, -Vector3.Dot(mPosDelta, Camera.main.transform.right), Space.Self);
             }
             else{
                 transform.Rotate(transform.up, Vector3.Dot(mPosDelta, Camera.main.transform.right), Space.Self);
             }
             transform.Rotate(Camera.main.transform.right, Vector3.Dot(mPosDelta, Camera.main.transform.up), Space.Self);
         }
         mPrevPos = Input.mousePosition;
     }
 }

But this code does not work as I want to. I'd like that my GameObject stays in the same position, but on mouse drag it rotates. Could you help me please?