How do I control the camera with my mouse?

I am trying to get the camera in my game to rotate in the direction that I am moving my mouse. (Like Minecraft). I have written code that rotates the camera based on the input from the mouse X and Mouse Y Axis'. Here is what I have:

using System.Collections; using System.Collections.Generic; using UnityEngine;

public class CameraController : MonoBehaviour {

 // Use this for initialization
 void Start () {
     
 }
 
 // Update is called once per frame
 void Update () {
     float MH = Input.GetAxis("Mouse X");
     float MV = -Input.GetAxis("Mouse Y");


     transform.Rotate(MV, 0, 0, Space.World);
     transform.Rotate(0, MH, 0, Space.World);
    


 }

}

Just moving the camera on one axis is fine, but when I add two axis' it starts to rotate on the z axis as well. I want to eliminate the movement on the z axis. How do I do this?