move camera relative to mouse position.

I want to make the camera stake to the player so i do this:

 transform.position = player.transform.position + offset;

making offset to give some space between the player and the camera.

Now I want to the camera move slightly to the position of the mouse to give more vision to the player so I added this:

         Vector3 mousePos = Input.mousePosition;
         mousePos.z = Camera.main.nearClipPlane;
         Vector3 worldPosition = Camera.main.ScreenToViewportPoint(mousePos);
         worldPosition = new Vector3(worldPosition.x - 0.5f , worldPosition.y - 0.5f ,0);
         worldPosition *= 2;

making the z position 0 so the player character to look at the curser in the future.

deduction 0.5 from X and Y to make the worldPosition in the centerof the screen.

but i can't add worldPosition to player.transform.position and offset becouse it will constantly add the worldPosition making the camera fly off the scene where it should be.

how do i add these variables to gather.

here is the full script:

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 
 public class CameraMovement : MonoBehaviour
 {
     [SerializeField] private GameObject player;
     [SerializeField] private Vector3 offset;
 
     private void Update()
     {
         Vector3 mousePos = Input.mousePosition;
         mousePos.z = Camera.main.nearClipPlane;
         Vector3 worldPosition = Camera.main.ScreenToViewportPoint(mousePos);
         worldPosition = new Vector3(worldPosition.x - 0.5f , worldPosition.y - 0.5f ,0);
         worldPosition *= 2;
         Debug.Log(worldPosition);
         
         
         transform.position = player.transform.position + offset + worldPosition;
     }
 
 }

and thank you for reading