Camera Relative Movement

I'm trying to write my own controller for a third person character and I'm having some trouble making the character move relative to a camera i.e. pressing up will always make the character walk away from the camera, pressing right will always cause the character to move right relative to the camera.

Here's my current code for setting the rotation of the character:

 private void updateRotation(){
         Transform cameraTransform = theCamera.transform;
         // forward of the camera on the x-z plane
         Vector3 cameraForward = theCamera.transform.TransformDirection(Vector3.forward);
         cameraForward.y = 0f;
         cameraForward = cameraForward.normalized;
         
         Vector3 cameraRight = new Vector3(cameraForward.z, 0.0f, -cameraForward.x);
         
         float vert = Input.GetAxisRaw("Vertical");
         float hor = Input.GetAxisRaw("Horizontal");
         
         Vector3 tempTarget = hor * cameraRight + vert * cameraForward;
         if (tempTarget!= Vector3.zero){
             theController.moveDirection = Vector3.RotateTowards(theController.moveDirection, tempTarget, theController.rotSpeed * Mathf.Deg2Rad * Time.deltaTime, 1000);
             theController.moveDirection = theController.moveDirection.normalized;
             theController.transform.rotation = Quaternion.LookRotation(theController.moveDirection);
         }
         
     }

And here is how my controller moves the character forward:

 private void moveCharacter(){
         transform.Translate(transform.forward*moveSpeed*Time.deltaTime);
 }

Currently the character moves relative to the camera at first, then seems to "lose it's axis" so to speak. Any help would be appreciated.