Camera rotation and crosshair.

Hi, guys. Help please!! How i can do limit rotation in axis x?. Math.Clamp - not work. It work for Y, but it not work for X.

rotationX = transform.localEulerAngles.y + Input.GetAxis("Mouse X") * sensitivityX;
			rotationY = Mathf.Clamp (rotationX, minimumX, maximumX);

And i have one more question. How i can do this crosshair. I think, what i can measure distance of raycast spawnpain—>crosshairpoint.

// for angle limitation look at Look()

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

public class CameraController : MonoBehaviour
{
public PlayerManager player;
public float sensitivity = 100f;
public float clampAngle = 85f;

private float verticalRotation;
private float horizontalRotation;

private void Start()
{
    verticalRotation = transform.localEulerAngles.x;
    horizontalRotation = player.transform.eulerAngles.y;
}

private void Update()
{
    Look();
    Debug.DrawRay(transform.position, transform.forward * 2, Color.red);
}

private void Look()
{
    float _mouseVertical = -Input.GetAxis("Mouse Y");
    float _mouseHorizontal = Input.GetAxis("Mouse X");

    verticalRotation += _mouseVertical* sensitivity * Time.deltaTime;
    horizontalRotation += _mouseHorizontal * sensitivity * Time.deltaTime;

    verticalRotation = Mathf.Clamp(verticalRotation, -clampAngle, clampAngle);

    transform.localRotation = Quaternion.Euler(verticalRotation, 0f, 0f);
    player.transform.rotation = Quaternion.Euler(0f, horizontalRotation, 0f);
}

}