CSS: Moving background on mouse over muovere in base al movimento del mouse

css.html

<div id="top-image"></div>

<style>
  #top-image {
background:url('https://d3ui957tjb5bqd.cloudfront.net/images/screenshots/products/0/8/8905/red-rocks-park-o.jpg') -25px -50px;
position:fixed ;
top:0;
width:100%;
z-index:0;
  height:100%;
  background-size: calc(100% + 50px);
}
</style>

<script>
  $(document).ready(function() {
var movementStrength = 25;
var height = movementStrength / $(window).height();
var width = movementStrength / $(window).width();
$("#top-image").mousemove(function(e){
          var pageX = e.pageX - ($(window).width() / 2);
          var pageY = e.pageY - ($(window).height() / 2);
          var newvalueX = width * pageX * -1 - 25;
          var newvalueY = height * pageY * -1 - 50;
          $('#top-image').css("background-position", newvalueX+"px     "+newvalueY+"px");
});
});
</script>