Как передавать параметр css при скроле?

var elem = document.getElementById('blockId'); 
var scale = 1; 
var scaleStep = 0.0001; 
 
if (elem.addEventListener) { 
  if ('onwheel' in document) { 
    // IE9+, FF17+, Ch31+ 
    elem.addEventListener("wheel", onWheel); 
  } else if ('onmousewheel' in document) { 
    // устаревший вариант события 
    elem.addEventListener("mousewheel", onWheel); 
  } else { 
    // Firefox < 17 
    elem.addEventListener("MozMousePixelScroll", onWheel); 
  } 
} else { // IE8- 
  elem.attachEvent("onmousewheel", onWheel); 
} 
 
function onWheel(e) { 
  e = e || window.event; 
 
  // wheelDelta не дает возможность узнать количество пикселей 
  var delta = e.deltaY || e.detail || e.wheelDelta; 
  scale = scale + delta*scaleStep; 
  elem.innerHTML = scale; 
  elem.style.transform = 'scale(' + scale + ')'; 
 
  e.preventDefault ? e.preventDefault() : (e.returnValue = false); 
}

    .block{ 
      width:200px; 
      height:200px; 
      background:lightgrey; 
    }

<div class="block" id="blockId"> 
</div>

var elem = document.getElementById('blockId'); 
var scale = 1; 
var scaleStep = 0.0001; 
 
window.onscroll = function() { 
  var scrolled = window.pageYOffset || document.documentElement.scrollTop; 
  scale = scale + scrolled *scaleStep; 
  elem.innerHTML = scale; 
  elem.style.transform = 'scale(' + scale + ')'; 
}

    .block{ 
      width:200px; 
      height:200px; 
      background:lightgrey; 
    }

<div class="block" id="blockId"> 
</div>