JS for parsing CSS numeric values followed by 'rem' unit and perform math operations over it

CSS units parser

//Open the file directly in the browser and run this script from the console
//Assumptions: The browser uses a <pre/> tag for showing the CSS code

var file = document.querySelector("pre");
    var fileContent = file.innerHTML;


    var newContent = fileContent.replace(/([\d.]+)(rem)/g, function(m){
      var measure = parseFloat(m.split("rem")[0]);
      var newMeasure = measure / 1.6;
      newMeasure = newMeasure.toFixed(2);

      return newMeasure+"rem";
    });

    file.parentNode.innerHTML = "<pre>"+newContent+"</pre>"