Get unique styles assigned to any element matching a query selector

get_unique_styles.js

[...document.querySelectorAll("#targets")].forEach(targetEl  => {
  var targetStyles = window.getComputedStyle(targetEl);
  var comparisonEl = document.createElement(targetEl.tagName);
  var comparisonStyles = window.getComputedStyle(comparisonEl);
  var cleanStyles = {};
  Object.entries(targetStyles).forEach(style=>{
    if(comparisonStyles[style[0]] !== style[1]){
      cleanStyles[style[0]] = style[1];
    }
  });
  console.log('CLEAN SET (' + Object.keys(cleanStyles).length + ' rules):',cleanStyles);

  comparisonEl.remove()
});