How to find unused classes in my HTML?

var classesEvery = [];
var elementsEvery = document.querySelectorAll('*');
for (var i = 0; i < elementsEvery.length; i++) {
  var classes = elementsEvery[i].className.toString().split(/\s+/);
  for (var j = 0; j < classes.length; j++) {
    var thisClass = classes[j];
    if (thisClass && classesEvery.indexOf(thisClass) === -1)
      classesEvery.push(thisClass);
  }
}
console.log(classesEvery);

.hidden {
  display: none;
}

<!-- Some random HTML code. -->
<div ng-controller="HomeController" class="container hidden">

  <span>Simple Notifications:</span>
  <div class="rows">
    <div class="col-md-2"><button class="btn btn-primary" href ng-click="simple()">Simple notification</button></div>
    <div class="col-md-2"><button class="btn btn-warning" href ng-click="warning()">Warning notification</button></div>
    <div class="col-md-2"><button class="btn btn-success" href ng-click="success()">Success notification</button></div>
    <div class="col-md-2"><button class="btn btn-danger" href ng-click="error()">Error notification</button></div>
    <div class="col-md-2"><button class="btn btn-grimace" href ng-click="wait()">Wait notification</button></div>
    <div class="col-md-2"><button class="btn btn-primary" href ng-click="pop()">Link to other page</button></div>
  </div>
  <hr/>
  <span>Addding Option from Script:</span>
  <div class="rows">
    <div class="col-md-6">
      <Span>With CLose button</span>
      <button class="btn btn-primary" href ng-click="close()">Close Button </button>
    </div>
    <div class="col-md-6">
      <Span>Fade after 1 Sec</span>
      <button class="btn btn-primary" href ng-click="timeout()">Html notification</button>
    </div>
  </div>
  <br/>
  <hr/>
  <span>Custom Notification and Body output type:</span>
  <div class="rows">
    <div class="col-md-3"><button class="btn btn-primary" href ng-click="Custom_temp()">Custom template</button></div>
    <div class="col-md-3"><button class="btn btn-primary" href ng-click="trusted_html()">Trusted HTML</button></div>
    <div class="col-md-3"><button class="btn btn-primary" href ng-click="default_temp()">Default Template</button></div>
    <div class="col-md-3"><button class="btn btn-primary" href ng-click="file_custom_temp()">Including file from Folder</button></div>
  </div>
  <script type="text/ng-template" id="myTemplate.html">
    <div class="Custom_temp_html">
      <p>Notice, custom temlate is not in the list</p>
    </div>
  </script>
</div>