<style>

/*====================================
* Preloader Start
======================================*/
.progress {
      position: fixed;
      top:0px;
      height: 4px;
      display: block;
      width: 100%;
      background-color: white;
      border-radius: 2px;
      background-clip: padding-box;
      /*margin: 0.5rem 0 1rem 0;*/
      overflow: hidden;
      z-index:999999999;
    }
    .progress .indeterminate {
background-color:black; }
    .progress .indeterminate:before {
      content: '';
      position: absolute;
      background-color: #2C67B1;
      top: 0;
      left: 0;
      bottom: 0;
      will-change: left, right;
      -webkit-animation: indeterminate 2.1s cubic-bezier(0.65, 0.815, 0.735, 0.395) infinite;
              animation: indeterminate 2.1s cubic-bezier(0.65, 0.815, 0.735, 0.395) infinite; }
    .progress .indeterminate:after {
      content: '';
      position: absolute;
      background-color: #2C67B1;
      top: 0;
      left: 0;
      bottom: 0;
      will-change: left, right;
      -webkit-animation: indeterminate-short 2.1s cubic-bezier(0.165, 0.84, 0.44, 1) infinite;
              animation: indeterminate-short 2.1s cubic-bezier(0.165, 0.84, 0.44, 1) infinite;
      -webkit-animation-delay: 1.15s;
              animation-delay: 1.15s; }

    @-webkit-keyframes indeterminate {
      0% {
        left: -35%;
        right: 100%; }
      60% {
        left: 100%;
        right: -90%; }
      100% {
        left: 100%;
        right: -90%; } }
    @keyframes indeterminate {
      0% {
        left: -35%;
        right: 100%; }
      60% {
        left: 100%;
        right: -90%; }
      100% {
        left: 100%;
        right: -90%; } }
    @-webkit-keyframes indeterminate-short {
      0% {
        left: -200%;
        right: 100%; }
      60% {
        left: 107%;
        right: -8%; }
      100% {
        left: 107%;
        right: -8%; } }
    @keyframes indeterminate-short {
      0% {
        left: -200%;
        right: 100%; }
      60% {
        left: 107%;
        right: -8%; }
      100% {
        left: 107%;
        right: -8%; }
}

/*====================================
* Preloader End
======================================*/
</style> 

 

 

        <!-- Page Loader Start -->
  <div class='progress' id='PreLoaderBar'>
        <div class='indeterminate'/>
    </div>
           <!-- Page Loader End -->

     <script>
    document.onreadystatechange = function () {
            if (document.readyState === &quot;complete&quot;) {
                console.log(document.readyState);
                document.getElementById(&quot;PreLoaderBar&quot;).style.display = &quot;none&quot;;
            }
        }
    </script>

Preview: preview on the top !