1. Use following codes in the styles.css file, which is located in the css folder.You can use it at the bottom of the file

 .site_preloader{
    position: fixed;
    width: 100%;
    height: 100%;
    background-color: rgba(255, 255, 255, 0.95);
    z-index: 999;
    left: 0;
    top: 0;
    display: -webkit-box;
    display: -ms-flexbox;
    display: flex;
    -webkit-box-orient: vertical;
    -webkit-box-direction: normal;
        -ms-flex-direction: column;
            flex-direction: column;
    -webkit-box-pack: center;
        -ms-flex-pack: center;
            justify-content: center;
}


.loader,
.loader:after {
  border-radius: 50%;
  width: 7em;
  height: 7em;
}


.loader {
  margin: 50px auto;
  font-size: 10px;
  position: relative;
  text-indent: -9999em;
  border-top: 3px solid rgba(2, 32, 47, 0.8);
  border-right: 3px solid rgba(2, 32, 47, 0.8);
  border-bottom: 3px solid rgba(2, 32, 47, 0.8);
  border-left: 3px solid #ffffff;
  -webkit-transform: translateZ(0);
  -ms-transform: translateZ(0);
  transform: translateZ(0);
  -webkit-animation: load8 1.1s infinite linear;
  animation: load8 1.1s infinite linear;
}
@-webkit-keyframes load8 {
  0% {
    -webkit-transform: rotate(0deg);
    transform: rotate(0deg);
  }
  100% {
    -webkit-transform: rotate(360deg);
    transform: rotate(360deg);
  }
}
@keyframes load8 {
  0% {
    -webkit-transform: rotate(0deg);
    transform: rotate(0deg);
  }
  100% {
    -webkit-transform: rotate(360deg);
    transform: rotate(360deg);
  }
}


2.Use following codes in the custom.js file, which is located in the Js folder.Please paste the codes, within line 120 to 130.

function custom(){
        $('.site_preloader').fadeOut(1000, function () {
            $('this').remove();
        });

    }
$(document).ready(function () {
        custom();
    });


3. Now you need to call the preloader from every html pages.like index.html type.Please delete line from 70 to 81 in each html page, and use their the following codes.

<div class="site_preloader">
      <div class="loader"></div>

    </div>