#preload-block {
  background-color: #fff;
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: 99999;
}

#preload-block .square-block {
  background: url('../images/preloader.gif') no-repeat center center;
  width: 80px;
  height: 80px;
  text-align: center;
  position: relative;
  top: 50%;
  margin: 0 auto;
}