.preloader {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 9999;
    background-image: url('../img/ajax-loading.gif');
    background-repeat: no-repeat; 
    background-color: #FFF;
    background-position: center;
 }

 html, body {
    max-width: 100%;
    overflow-x: hidden;
}