.overlay {
    display: none;
    position: fixed;
    width: 100%;
    height: 100%;
    top: 0;
    left: 0;
    z-index: 9999999;
    background: rgb(23 23 23 / 78%) url('../../img/loader.gif') center no-repeat;
    background-size: 50px;
}

body.loading .overlay {
    display: block;
}