.preloader{
    display: block;z-index: 9999;
    position: absolute;
    background: #3e3f95;
    width: 100%;
    height: 100%;
    top: 0;
    left: 0;
    text-align: center;
    padding: 20%;opacity: .8;
    color: #ffffff;
}

.align-center{
    display:flex;
    justify-content:center;
    align-items:center;
}