.loader {
    position: fixed;
    width: 100%;
    left: 0px;
    right: 0px;
    top: 0px;
    bottom: 0px;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 9;
}

    .loader:before {
        background: rgba(255,255,255,0.8);
        display: inline-block;
        content: "";
        width: 100%;
        height: 100%;
        position: absolute;
    }