.loader{
    position: fixed;
    left: 0px;
    top: 0px;
    width: 100%;
    height: 100%;
    z-index: 9999;
    background: url('../assets/images/loading.gif')
    50% 50% no-repeat rgb(255,255,255);
    background-size: 20%;
    animation: fadeIn 3s ease-in;
}

@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 0.5;
    }
}