.loader_bg{
    position: fixed;
    z-index: 999999;
    background: #fff;
    width: 100%;
    height: 100%;
}
.loader{
    
    border-radius: 50%;
    width: 150px;
    height: 150px;
    position: absolute;
    top: calc(50vh - 75px);
    left: calc(50vw - 75px);
}
.loader:before, .loader:after{
    content: '';
    border: 1em solid  #2443ac;
    border-radius: 50%;
    width: inherit;
    height: inherit;
    position: absolute;
    top: 0;
    left: 0;
    animation: loader 2s linear infinite;
    opacity: 0;
}
.loader:before{
    animation-delay: .5s;
}
@keyframes loader{
    0%{
        transform: scale(0);
        opacity: 0;
    }
    50%{
        opacity: 1;
    }
    100%{
        transform: scale(1);
        opacity: 0;
    }
}