.central-spinner:before {
    content: "";
    position: fixed;
    top: 0;
    left: 0;
    background: black;
    opacity: 0.3;
    width: 100%;
    height: 100%;
}

.central-spinner {
    position: fixed;
    top: 50vh;
    left: 50vw;
    z-index: 9999;
}

.loader{
    width: 70px;
    height: 70px;
    border-radius: 100%;
    position: relative;
    margin: 0 auto;
}

.loader:before, .loader:after{
    content: "";
    position: absolute;
    top: -35px;
    left: -35px;
    width: 100%;
    height: 100%;
    border-radius: 100%;
    border: 5px solid transparent;
    border-top-color: #5cb85c;
}

.loader:before{
    z-index: 100;
    animation: spin 1s infinite;
}

.loader:after{
    border: 5px solid #ccc;
}

@keyframes spin{
    0%{
        -webkit-transform: rotate(0deg);
        -ms-transform: rotate(0deg);
        -o-transform: rotate(0deg);
        transform: rotate(0deg);
    }

    100%{
        -webkit-transform: rotate(360deg);
        -ms-transform: rotate(360deg);
        -o-transform: rotate(360deg);
        transform: rotate(360deg);
    }
}