.loading {
    position: fixed;
    top: 0; right: 0;
    bottom: 0; left: 0;
    background: rgba(0, 0, 0, 0.6);
    z-index: 1000;
}
.loader {
    left: 50%;
    margin-left: -4em;
    font-size: 10px;
    border: .8em solid rgba(218, 219, 223, 1);
    border-left: .8em solid rgba(58, 166, 165, 1);
    animation: spin 1.1s infinite linear;
}
.loader, .loader:after {
    border-radius: 50%;
    width: 8em;
    height: 8em;
    display: block;
    position: absolute;
    top: 50%;
    margin-top: -4.05em;
}

@keyframes spin {
    0% {
        transform: rotate(360deg);
    }
    100% {
        transform: rotate(0deg);
    }
}