#loading-spinner {
    display: block;
    width: 80px;
    height: 80px;
    margin: 0 auto 2em auto;
}

#loading-spinner:after {
    content: " ";
    display: block;
    width: 64px;
    height: 64px;
    margin: 8px;
    border-radius: 50%;
    border: 6px solid;
    border-color: grey transparent grey transparent;
    animation: loading-spinner-animation 1.2s linear infinite;
}

@keyframes loading-spinner-animation {
    0% {
        transform: rotate(0deg);
    }
    100% {
        transform: rotate(360deg);
    }
}