.spinner
{
    position: fixed;
    border: solid 16px silver;
    border-top: solid 16px #337ab7;
    border-radius: 50%;
    width: 80px;
    height: 80px;
    top: 50%;
    bottom: 50%;
    left: 50%;
    right: 50%;
    animation: spin 700ms linear infinite;
}

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

    100%
    {
        transform: rotate(360deg);
    }
}