CSS for fixed/centered throbber

Hello,

I thought this might be some useful copy/paste CSS for others to use, since the throbber only exists in the live code during the AJAX transition (making it difficult to "grab" with code inspector). I used the CSS to center the throbber vertically and horizontally, and to overlay the entire page with faded white (you can change the RGB values and opacity to whatever you wish).

.ajax-progress {
    position: fixed;
    z-index: 99999999;
    background: rgb(255,255,255,0.6);
    text-align: center;
    width: 100%;
    height: 100%;
    top:0;
    left:0;
}
.ajax-throbber {
    left: 0;
    position:absolute;
    right:0;
    top: 50%;
    transform: translateY(-50%);
}