Add animated gif on loader

[hectordufau]

Is it possible add an external animated gif image above or below loading bar?

For example: I want to create a new pace theme, adding an animated gif above loading-bar (reference: pace-theme-loading-bar.css).

I tried use this:

-webkit-mask-image: url(images/runningdog.gif); mask-image: url(images/runningdog.gif); -webkit-mask-size:20px 20px; mask-size:20px 20px;

But I don't know if it is correct and where css section I add it.

Would you like share an example?