SVG loading animation

I have two separate html files, one is a menu, and the other is a page loading animated svg. How can I set the page loader to fade out, and the menu page to fade in after it has completed loading?

Working example anywhere?
I personally use codepen

yes of course they are both on codepen here is the UI/ And here is loading animation.

Can’t you just use the keyframe animations to time it as how you want it?