Full screen menu

Hi There,

I’m looking into building a full screen menu for different websites. The problem I’m facing is after clicking on a button/link within that menu.

I want the page to load “behind” that menu and after loading I want that menu to collapse back to it initial state. I’m not able to find anything on youtube and/or online. Can someone please point me in the right direction or tell me what I need to do for that animation to take please?

Here’s an example of said menu;
Branding agency | MOQO