[Navigation Menyu] Example about use collapsible like viewport

[SalahAdDin]

How is the best way to use the viewport for creating collapsible vertical menus?

We see viewport is very important for creating gracefil animations, expecially when closing the menu:

When leaving the content, the viewport closes with a nice animation.

In contrast, when we don't use a viewport and we render the content, at opening we can see the animation, but at closing there is no animation:

The content is removed before the animation can proceed, avoiding it to happen.

Right now, we don't know how to make the viewoport to appear just below the hovered navigation item...

Could you guys help us to understand how to do it?

Thanks