Customization – How can I hide the bottom navigation bar in the Youtube app?

I want to hide lower navigation bar (not system-wide navigation bar) or at least a Chrome toolbar that shows / hides when scrolling. I have no idea, because I could not find anything to hide the bottom navigation bar, except programmatically.

That's what I'm talking about.

IMG: lower navigation bar

I'm using a rooted OnePlus 6 with Android 8.1 and Xposed Framework.

The reason I wanted that: I would prefer that real screen pages show something dynamic from Youtube as part of the scrolling. This bar is in my way to reach the maximum size of the view.