Orange Navbar: large content and scroll on mobile

[julien-deramond]

Description

If you've got an Orange Navbar with loads of stuff or a dropdown that's bigger than your phone screen, there's a glitch on mobile. Yep, you end up having to scroll all over the place just to see the hidden Orange navbar part. Not exactly the smoothest user experience.

It can be seen directly at https://boosted.orange.com/docs/5.2:

Unless we find a fix that works for everything, we might have to shake things up for the Orange navbar. Thinking of turning it into an offcanvas or a fullscreen modal on mobile could do the trick. That way, it would cover everything else, making it clear that it's the main focus.

Note: We possibly need to revert what's been done as a quick and dirty patch in f9c77d7.