navbar takes up lots of vertical space on mobile

[ldct]

Navigating directly to python.org on mobile, I see

There is a button to "close" (really, scroll down) the navbar, but it should not be open by default

[fimion]

Would it be helpful if I took a crack at this?

[berkerpeksag]

@fimion please go ahead and feel free to ask any questions! :)

[scottilee]

This is being addressed with #1446