I'm testing now for over a half year and finally found a way to make a mobile menu.
But there is one bad thing who didnt want to go right.
The Content of the Mobile Menu will not be centered when the size of the site change.
I already tested to fix it to the center but it still went to the right side.
I made there some Breakpoints but if the site has a size between them the menu move and is not centerd. just the Content the Hamburger
Menu on the top is still right.
Maybe the Screenshots help you to help me.
(sorry bad English)
Not 100% sure, but I found, it is very important, not to pin on fluid width breakpoints.
It also is important to set elements to be responsive in width – therefore it is mostly necessary to create the text boxes/the menu wide enough, so they still fit in smallest width 320. That should be possible between 380 and 320 with no big problem.