How to return 1 pixel in top firefox menu?

Question

Mozilla Firefox

Actually, in FireFox, for some reason, they removed 1px in the top menu, now, having brought the mouse all the way, I cling not to the window border, but to the tab. It is very uncomfortable. Help return "as was."

Answer 1

Create a chrome folder in the profile folder and the userChrome.css file in it
With the following code:

tab>tab,tabs{
  margin-top: 1px !important;
}

Answer 2

Through the Windows registry: in HKCU\Control Panel\Desktop\WindowMetrics, change the PaddedBorderWidth or BorderWidth property to a value slightly larger than it was before.

Answer 3

Turn on the menu bar and there will be no such problem.
upd: The application does not help.
upd2:
As an option - right in the empty space next to the tab - configure - button "Header" at the bottom left
It is certainly not 1px in height, but still.