FF94.0.2 (x64): Tabs have unnecessary space above them when window is maximized

[ghost]

Sanity checks (must complete)

• [√ ] I have read and followed the installation instructions in the README
• [√ ] I have not modified the userChrome.css file
• [√ ] I have tested the latest release for my Firefox version, or commit on master/beta branch (beta is for Firefox Beta only)

Describe the bug
have space above firefox tabs.not the same as chrome

To Reproduce
Open 94.0.2 (x64 ) with this modification on Windows 10 and maximize the window

Screenshots
How tabs in maximized windows in FF94.0.2 (x64 ) currently look (notice space above the tab):

How the tabs should look (and how they currently look in Chrome):

System info

• OS: Windows 10
• Firefox version: 94.0.2 (x64 )

[inxomnyaa]

this (or maybe something else) also causes misalignment of the new tab and close tab buttons

[baiyanglevi]

I also encountered this on in 95.0 (x64) on Windows 10.
and the misalignment in urlbar still exists...