I have similar remarks. On OSX, the tab and the url bars are too big, they seem out of place.. Also, the black tab bar seems strange to me as I have a black OSX menu bar..
You can make the tab bar and url bar smaller by going to the menu > customize > density > compact.
Thanks! By the way, for those who read this, to change the theme is menu > customize > theme.. These things are not easy to find!
Thank you so much. That change, combined with the switch to the Light theme, makes Firefox so incredibly better on macOS.
yeah this was such a huge step up, thanks so much. that circled back button was especially driving me nuts so that going away instantly improved my take on this :D