Bookmark toolbar takes too muck space
Here is screenshot demonstraiting the problem: Screenshot
Main Toolbar is disabled Bookmark toolbar contains a few folders and located at the top row along with the navigation buttons and page tabs.
The problem is bookmark panel takes too much space (it is too width) - lots of free space is unused.
Wšykne wótegrona (1)
It never occurred to me to put the bookmarks on the tab bar. They don't seem to auto-size correctly there. (On other bars, you can re-fit the bookmarks using: View > Toolbars > Customize or right-click blank area of tab bar or navigation toolbar > Customize, then just clicking Done.)
There are some methods for applying style rules to the Firefox UI that might help in this case. For example, you might be able to specify a maximum width for the bookmarks part of the bar. For example:
#TabsToolbar #personal-bookmarks, #TabsToolbar #PlacesToolbar {max-width:350px !important;}
To apply such a rule, you can use the Stylish extension or the userChrome.css file (as described in other threads, but I'm short of time to search them up at the moment).