The Firefox scrollbar is very narrow on Ubuntu. This is very annoying. But since I am using the MATE desktop and GTK 3.0, I can fix this easily.
Add this line to the ~/.config/gtk-3.0/settings.ini file, and this will force Firefox to use the scrollbar defined by the theme instead.
gtk-primary-button-warps-slider=false |
The file should look like this.
[Settings] gtk-application-prefer-dark-theme=0 gtk-primary-button-warps-slider=false |
Then, Firefox will be easier to use on Linux. GTK makes this very easy.
Open a GTK application like Pluma with this environment variable set, and it will force that application to use that theme.
env GTK_THEME="BlackMATE" /usr/bin/pluma |
Control which GTK theme a specific application uses on Linux.