The CSS files in this repo enable you to configure Firefox so that tabs slide down from the navigation bar on hover or on focus, and hide otherwise. This saves vertical space when using Firefox.
You should ensure that you have custom styling enabled in Firefox.
Afterward, copy the files from this repo in the chrome folder
of your profile folder (as found in about:support).
If you want to clone and track the Git repo directly, I recommend
cloning the repo into a subdirectory of chrome. Then, you can create
a blank userChrome.css in the chrome folder and
he single line:
@import(firefox-slidedown-tabs/userChrome.css)This allows you to combine firefox-slidedown-tabs with other
customizations in your base userChrome.css.
If you want to place the Git repo folder elsewhere on your computer,
a good idea is to place a symbolic link to it within the chrome
folder.
First go to about:config in Firefox and set
toolkit.legacyUserProfileCustomizations.stylesheets to true.
Second, go to about:support in Firefox, find Profile Directory,
and click Open Directory. This will bring you to the profile
folder discussed above.
Several of the color values and sizes are currently hard-coded for my Firefox setup (Firefox 78, Compact Toolbar, Mozilla Dark theme). I might experiment with some other themes to make the slidedown tabs more robust.
If you have suggestions on how to make the code more general, I am open to pull requests and contributors.
As noted above, currently color values and sizes must be manually tweaked for your theme.
Using drag-and-drop to swap around the order of tabs currently does not work without introducing an ugly black bar that defeats the purpose of saving space. (The rule that creates this black bar is commented out by default). For now, I recommend installing a Firefox Extension that can help you move tabs by keyboard shortcut, if you desire to move your tabs.
Dragging tabs between Firefox windows, or out of the window to create a new window, does work.
Because I don't use typically menu bar or bookmarks toolbar, I did not initially notice that these break the position of the slidedown tabs. I will investigate and attempt a fix.
Much of the initial code is based on two answers by cor-el in the Firefox Support Forums. Links to the relevant answers are provided in code.