Thinning down FireFox 4's Tab Bar

FireFox4 Beta 9 is out and they've made great improvements toward efficient vertical space use. Now when you maximize the main window the tabs move into the title bar! Here's how to set the tabs to always be in the Title Bar of the window even when not maximized.


Setting FF4's Tabs to Always be in the Title Bar


We need to add a couple of lines to your userChrome.css file. The userChrome.css file is located in the following locations:

XP: C:\Documents and Settings\<user>\Application Data\Mozilla\Firefox\Profiles\<profile>\chrome\
Vista\7: C:\Users\<user>\AppData\Roaming\Mozilla\Firefox\Profiles\<profile>\chrome\

Open that file in Notepad or another text editor and add the following lines to it:

@namespace url("");

#main-window[sizemode=normal][tabsontop="true"] #toolbar-menubar[autohide="true"] {
#main-window[sizemode=normal] #navigator-toolbox[tabsontop="true"] > #toolbar-menubar[autohide="true"] ~ #TabsToolbar {
padding-left: 8px !important;
padding-right: 8px !important;
height: 22px !important;

You'll also need to set FireFox to always display the tab bar (Options > Tabs > Always show the tab bar) so as not to cause issues when only a single tab is open.

Most credit for this version goes to sdrocking with this post as

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