Sorry, the ability to add "custom toolbars" by the user is gone from Firefox, and the "tricks" that once worked to add blank or almost blank space in the toolbar area is gone.

That coupled almost the current almost complete elimination of add-on toolbars makes those "lightweight themes (which were originally named Personas when they were introduced for Firefox 3.6) almost worthless when the "theme developer" follows the specifications as originally set forth by Mozilla and still "enforced" during the submission procedure.

To see more of the lightweight theme you can set a min-height to the navigator-toolbox with code in the userChrome.css file or by using the Stylish extension. Add code to the userChrome.css file below the default @namespace line.

• http://kb.mozillazine.org/userChrome.css

@namespace url("http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"); /* only needed once */

#navigator-toolbox {min-height:200px!important; box-shadow:ThreeDShadow 0 -1px inset !important;}

You can use the button on the "Help -> Troubleshooting Information" (about:support) page to go to the current Firefox profile folder or use the about:profiles page.

• Help -> Troubleshooting Information -> Profile Directory:
  Windows: Show Folder; Linux: Open Directory; Mac: Show in Finder
• http://kb.mozillazine.org/Profile_folder_-_Firefox

• create the chrome folder (lowercase) in the <xxxxxxxx>.default profile folder if this folder doesn't exist
• use a plain text editor like Notepad to create a (new) userChrome.css file in the chrome folder (file name is case sensitive)
• paste the code in the userChrome.css file in the editor window
• make sure that the userChrome.css file starts with the default @namespace line
• make sure that you select "All files" and not "Text files" when you save the file via "Save file as" in the text editor as userChrome.css.
  otherwise Windows may add a hidden .txt file extension and you end up with a not working userChrome.css.txt file

CRAP!!!! I liked the personas.