Tree Style Tabs - Hover Hide/Show
Automatically show/hide Firefox's Tree Style Tabs Extention expanding over the main content. This is unlike the suggested auto hide/show hover which changes the width of the main content to make space.
Example
The suggested hover hide is pictured on the left. The changes in hoverhide.css are on the right.1
Install
Copy the contents of hoverhide.css to your Firefox profiles userChrome.css file.