[HowTo] Make Semi Transparant Menu Bar In Firefox

You can make Menubar in Firefox semi transparent like Google Chrome. When you type an address or search query into the address bar in Google Chrome, the drop-down list of history and search suggestions that appears is slightly transparent. Nothing extreme, but it adds a nice touch.
Here’s a quick trick that can make your Firefox semi transparent menu bar like in Google Chrome.

Follow the steps below (note: this is for Windows only):

1. Close your Firefox
2. Open your Firefox profile folder by entering the following in the address bar in Explorer or in the Run command:

   %appdata%MozillaFirefoxProfiles

   See the screenshot below:
   

3. Open the default folder, and then open the Chrome folder in it.
4. Open the userChrome.css file in an editor such as Notepad. If you do not have a userChrome.css file, open the userChrome-example.css file instead.
5. Add the following code to the end of the file:

   #PopupAutoCompleteRichResult[type="autocomplete-richlistbox"]
   {
       opacity: 0.9 !important;
   }

6. Save the file as userChrome.css in that same folder.
7. Open Firefox, and now your Awesome Bar’s drop-down list will be transparent. Actually, it may look even more awesome than Google Chrome’s address bar!