Did you ever notice that Firefox tabs are bland? The question then is, how do you make the active tab stand-out from the rest of the tabs? Here's how.
In the profile directory (path: %appdata%\Mozilla\Firefox\Profiles\xxxxxxxx.default), there is a folder named "chrome" (no relation to Google's browser). You will find a file named userChrome.css inside it. If the file does not exist, create it. It is a simple text file that we will edit.
Open the file in notepad and add the following lines of code:
/* 225 pixels to the active tab */ .tabbrowser-tab[selected]:not([pinned])[fadein] { min-width: 225px !important; }
What the above code does is to expand the current active tab in Firefox to 225 pixels wide. It overrides Firefox default tab width of 100 pixels. If 225 pixels is too big or too small for you, adjust as necessary. When you open more tabs, the other tabs will shrink making the active tab stand out, like the screenshot below.
Now your active tabs will stand out from the rest of the other open tabs. Another cool feature of this tweak is when you switch to another tab, the other tab fades in to increase the tab width. Describing it in this post doesn't do it much justice. It is better to see it for yourself.
This tweak has helped me out a lot and made my Firefox experience a bit more worthwhile.