In the world of web design, and even if you are simply a blogger wishing to change a few tiny things, there comes a time when you need to change elements in your theme’s style sheet. Knowing what to change and where to find it can be the biggest hurdle, but there is a simple tool available that is the web designer’s secret weapon.
The Firebug extension for Mozilla’s Firefox (and Firebug Lite for Chrome) can make short work of finding and changing css elements in your design. It overlays the rendered code of your site in a split screen so you can see and change the HTML/CSS, while being able to instantly view the change.
In FireFox, go to the Tools menu, select “Add Ons” and under “Get Add Ons” type Firebug in the search box. Click the Install button. You may need to restart Firefox after installation.