Primefaces components CSS customization

Question

As I see in the primefaces documentation,

    1) To change the font-size of PrimeFaces components globally, use the `.ui-widget` style class. 
       An example with 12px font size.

        .ui-widget,
        .ui-widget .ui-widget {
               font-size: 12px !important;
         }

I have 2 questions on this:

1. Why is the .ui-widget written thrice in the above code?

2. For two different instances of tabView I want to customize its header background-color differently, but I couldnt find a way to do that. Is that even possible ?

Answer 1

In the style declaration they are comma delimiting the list of different class overrides. Specifically this piece of css states:

Classes ui-widget and ui-widget child elements of an element that has the class ui-widget.

As far as the header background is considered you might not have luck using simple CSS to modify the background color as I believe that it is likely using various different 1px wide GIF or JPG images repeated as opposed to a solid contiguously declared color.

If you want to customize the default themes of the Primefaces components with your own stylesheets then you are best to look into a tool like Firebug, https://addons.mozilla.org/en-US/firefox/addon/firebug/ for inspecting classes, styles and modifying them real time on ANY web page that Firefox is currently viewing. It even has built in Javascript debugging.