View source for Main-ui (CSS pseudo selector)

PowerUI defines main-ui (and [[World-ui (CSS pseudo selector)|world-ui]]) to make distinguishing the two within CSS easy. For example, PowerUI's [[User agent stylesheet]] uses it to make sure the main UI has a slightly larger font size by default.

<syntaxhighlight lang="css">

/* Target the body of the main UI */

body:main-ui{
 
 color:red;
 
}

</syntaxhighlight>

This pseudo-selector is true when:

* The element is on the main UI only (in UI.document)
* The main UI is navigated to a resources:// file