take-class
Syntax
take-class: (class) [every (time)] [after (time)][, (class)...];
time = Time in standard CSS time format, eg. 1s = 1 second, 250ms = 250 milliseconds.
This command removes the class specified from any elements or nodes in the target selector's document that have it set in their class attribute, and then adds the specified class to the target selector. The effect is to "take" the class from any other element or elements that have it.
The following example will take the "menuSelected" class from any other elements that may already have the "menuSelected" class, and assign the class to the element clicked (which is a menu button that shares the class "menuItem" with other menu buttons):
.menuItem:click {
take-class: .menuSelected;
}