If you need to change the styles of some elements using jQuery, you might use
.css(), but that applies inline styles and we generally don’t like that. You could add/remove/change a class name to control the style, which is better, but then still only works on matching elements that are currently in the DOM.
This neat mini jQuery plugin by Danny Povolotski actually injects real CSS on the page so all (even future) matching elements get that style. Kinda like event delegation for styles.