Amazing site... how is it done!?

I recently discovered . It is an extremely awesome site with an Instant Messenger (that translates virtually any language) and when you click on the menu items it resizes, even when multiple items are clicked (if you explore the site u will know what I mean). Does anyone know how to make the menu items resize, even when multiple items are expanded? I know you could probably use an ton of If Then statments but when one item is changed, If Then statments would set back the menu item to the default. I think they used some other techinique that I am trying to figure out. Any ideas? And I know the instant messenger this is probably to advanced for any member of this board but if anyone has any ideas, please let me know. Thanks.