Requirements: effects extension
In this example, carouhell is turned on only on small screen below 600px width. The effects extension creates a hidden div classed css after the carouhell which can be accessed via .carouhell+.css selector. There you are expected to set its media rule opacity: when the opacity changes, 1ms transitionend event is fired and, if provided, mediaCSS(o) method is executed, where o is 10 times the current opacity as Integer (here, opacity 0.6 yields to 6). This is for safe and convenient comparison (you can't safely write if(o==0.6)).