So, basically, you have a main css class with "transition-duration: 1.5s;", another class with left: -275px; and after you change to a class with left: 0px; and it animates itself without javascript (it is used only to change classes).<p>That's cool, exited about new CSS features, wish they did added these earlier..<p>And it reminds me a bit about Adobe Flash IDE, you can do animations without actionscript just by using their IDE.