For Source Code, You have to View the Source of demo Page and look for .CSS File. If not let us know in comments below 🙂
Flip Drop Down menu has 3D unfolding sub list with animation. Just hover the top level link to see this in IE10, Firefox, Safari and Chrome.
Earlier versions of IE will see an instant sub menu list
This uses a mixture of transitions and keyframe animation. The last sub menu item is animated on hover by using a keyframe to give it a small amount of ‘bounce’ but is closed when the mouse is moved off the menu by using a transition. All other sub menu items are animated using just transitions.