Vaadin Sampler animation HOW-TO

From what I’ve read, the Vaadin Sampler source code is not available at the moment. However, the Sampler contains multiple instances of CSS animations which I’ve been, honestly, struggling to get right with Vaadin. The most notable is the “book animation” when you click on the top right icon - it both hides the right component AND expands the width of the left component at the same time.

​Properly reacting to component width changes is something that I have not been able to achieve. For example, I did a slider animation for my component - only for the other component attached to it stay still while the animation progressed. Generally, from what I understand, width change animations are not supported by the framework at all as long as you want proper layouting since the server-side is not informed about the width change.

​It would be nice if at least the animation code snippets for Sampler were published. Or maybe some proper tutorial about how to combine CSS animations with Vaadin code.