I run into a problem. The interaction works well the first time I try it. Then when I change tab and comeback to a previous tab, the size of the tab seems to get really big before getting to right size and it create and animation wierdness.
In the tab-inactive animation. The parameters of the action that changes the tab-link description width should be set to “–” px and not “0” px. Wierd but it fixed the problem for me.