Animations need Java code to be defined and enabled for properties in JavaFX. While is is working and produces great results, in fact the role separation is void: Designers cannot speak Java, and they don't want to recompile an application just to get animated views.

Hence our proposal is to add a proprietary syntax to CSS. The syntax allows to specify either...
...a static value, just as it is right now
   (like -fx-opacity: 0.6)
...the name of an animation class, which is to be used to animate the property
   (like -fx-opacity: foo.bar.MyFader)
...a constructor syntax for animation classes, allowing to provide customization parameters
   (like -fx-opacity: foo.bar.MyFader(0.1, 0.3))

This syntactical extension allows a designer most flexibility, and even enables the existing JavaFX 8 animations like FadeTransition to be used out of the box by any CSS aware artist.