if FX we current support border radius syntax like:

 -fx-border-radius: 100px 90px 80px 70px 400px 300px 200px 100px;

but the spec is

 border-radius: 100px 90px 80px 70px / 400px 300px 200px 100px;

see: http://www.w3.org/TR/css3-background/#the-border-radius