I have a button with several style classes, "toggle-button", plus "a", "b" and "c".
This css works:
.a .b { -fx-base: white; }
But this doesn't:
.a .b .c { -fx-base: white; }

I can't find any documentation about using more than two selectors; the closest is http://docs.oracle.com/javafx/2/css_tutorial/jfxpub-css_tutorial.htm
But I would expect to combine an arbitrary number of selectors.