Javafx 2.0 : How to change the size of the radio-buttons circle with CSS?

I try to change the radio-buttons size in my app build with FXML and CSS. I use the sceneBuilder.

Thanks for your help !

Here is my actual CSS code for the radio-buttons :

.radio-button .radio{
-fx-border-width     : 1px   ;
-fx-border-color     : #000  ;
-fx-background-color : white ;
-fx-background-image : null  ;
-fx-border-radius    : 15px  ;
-fx-height           : 15px  ; /* Not working */
height               : 5px   ; /* Not working */
}
.radio-button .radio:selected{
-fx-background-color : white ;
-fx-background-image : null  ;
}
.radio-button -radio:armed{
-fx-background-color : white ;
-fx-background-image : null  ;
}
.radio-button -radio:determinate{
-fx-background-color : white ;
-fx-background-image : null  ;
}
.radio-button -radio:indeterminate{
-fx-background-color : white ;
-fx-background-image : null  ;
}