JavaFx - dsenhando elipse com preenchimento via css

Veja abaixo uma imagem do programa em execução:

Veja abaixo o código do programa:

import javafx.application.Application;

import javafx.scene.Scene;

import javafx.scene.canvas.Canvas;

import javafx.scene.canvas.GraphicsContext;

import javafx.scene.layout.Pane;

import javafx.scene.paint.Color;

import javafx.scene.text.Font;

import javafx.scene.text.FontPosture;

import javafx.scene.text.FontWeight;

import javafx.stage.Stage;

public class PROJETO extends Application {

     Pane root_1 = new Pane ( );

     Pane root_2 = new Pane ( );

     Scene scene = new Scene ( root_1, 600, 310 );

     Canvas canvas = new Canvas ( 600, 310 );

     GraphicsContext ctx = canvas.getGraphicsContext2D ( );

    // /////////////////////////////////////////////////////////////////////////

   public void Informe ( ) {

       ctx.setFont ( Font.font ( "Helvetica", FontWeight.NORMAL,

                 FontPosture.ITALIC, 14 ) );

       ctx.setFill ( Color.RED );

       ctx.fillText ( "Por: ", 250, 225 );

       ctx.setFill ( Color.BLUE );

       ctx.fillText ( "Samuel Lima", 280, 225 );

       ctx.setFill ( Color.BLACK );

       ctx.fillText ( "sa_sp10@hotmail.com", 250, 240 );

       ctx.setFill ( Color.RED );

       ctx.fillText ( "MUITO OBRIGADO", 250, 280 );

   }

   // //////////////////////////////////////////////////////////////////////////

     @Override

     public void start ( Stage stage ) {

         stage.setTitle ( "JAVAFX - DESENHANDO COM CSS" );

         // Usando fonte em italic

         ctx.setFont ( Font.font ( "Helvetica", FontWeight.NORMAL,

                   FontPosture.ITALIC, 17 ) );

        ctx.setFill ( Color.RED );

       ctx.fillText ( "JAVAFX - ELIPSE COM PREENCHIMENTO VIA CSS", 110, 40 );

         root_2.setStyle (

                   "-fx-padding: 140 285;"

                            + "-fx-border-width: 10;"

                            + "-fx-border-height: 10;" 

                            + "-fx-border-insets: 5;"

                            + "-fx-border-radius: 5;"

                            + "-fx-border-color: #300000;"      

                   );

         // Criando uma elipse com css

         root_1.setStyle ( "-fx-background-color:"

                   + " radial-gradient( center 50% 40%,"

                   + " radius 25%, blue 50%, white 50% );"

         );

         Informe ( );

         root_1.getChildren ( ).addAll ( root_2, canvas );

         stage.setScene ( scene );

         stage.show ( );

     }

     // /////////////////////////////////////////////////////////////////////////

     public static void main ( String [ ] args ) {

         launch ( args );

     }

}