Bind TextArea's font size to current Scene's width using JavaFX

Question

I want a TextArea's font-size to increase or decrease depending on the width property of the Scene it's in. But I don't want the font-size to grow beyond 16px or shrink beyond 10px.

I found this older post that has the code for making TextArea's font-size grow and shrink from being binded to the Scene's width property but I'm not sure how to add the conditional Bindings for the functionality I want.

This is the code from that post which suits my needs:

import javafx.application.Application;
import javafx.beans.binding.Bindings;
import javafx.beans.property.DoubleProperty;
import javafx.beans.property.IntegerProperty;
import javafx.beans.property.SimpleDoubleProperty;
import javafx.beans.property.SimpleIntegerProperty;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.Label;
import javafx.scene.control.TextArea;
import javafx.scene.layout.HBox;
import javafx.scene.layout.VBox;
import javafx.stage.Stage;

public class FontBind extends Application {

    private DoubleProperty fontSize = new SimpleDoubleProperty(10);
    private IntegerProperty blues = new SimpleIntegerProperty(50);

    @Override
    public void start(Stage primaryStage) {
        Button btn = new Button("click me, I change color");
        btn.setOnAction((evt)->{blues.set(blues.get()+20);});//max?
        Label lbl = new Label("I'm a label");
        TextArea ta = new TextArea("Lots of text can be typed\nand even number 1234567890");
        HBox hbox = new HBox(new Label("I never change"));
        VBox child = new VBox(btn, lbl, ta);
        VBox root = new VBox(child, hbox);
        Scene scene = new Scene(root, 300, 250);

        fontSize.bind(scene.widthProperty().add(scene.heightProperty()).divide(50));
        child.styleProperty().bind(Bindings.concat("-fx-font-size: ", fontSize.asString(), ";"
                                                  ,"-fx-base: rgb(100,100,",blues.asString(),");"));

        primaryStage.setTitle("Hello World!");
        primaryStage.setScene(scene);
        primaryStage.show();
    }

    public static void main(String[] args) {
        launch(args);
    }

}

Any help would be very much appreciated. I really want to learn more about using Bindings but I'm having trouble understanding how to implement the Bindings methods