import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.control.TextField;
import javafx.scene.layout.HBox;
import javafx.stage.Stage;

public class Main extends Application {    
    public static void main(String[] args) {
        launch(args);        
    }
    
    @Override
    public void start(final Stage stage) {        
        HBox root = new HBox();
        final Scene scene = new Scene(root);
        stage.setWidth(600);
        stage.setHeight(200);
        stage.setScene(scene);        
        
        String cssPath = "/test.css";
        scene.getStylesheets().addAll(cssPath);
        
        TextField tf = new TextField("Hello world");
        tf.setStyle("-fx-background-color: pink;");
        
        root.getChildren().addAll(tf);
        
        stage.setVisible(true);
    }
}