Style application

src/main/java/app/Main.java

@@ -42,6 +42,9 @@ public class Main extends Application {
     }
 
     Scene scene = new Scene(document);
+
+    scene.getStylesheets().add(getClass().getResource("/styling/app.css").toExternalForm());
+
     window.setScene(scene);
     window.show();
   }