Pane size is different

public class Application extends javafx.application.Application {
    @Override
    public void start(Stage stage) throws IOException {
        Parent root = FXMLLoader.load(Objects.requireNonNull(getClass().getResource("Scene1.fxml")));
        Scene scene = new Scene(root, 1000, 600);
        stage.setTitle("App");
        String css = Objects.requireNonNull(getClass().getResource("/com/example/javafx/style1.css")).toExternalForm();
        scene.getStylesheets().add(css);
        stage.setScene(scene);
        stage.show();
    }

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