JavaFX窗口大小小于SceneBuilder

import javafx.application.Application;
import javafx.fxml.FXMLLoader;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.stage.Stage;

public class MainApp extends Application {
    @Override
    public void start(Stage primaryStage) throws Exception {
        Parent root = FXMLLoader.load(getClass().getResource("sample.fxml"));
        primaryStage.setTitle("Hello World");
        primaryStage.setScene(new Scene(root, 800, 600)); // 设置窗口大小
        primaryStage.show();
    }

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

.root {
    -fx-min-width: 800px;
    -fx-min-height: 600px;
}

Scene scene = new Scene(root);
scene.getStylesheets().add(getClass().getResource("styles.css").toExternalForm());
primaryStage.setScene(scene);

try {
    Parent root = FXMLLoader.load(getClass().getResource("sample.fxml"));
    primaryStage.setScene(new Scene(root));
    primaryStage.show();
} catch (IOException e) {
    e.printStackTrace();
}