import UI.MainWindow; import javax.swing.*; import java.awt.*; public class Main { public static void main(String[] args) { try { UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName()); } catch (UnsupportedLookAndFeelException | ClassNotFoundException | InstantiationException | IllegalAccessException _) { } EventQueue.invokeLater(() -> { MainWindow w = new UI.MainWindow(); w.setVisible(true); }); } }