private void bunifuFlatButton1_Click_2(object sender, EventArgs e)
        {
            if (Application.OpenForms.OfType <Settings_NB>().Count() == 1)
            {
                Application.OpenForms.OfType <Settings_NB>().First().Close();
            }

            Settings_NB frm = new Settings_NB();

            frm.Show();
        }
        private void bunifuFlatButton1_Click(object sender, EventArgs e)
        {
            Settings_NB set = new Settings_NB();

            set.Show();
        }