如何在MDDropdownMenu中调整文本大小？(kivymd、python)

from kivymd.app import MDApp
from kivymd.uix.menu import MDDropdownMenu
from kivymd.uix.button import MDFlatButton

class MyApp(MDApp):
    def build(self):
        # 创建一个按钮作为触发下拉菜单的控件
        button = MDFlatButton(text="Dropdown Menu", pos_hint={"center_x": 0.5, "center_y": 0.5})
        button.bind(on_release=self.show_dropdown_menu)
        return button

    def show_dropdown_menu(self, button):
        # 创建下拉菜单的选项
        items = [
            {"text": "Option 1"},
            {"text": "Option 2"},
            {"text": "Option 3"}
        ]
        
        # 创建下拉菜单
        dropdown_menu = MDDropdownMenu(
            caller=button,
            items=items,
            width_mult=4,
            callback=self.dropdown_menu_callback
        )
        
        # 设置选项的文本大小
        for item in dropdown_menu.items:
            item.theme_text_color = "Secondary"
            item.font_style = "Button"
        
        # 打开下拉菜单
        dropdown_menu.open()

    def dropdown_menu_callback(self, instance):
        print(instance.text)

if __name__ == "__main__":
    MyApp().run()