Default appeareance system

GUI.py

@@ -98,6 +98,8 @@ class App(customtkinter.CTk):
                                                         values=["Light", "Dark", "System"],
                                                         command=self.change_appearance_mode)
         self.optionmenu_1.grid(row=10, column=0, pady=0, padx=20, sticky="w")
+        # Set default mode to system
+        self.optionmenu_1.set("System")
 
 ### Adds all the stuff for frame_settings ###