Like Daniel already explained to you, desktop applications are completely different in the code. In your case, you've used Python to code and Glade to design the window of your application.
Python as the programming language can't be used in websites, and your applications GUI is made in Glade, which means it's GTK based XML file. Websites use HTML + CSS to make things visible to you. Lets say their "GUI" is made in the combination of those two, which aren't the same as XML files native desktop applications are using.