Not directly programming or coding GUI from scratch with a library or something: Have you considered using a game engine like Godot ( https://godotengine.org/ ) ?
You would have a toolbox for several essential GUI-elements. You could visually create the GUI and add functionality by script. Also, there are several possibilities to handle different screen sizes and touch.
You would have to learn the UI and concepts of Godot but the documentation is ok and there are plenty of tutorials available.
Not directly programming or coding GUI from scratch with a library or something: Have you considered using a game engine like Godot ( https://godotengine.org/ ) ?
You would have a toolbox for several essential GUI-elements. You could visually create the GUI and add functionality by script. Also, there are several possibilities to handle different screen sizes and touch.
You would have to learn the UI and concepts of Godot but the documentation is ok and there are plenty of tutorials available.