After your last comment I tried again and… then I opened usual view of CodePen on mobile and click to Full Page View than it become not responsive.
Is it real problem with responsive or it’s just a some bug of a CodePen?
lasjorg, that is really great comment! Thank you.
I will use it if I will loose all chances to save view as in the pic in the previous reply for all users.
I am not very familiar with CodePen so I can not tell, and even when I checked the project on Chrome DevTools it is not responsive. But @lasjorg already gave you some good clues on what you should do.