HTML,CS and JS newbie challenge - CTA page

By trying this "simple" challenge I realize how much more I need to learn. I think there is a lot of mistakes in my code that could have been completed far more easily than I have done.

For example when I was trying to do fullsize windows - from edge to edge, the aspect ratio for the image on the right wasnt right. only the top half could be seen. When I changed the dimensions a bit, the card wasnt centered. In the end I put max-width 75% that sort of solved it, but i am not happy with it.

I will be happy for any feedback.