Interactive credit card details

During this project i started learning about patterns, pattern validation and regex, it was a fun project, i also struggled a bit with the layout of the page and the responsive look for mobile, but i think i manage to work it out and made it look good in general, the js script was not as hard but again i'm not sure if i overcomplicated myself and could have used a better approach to it, then again, the most important part is that it works. In general I'm satisfied with the results, any feed back is very welcome :)