Adjust mobile zooming to personal liking

Dear community, I think about switching to Fotografie theme but I am not satisfied with the default zooming options on mobile view. Is there a way to easily tamper with the mobile zooming functionality, e.g. allow 200% zoom in, with custom css? Any help is much appreciated, thanks + regards Florian PS y’all have a wonderful xmas 😉 The page I need help with: http://www.infinite-colours.com