[deelowe]

s/copied/used as inspiration/

Copyright means you literally copied the design. Are you maybe confusing copyright and trademark? With trademark, you can get in trouble for creating brand confusion, which has a more to do with the look and feel than the actual copy.

[dangrossman]

Copyright also grants the exclusive right to create derivative works. Using another work as the basis of your own, even with zero direct copying, can be an infringement of that right. I doubt that happened here, and proving it would be near-impossible, but we should be cognizant of what copyright actually is.