It isn't providing a visual for all credit card issuers, though (eg Diner's Club, JCB). Those cards may still be processed correctly (I don't have any way of ve

It isn't providing a visual for all credit card issuers, though (eg Diner's Club, JCB). Those cards may still be processed correctly (I don't have any way of verifying), but visually treating a correct input like an invalid input isn't going to help conversion much. Easily solved by simply adding treatments for more card types, and styling the entire card isn't that much more effort than just displaying an issuer logo. Where this starts to get really interesting (from a slick + branded perspective) is when you start handling gift cards.