Besides the issues of the OP approach that many point out on this thread, I also want to point out that the ZIP code input on the example, doesn't have the type

Besides the issues of the OP approach that many point out on this thread, I also want to point out that the ZIP code input on the example, doesn't have the type=number so my mobile keyboard opens with the whole keys instead of the numeric keyboard, in this case that ZIP codes are only numbers, the type=number will improve accessibility.