Building a Credit Card Form Custom Element with Polymer

HTML & CSS
2

Surely this is a typo?

if(isValidNum || isValidExp || isValidCVC)
/* Success /
else
/ Validation failed */

Wouldn’t you want all the be valid, not just one of them?

if(isValidNum && isValidExp && isValidCVC)
/* Success /
else
/ Validation failed */

Otherwise, great article! Was a good read.