Interactive card details form w/ Dark mode

😌Finally, I have completed this project, and I have a question for the community. How can I detect when a input field with the attribute type number is empty, and the user inputs non-numeric characters in JavaScript? I needed this information to show different errors at different states. Although I tried to find a solution, I couldn't do it, so I used the text attribute type for the card number, expiration date, and CVC input fields instead.

Thanks in advance!👍