Not all text properties change.

Hi @ildomandatore,

Happy to clarify.

The credit card fields (card number, cvc, expiration date), and the IBAN field are loaded directly from the payment gateway via an iframe so it’s not possible to customize them via CSS or otherwise.

We have a guide for customizing the Stripe credit card fields here: https://givewp.com/documentation/add-ons/stripe-gateway/styling-stripe-elements-cc-fields/

The IBAN field cannot be customized at all.

A pity, it will be a job for future developers.