We are using international PayPal service https://www.braintreepayments.com
We do not see or store ANY of your card information. All not sensitive data come to us from Braintree service.
If you want to be SHURE, just enter something wrong in card details, one or all wrong numbers for example, and you will see an error. Only companies with direct connection to banks can check your data fast and online.
And it's Braintree job ;)
Their code directly generate window with card details fields on our site, not us.
Have a safe purchases!