We do not store your credit card info in our own database and we do not send any credit card information to our servers.
We use a payments platform service called Stripe to process and store our customer credit card data. https://stripe.com. Stripe is widely used in many companies and is secure: https://stripe.com/us/customers
Stripe does not allow customers to use a non-secure connection.
General Security Tips
Make sure you never enter your credit card info on a computer shared with somebody else or on an unprotected wireless network such as public wifi at an airport.
We also recommend you never enter your card information in any website while in a public setting as someone could view it on your screen in a public place.