simple image css for gateway in pmpro

So I use membership program and I wanted to add images next to the radio button when they check out.

https://www.steveperryfanclub.org/membership-account/membership-checkout/?level=2

so i contact them on how to do it and they send me this….

.pmpro-checkout #pmpro_payment_method span {
display: inline-block;
}
.pmpro-checkout #pmpro_payment_method span a {
background-position: bottom left;
background-repeat: no-repeat;
background-size: contain;
border: none;
display: inline-block;
font-size: 16px;
font-size: 1.6rem;
padding-bottom: 80px;
width: 90%;
}
.pmpro-checkout span.gateway_authorizenet,
.pmpro-checkout span.gateway_braintree,
.pmpro-checkout span.gateway_cybersource,
.pmpro-checkout span.gateway_paypal,
.pmpro-checkout span.gateway_stripe,
.pmpro-checkout span.gateway_twocheckout {
width: 60%;
}
.pmpro-checkout span.gateway_paypalexpress {
width: 35%;
}
.pmpro-checkout span.gateway_authorizenet a,
.pmpro-checkout span.gateway_braintree a,
.pmpro-checkout span.gateway_cybersource a,
.pmpro-checkout span.gateway_paypal a,
.pmpro-checkout span.gateway_stripe a,
.pmpro-checkout span.gateway_twocheckout a {
background-image: url(../images/cc-horizontal.jpg);
}
.pmpro-checkout span.gateway_paypalexpress a {
background-image: url(../images/paypal.jpg);
}

@media (max-width:768px) {
.pmpro-checkout #pmpro_payment_method span {display: block; width: 100%; }
}

ok so it changes everything and makes it all larger. I just wanted to add a credit card icon and paypal icon to the left of the respected radio button