.credit-card {
    display:inline-block; 
    height:3.2rem; 
    width:4.8rem; 
}

.american-express {
    background:url(//cdn.intustech.com/eAssociate/assets/images/american-express-straight-32px.png) no-repeat 0 0; 
}
.discover {
    background:url(//cdn.intustech.com/eAssociate/assets/images/discover-straight-32px.png) no-repeat 0 0; 
}
.mastercard {
    background:url(//cdn.intustech.com/eAssociate/assets/images/mastercard-straight-32px.png) no-repeat 0 0; 
}
.visa {
    background: url(//cdn.intustech.com/eAssociate/assets/images/visa-straight-32px.png) no-repeat 0 0;
}