KVin, change your CSS class to be this so that it is saying “within the .paymentMethod field, change the css of all .nx-radiowrapper areas to be something different”
.paymentMethod .nx-radiowrapper {
display: inline-block;
min-width: 11em;
}
I’d adjust the min-width to get it to be wide enough to fit the full picklist value on one line.