/* Incluye los de form-control, que pierde la clase */
form #card_number {
    background-image: url(https://jquerycreditcardvalidator.com/images/images.png), url(https://jquerycreditcardvalidator.com/images/images.png);
    background-position: 2px -121px, 260px -61px;
    background-size: 120px 361px, 120px 361px;
    background-repeat: no-repeat;
    padding-left: 54px;
    height: 36px;
    padding-top: 12px;
    padding-right: 12px;
    padding-bottom: 12px;
    border: #c6c6c6 1px solid;
    -webkit-border-radius: 6px;
    -moz-border-radius: 6px;
    border-radius: 6px;
    -webkit-box-shadow: none;
    -moz-box-shadow: none;
    box-shadow: none;
    display: block;
    width: 100%;
}
form #card_number.visa {
    background-position: 2px -163px, 260px -61px;
}
form #card_number.visa_electron {
    background-position: 2px -205px, 260px -61px;
}
form #card_number.mastercard {
    background-position: 2px -247px, 260px -61px;
}
form #card_number.maestro {
    background-position: 2px -289px, 260px -61px;
}
form #card_number.discover {
    background-position: 2px -331px, 260px -61px;
}
form #card_number.valid.visa {
    background-position: 2px -163px, 260px -87px;
}
form #card_number.valid.visa_electron {
    background-position: 2px -205px, 260px -87px;
}
form #card_number.valid.mastercard {
    background-position: 2px -247px, 260px -87px;
}
form #card_number.valid.maestro {
    background-position: 2px -289px, 260px -87px;
}
form #card_number.valid.discover {
    background-position: 2px -331px, 260px -87px;
}