.product_options_radio input[type=radio]{
    display:none;
}

.product_options_radio label:hover{
    cursor:pointer;
    background-color:#EEEEEE;
}
.product_options_radio label{
    display:inline-block;
    padding:8px;
}
.product_options_radio label.selected{
    background-color:#000000;
    color:#FFFFFF;
}