.salesku_plugin-product ul.skus li {
    margin-right: 10px;
    margin-bottom: 10px;
}

.options__buttons-link {
   
}
.options__buttons-item input {
    display: none;
}
.options__buttons-item input:checked + span {
   font-weight: bold;
   -webkit-box-shadow: 0 0 0 2px #ff3a3a;
    box-shadow: 0 0 0 2px #ff3a3a;
    color: #000;
}