.js-form-type-datelist {
    width: 50%;
}
.js-form-type-datelist .js-form-type-select {
    width: calc(50% - 15px);
    display: inline-block;
    margin-right: 15px;
}
@media screen and (max-width:991px) {
  .js-form-type-datelist {
    width: 100%;
  }
}