@media screen and (max-width: 767px) {
  .module_layout-4column.highlight .module_layout-4column__cell,
  .module_layout-4column.highlight .module_layout-4column__3cell {
    margin-top: 20px;
    float: none;
    width: 100%;
  }
  .module_layout-4column.highlight>:nth-child(2) {
    margin-top: 20px
  }
}