#nav li.four_columns ul.sub-menu {
  width: 600px;
  display: flex;
  -webkit-flex-direction: column;
  flex-direction: column;
  justify-content: flex-start;
  align-items: flex-start;
  flex-flow: wrap;
}

#nav li.four_columns ul.sub-menu li {
  flex-basis: 25%;
  /* white-space: nowrap; */
  /* overflow: hidden; */
  /* text-overflow: ellipsis; */
  /* border-bottom: none; */
}