.layout--ems-header-twocol {
  display: flex;
  flex-wrap: wrap;
}

.layout--ems-header-twocol > .layout__region {
  flex: 0 1 100%;
}

@media screen and (min-width: 40em) {
  .layout--ems-header-twocol > .layout__region--first,
  .layout--ems-header-twocol > .layout__region--second {
    flex: 0 1 50%;
  }
}