.lp-builder .layout--threecol {
  display: flex;
}

.lp-builder .layout--threecol > .layout__region {
  flex: 0 1 100%;
}

.layout--threecol { grid-template-columns: repeat(1, minmax(0, 1fr)); }

@media screen and (min-width: 768px) {
  .lp-builder .layout--threecol > .layout__region {
    flex: 0 1 33.33333334%;
  }
  .layout--threecol { grid-template-columns: repeat(3, minmax(0, 1fr)); }
}