.grd {
  display: -ms-grid;
  display: grid;
  gap: 30px;  
}
.grd3-33-33-33 {
  grid-template-columns: repeat(1, 1fr);
}
@media screen and (min-width: 48em) {
  .grd3-33-33-33 {
    grid-template-columns: repeat(3, 1fr);
  }
}