.l-three-col {
  column-gap: 30px;
  display: grid;
  row-gap: 30px;
  grid-template-columns: repeat(23, 1fr);
}

.l-three-col__side-primary {
  grid-column: 1 / span 5;
  width: 100%;
}

.l-three-col__main {
  grid-column: 7 / span 11;
  width: 100%;
}

.l-three-col__side-secondary {
  grid-column: 19 / span 5;
  width: 100%;
}