.product-grid {
  grid-auto-flow: dense;
}

@media screen and (max-width: 749px) {
  .product-grid__item--collection-banner {
    grid-column: 1/-1;
  }
}

@media screen and (width > 750px) {
  .product-grid__item {
    grid-column-end: span var(--column-width);
    grid-row-end: span var(--column-height);
  }
}