.product-grid {
  display: flex;
  flex-wrap: wrap;
  width: 100%;
  list-style: none;
  padding: 0;
  margin: 0 -2px;
}

.product-grid .grid_item {
  padding: 0 2px 15px;
  list-style: none;
  width: 25%;
}

@media screen and (max-width: 990px) {
  .product-grid .grid_item {
    width: 50%;
  }
}