<div class="grid">
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
</div>

.item {
  background-color: tomato;
}

.grid {
  display: grid;
  grid-template-columns: repeat(6, 50px);
  grid-auto-rows: 100px;
  gap: 8px;
}

.grid .item {
  grid-column: span 2;
}

.grid .item:first-child, .grid .item:nth-child(2) {
  grid-column: span 3
}