2col grid

HTML

<div class="boxes">
  <div class="bigbox">1</div>
  <div class="smallbox">2</div>
  <div class="smallbox">3</div>
  <div class="smallbox">4</div>
  <div class="smallbox">5</div>
</div>

SCSS

.boxes {
  display: grid;
  grid-template-columns: 1fr 1fr;
  grid-column-gap: 25px;
  grid-row-gap: 25px;
}

.smallbox {
  border: 2px solid black;
  padding: 1em;
  height: 50px;
}

.bigbox {
  border: 1px solid black;
  padding: 1em;
  background: red;
  height: 150px;
}