<div class="grid">
  <div class="nested">
    <div>a</div>
    <div>b</div>
    <div>c</div>
  </div>
  <div>2.</div>
  <div>3.</div>
</div>

* { box-sizing: border-box; }

body {
  margin: 40px;
  background-color: #fff;
  color: #444;
  font: 1.4em Sansita, sans-serif;
}


.grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  grid-gap: 20px;
}

.grid .nested {
  display: grid;
  grid-gap: 10px;
  grid-template-columns: repeat(2, 1fr);
}

.nested > * {
  border: 5px solid rgb(244,234,213);
  padding: 20px;
  border-radius: 5px;
  background-color: rgb(198,229,217);
  color: #000;
}

.grid > * {
padding: 10px;
  border: 5px solid rgba(214,129,137,.5);
  border-radius: 5px;
  background-color: rgba(233,78,119,.5);
  color: #fff; 
}