<div class="outer-container">
  <div class="inner-container">
    <div class="item">1</div>
    <div class="item">2</div>
  </div>
  <div class="inner-container">
    <div class="item">3</div>
    <div class="item">4</div>
  </div>
</div>

.outer-container {
  display: flex;
  justify-content: space-between;
}

.inner-container {
  display: flex;
}

.item {
  margin: 10px;
  padding: 20px;
  background-color: #f0f0f0;
  text-align: center;
}