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

.container {
  display: flex;
  justify-content: center;
}

.item {
  padding: 100px;
  background-color: aqua;
  margin-right: 15px;
}