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

.container {
  display: flex; /* Enables Flexbox */
  background-color: #f0f0f0; 
  border: 2px solid #ccc; 
  height: 100px;*/
  padding: 10px; 
}

/* Child items */
.flex-item {
  background-color: #4caf50; 
  color: white;
  padding: 20px; 
  margin: 5px; 
  text-align: center; 
}