<div class="container">
  <div class="item">
    A cool container item
  </div>
</div>

.container {
  container-type: inline-size;
  max-width: 800px;
  width: 100%;
  text-align: center;
  border: 2px dotted #695958;
}

.item {
  background: #271f30;
  color: white;
  margin: 5cqw;
}