<div class="parent">
  <div class="box"></div>
  <div class="box"></div>
  <div class="box"></div>
</div>
.parent{
  width: 100%;
  background-color: #e5e5e5;
  display: flex;
}

.box{
  width: 50px;
  height: 50px;
  background-color: #333;
  margin:10px;
}

External CSS

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External JavaScript

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