<div class="w300">
  <div class="w100"></div>
  <div class="w100 red"></div>
  <div class="w100"></div>
</div>

<table class="wrapper">
  <tr>
    <td class="item"></td>
    <td class="item red"></td>
    <td class="item"></td>
  </tr>
  <tr>
    <td class="item"></td>
    <td class="item red"></td>
  </tr>
</table>
.w300 {
  display: flex;
  width: 100%;
}

.w100 {
  width: 100px;
  height: 100px;
  background-color: #eee;
}

.wrapper {
  width: 300px;
  border-collapse: collapse;
}

.item {
  box-sizing: border-box;
  width: 100px;
  height: 100px;
  background-color: #eee;
  border: 5px solid #000;
}

.red {
  background-color: #f99;
}

External CSS

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External JavaScript

This Pen doesn't use any external JavaScript resources.