CodePen Embed - :nth-child(2) counts any element with spans?

<h1>
  Hidd<span>e</span>n
  <br>
  Br<span>a</span>in
</h1>

span:nth-child(3) {
  background: #f8a100;
  display: inline-block;
  width: 50px;
}

This Pen is owned by Geoff Graham on CodePen.

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