<div class="list">
  <p>変わりません</p>
  <p>変わりません</p>
  <p>3番目の要素が赤色に変わります。</p>
  <p>変わりません</p>
  <p>変わりません</p>
</div>
.list p:nth-child(3) {
  color: #f00;
}

External CSS

This Pen doesn't use any external CSS resources.

External JavaScript

This Pen doesn't use any external JavaScript resources.