<div class="container">
  <ul>
    <li>1つ目のP要素</li>
    <li>2つ目のP要素</li>
    <li>3つ目のP要素</li>
    <li>4つ目のP要素</li>
    <li>5つ目のP要素</li>
  </ul>  
</div>

.container ul li:nth-child(3) {
  color: red;
}

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External JavaScript

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