<nav id="menu">
  <ul>
    <li>Menu 1
      <ul>
        <li>Menu 1.a</li>
        <li>Menu 1.b</li>
      </ul>
    </li>
    <li>Menu 2</li>
    <li>Menu 3</li>
  </ul>
</nav>
#menu ul ul > li {
  color: blue;
}

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External JavaScript

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