<nav>
  <div class="dropdown">
    <details>
      <summary>
        <svg height="20" viewBox="0 0 20 20" xmlns="http://www.w3.org/2000/svg">
          <path d="M0 3h20v2H0V3zm0 6h20v2H0V9zm0 6h20v2H0v-2z" fill="white"/>
        </svg>
      </summary>
      
      <ul>
        <li>Profile</li>
        <li>Settings</li>
        <li>Sign out</li>
      </ul>
    </details>
  </div>
</nav>

<p>
  Other content below the navigation bar
</p>

nav {
  padding: 1.2em;
  background-color: #8259a8;
  color: white;
}

.dropdown ul {
  background-color: white;
  color: #8259a8;
}