Foundation CSS is an open-source & responsive front-end framework built by ZURB foundation in September 2011, that makes it easy to design beautiful responsive websites, apps, and emails to look amazing & can be accessible to any device. It is used by many companies such as Facebook, eBay, Mozilla, Adobe, and even Disney. The framework is built on Saas-like bootstrap. It is more sophisticated, flexible, and easily customizable. It also comes with CLI, so it’s easy to use it with module bundlers. It offers the Fastclick.js tool for faster rendering on mobile devices.  

Menus are the main tools for visitors to navigate throughout a website. Foundation CSS Nested Style Menu creates the nested navigation menu. The menu items are created using <ul> and <li> elements.

Foundation CSS Menu Nested Style Class:

• nested: This class is used to create nested navigation menu. The nested navigation menu has extra padding on the element.

Syntax:

<ul class="menu">
  <li><a href="#">Item 1</a></li>
  <li>
    <a href="#">Item 2</a>
    <ul class="nested menu">
      <li><a href="#">1</a></li>
      <li><a href="#">2</a></li>
      . . .
    </ul>
  </li>
  <li><a href="#">Item 3</a></li>
  . . .
</ul>

Example:

Output:

Reference: https://get.foundation/sites/docs/menu.html#nested-style