On child hover change the css of Parent

Question

I want to change the css of parent on hover of Child element.

<ul id="main-menu">
        <li>
            <a href="#">
                <i class="fa fa-building-o" aria-hidden="true"></i>
                Private Limited
                <i class="fa fa-caret-down"></i>
            </a>
            <ul class="submenu">
                <li><a href="#0">Company</a></li>
                <li><a href="#0">Contact</a></li>
                <li><a href="#0">Industry</a></li>
            </ul>
        </li></ ul>

What i want is if i hover on li of submenu, li of main-menu get highlighted.

Answer 1

As already mentioned there is no parent selector but if you recognise that you are already hovering over the parent you can achieve what you want.

A rough example:

#main-menu > li:hover > a
{
  background-color: #F00;
}

#main-menu >  li > .submenu > li:hover
{
  background-color:#00F;
}

<ul id="main-menu">
  <li>
    <a href="#">
      <i class="fa fa-building-o" aria-hidden="true"></i>
      Private Limited
      <i class="fa fa-caret-down"></i>
    </a>
    <ul class="submenu">
      <li><a href="#0">Company</a>
      </li>
      <li><a href="#0">Contact</a>
      </li>
      <li><a href="#0">Industry</a>
      </li>
    </ul>
  </li>
</ul>