JSFiddle - React, Tailwind, and code Playground

HTML

<ul id="accordion" class="accordion">
  <li>
    <div class="link">Menu 2</div>
    <ul class="submenu">
      <li><a href="#">submenu1</a></li>
      <li><a href="#">submenu1</a></li>
      <li><a href="#">submenu1</a></li>
    </ul>
  </li>
  <li>
    <div class="link">Menu 3</div>
    <ul class="submenu">
      <li><a href="#">submenu1</a></li>
      <li><a href="#">submenu1</a></li>
      <li><a href="#">submenu1</a></li>
    </ul>
  </li>
</ul>

CSS

.accordion {
  width: 100%;
  max-width: 260px;
  background: #FFF;
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

.accordion .link {
  cursor: pointer;
  display: block;
  padding: 15px 15px 15px 42px;
  font-size: 14px;
  font-weight: 700;
  border-top: 1px solid #CCC;
  border-bottom: 1px solid #CCC;
  border-right: 1px solid #CCC;
  position: relative;
  -webkit-transition: all 0.4s ease;
  -o-transition: all 0.4s ease;
  transition: all 0.4s ease;
}


/*-------------Submenu-----------------------------*/

.submenu {
  padding: 0px;
  display: none;
  font-size: 14px;
}

.submenu li {
  border-bottom: 1px solid #4b4a5e;
}

.submenu a {
  display: block;
  text-decoration: none;
  color: #23222d;
  background-color: #CCC;
  padding: 12px;
  padding-left: 42px;
  -webkit-transition: all 0.25s ease;
  -o-transition: all 0.25s ease;
  transition: all 0.25s ease;
}

.submenu a:hover {
  background: #b63b4d;
  color: #FFF;
}

a.active {
  background: #b63b4d;
  color: #FFF;
}

JavaScript

$(document).ready(function() {
 
   $("#accordion > li > div").click(function() {
     if (!$(this).next().is(":visible")) {
       $(this).next().slideDown();
     } else {
       $(this).next().slideUp();
     }
   });
   
   $(".submenu a").click(function() {
     		$(this).toggleClass("active").parent().siblings().find("a").removeClass("active");
   });
   
 });