JSFiddle - React, Tailwind, and code Playground

HTML

<ul id="cont">
<li class="myclass"><a>1</a></li>
<li class="myclass"><a>2</a></li>
<li class="myclass"><a>3</a></li>
<li class="myclass"><a>4</a></li>
<li class="myclass"><a>5</a></li>
</ul>

CSS

#cont li{ float:left; width:15px; padding:5px; border:1px solid red; margin:5px;}       

#cont li a:hover,.active{ background-color:yellow;}

JavaScript

jQuery(function(){

  jQuery(document.body).on('mouseenter','.myclass',function() {
    
     
    jQuery(this).next('.myclass').addClass('active');
       
      
    }); 
    
    
});