JSFiddle - React, Tailwind, and code Playground

HTML

<div class="container">
     <ul class="one">
       <li> <span>a</span> a </li>
       <li> <span>b</span> b </li>    
     </ul>
     
      <ul  class="two">
       <li> <span>a</span>  a  </li>
       <li> <span>b</span> b </li>    
     </ul> 
</div>

CSS

.one {
    background-color: blue;
    width: 150px;
    height: 150px;
    float: left;
}
.two {
    background-color: red;
    width: 150px;
    height: 150px;
    float: left;
    margin-left: 100px;
}
.one {color: #fff}
.two {color: #fff}
.container:hover ul li:nth-child(span){
    background: yellow;
}