JSFiddle - React, Tailwind, and code Playground

HTML

<ol>
  <li>item</li> 
  <li>item             
    <ul>
      <li>item</li>     
      <li>item</li>    
       <li>item</li>    
    </ul>
  </li>
  <li>item</li>        
  <li>item</li>      
  <li>item
     <ul>
      <li>item</li>      
      <li>item</li>      
      <li>item         
    </ul>
   </li>        
  <li>item</li>       
</ol>

CSS

ol{
   list-style:none;
   counter-reset: my;
}


li::before {
  counter-increment: my;
  content: counter(my) ; 
  margin-right: 10px;
}