JSFiddle - React, Tailwind, and code Playground

HTML

<div class="parent">
 <div class="enfant">
   <p>
   A gagner
   </p>
   <ul>
     <li>Un voyage</li>
     <li>Un Vodada</li>
     <li>ububibi</li>
   </ul>
 </div>
  <div class="enfant">
   <p>
   A gagner
   </p>
   <ul>
     <li>Un voyage</li>
     <li>Un Vodada</li>
     <li>ububibi</li>
   </ul>
 </div> 
</div>

CSS

div{
  border: 1px solid green;
}

.parent{
  display: flex;
 
}

.enfant{
  display: inherit;
  flex-grow: 1;
}