JSFiddle - React, Tailwind, and code Playground

HTML

<div class="container">
   <div> should be on the TOP</div>
   <div> should be on the BOTTOM</div>
 </div>

CSS

.container {
    display: flex;
    flex-direction: column;
    justify-content: space-between;  
    
    min-height: 150px;
    
    background-color: #cbcbcb;
}