JSFiddle - React, Tailwind, and code Playground

HTML

<div class='a'>
    </div>
    
<div class='b'>
    </div>

CSS

.a {
    width:66%;
    height:100px; 
    margin-top:10px;
    margin-bottom:10px;
    margin-right:auto;
    margin-left:10px;
    border: 1px solid black; 
    background-color: #fefd8f;
    }
        
.b  {
      width:66%;
      height:100px; 
      margin-top:10px;
      margin-bottom:10px;
      margin-right:10px;
      margin-left:auto;
      height:100px;         
      border:1px solid black; 
      background-color:#f6ccfc;
      }