JSFiddle - React, Tailwind, and code Playground

HTML

<div class="wrap">
          <div class="blok"></div>
</div>

CSS

.wrap{
margin:20px auto;
width:600px;
background:#e7e7e7;
padding:20px 0px;    
}

.blok{
margin:0 auto;
width:200px;
height:200px;
background:#e7e7e7;
border:1px solid #ccc;
box-shadow:inset 0px 0px 0px 1px #fff;
-moz-box-shadow:inset 0px 0px 0px 1px #fff; 
-webkit-box-shadow:inset 0px 0px 0px 1px #fff;    
}