JSFiddle - React, Tailwind, and code Playground

HTML

<div id="mydiv">

</div>

CSS

#mydiv {
    width: 100px;
    height:100px;
    background-color: gray;  
    margin:50px 50px;
    
    -webkit-box-shadow:0 0 20px blue; 
    -moz-box-shadow: 0 0 20px blue; 
    box-shadow:0 0 20px blue;
}