JSFiddle - React, Tailwind, and code Playground

HTML

<div class="one"></div>

CSS

.one {
    width: 100px;
    height: 100px;
    background: red;
    -webkit-box-shadow: -1px -1px 5px rgba(50, 50, 50, 0.75);
    -moz-box-shadow:    -1px -1px 5px rgba(50, 50, 50, 0.75);
    box-shadow:         -1px -1px 5px rgba(50, 50, 50, 0.75);
    -webkit-transition: box-shadow .3s;
}

.two {
    width: 100px;
    height: 100px;
    background: red;
    -webkit-box-shadow: -1px -1px 13px rgba(50, 50, 50, 0.75);
    -moz-box-shadow:    -1px -1px 13px rgba(50, 50, 50, 0.75);
    box-shadow:         -1px -1px 13px rgba(50, 50, 50, 0.75);
    -webkit-transition: box-shadow .3s;
}

JavaScript

setInterval(function() {
   var cl = $("div").hasClass('one') ? 'two' : 'one';
   $("div").attr('class', cl);
}, 1000);