JSFiddle - React, Tailwind, and code Playground

HTML

<div class="out"><span>example</span></div>

CSS

div {
animation:demo 7s;
-moz-animation:demo 7s; /* Firefox */
-webkit-animation:demo 7s; /* Safari and Chrome */
-o-animation:demo 7s; /* Opera */
animation:demo 7s infinite;
}

@keyframes demo 
{
0% {opacity:0;}
50% {opacity:1;}
100% {opacity:0;}