JSFiddle - React, Tailwind, and code Playground
HTML
<div class="gradient css3"><span>css3</span></div>
<div class="gradient svg"><span>svg</span></div>
CSS
.gradient{
width:14em;
height:14em;
border:2px solid black;
background:dimgray;
display:inline-block;
line-height:14em;
}
.gradient span{
text-align:center;
color:white;
font-size:1.2em;
display:inline-block;
width:100%;
text-shadow:0 1px 2px black;
}
.gradient.css3{
background-image:-webkit-radial-gradient(50% 10%,circle,rgba(255,255,255,.3) 10%,rgba(255,255,255,0) 90%);
background-image: -moz-radial-gradient(50% 10%,circle,rgba(255,255,255,.3) 10%,rgba(255,255,255,0) 90%);
background-image: -o-radial-gradient(50% 10%,circle,rgba(255,255,255,.3) 10%,rgba(255,255,255,0) 90%);
background-image: radial-gradient(circle at 50% 10%,rgba(255,255,255,.3) 10%,rgba(255,255,255,0) 90%);
}
.gradient.svg{
background-image:url('data:image/svg+xml,%20%20%20%3Csvg%20xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg%22%3E%0A%20%20%20%20%20%20%3CradialGradient%20id%3D%22g%22%3E%0A%20%20%20%20%20%20%20%20%3Cstop%20stop-opacity%3D%22.3%22%20stop-color%3D%22white%22%20offset%3D%22.1%22%2F%3E%0A%20%20%20%20%20%20%20%20%3Cstop%20stop-opacity%3D%220%22%20stop-color%3D%22white%22%20offset%3D%22.9%22%2F%3E%0A%20%20%20%20%20%20%3C%2FradialGradient%3E%3Crect%20x%3D%220%22%20y%3D%220%22%20width%3D%22100%25%22%20height%3D%22100%25%22%20fill%3D%22url(%23g)%22%2F%3E%0A%20%20%20%20%3C%2Fsvg%3E');
}