JSFiddle - React, Tailwind, and code Playground

by vals

HTML

<div class="container">
  <div class="test">TEST
  </div>
</div>

CSS

.test { 
    width: 100px;
    height: 100px;
    position: relative;
    left: 30px;
    top: 30px;
    background-color: lightgreen;
    transition: all 2s linear;
    -webkit-transform-style: preserve-3d;
}

.test:after {
    content: '';
    right: 0px;
    bottom: 0px;
    position: absolute;
    top: 0px;
    left: 0px;
    background: linear-gradient(to right, black, transparent);
    -webkit-transform: rotateY( 180deg );
    -webkit-transform-style: preserve-3d;
    -webkit-backface-visibility: hidden;
}


.container:hover .test {
  -webkit-transform: rotateY( 180deg );
}