JSFiddle - React, Tailwind, and code Playground

HTML

<div class="menuItem">Hello!</div>

CSS

div.menuItem {
    background-color: #09C;
    border: 3px solid #F00;
    color: #FFF;
    margin: 30px;
    padding: 30px;
}

div.menuItem {
    -moz-transition: background-color 0.5s, border-radius 0.5s;
    -o-transition: background-color 0.5s, border-radius 0.5s;
    -webkit-transition: background-color 0.5s, border-radius 0.5s;
}

div.menuItem:hover {
  border-radius: 145px 85px 145px 85px;
  background-color: #000000;
}