JSFiddle - React, Tailwind, and code Playground

HTML

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Document</title>
</head>
<body>
  <div class="form"></div>
</body>
</html>

CSS

.form {
  width:500px;
  height:400px;
  background-color:#444;
  border-radius:15em/4em ;
}