JSFiddle - React, Tailwind, and code Playground

HTML

<html>
  <body>
     <div class="circle">
     
     </div>
  </body>
</html>

CSS

html{
  height: 100%;
}

body{
 height: 100%;
}

.circle {
    max-width: 150px;
    width: 100%;
    max-height: 150px;
    height: 100%;
    display: block;
    background: #ff4040;
    border-radius:50%; 
}