JSFiddle - React, Tailwind, and code Playground

HTML

<div class="main">main</div>

<div class="main another">another</div>

CSS

.main {
  background: red;
  color: gray;
  display: inline;
  .another
}

.main.another {
  width: 50px;
  height: 100px;
  background: blue;
}