JSFiddle - React, Tailwind, and code Playground

by booktu8

HTML

<div class="father">
  <div class="son">

  </div>
</div>

CSS

.father {
  width: 300px;
  height: 200px;
  background-color: pink;
}

.son {
  width: calc(100% - 30px);
  height: 30px;
  background-color: blue;
}