JSFiddle - React, Tailwind, and code Playground

HTML

<div id="hello">
  <div>
    <div id="baddiv"></div>
  </div>
  <div></div>
</div>

CSS

#hello {
  display: flex;
  width: 500px;
}
#hello > div {
  height: 50px;
}
#hello > div:first-child {
  background-color: yellow;
}
#hello > div:last-child {
  background-color: red;
  flex: 0 0 200px;
}
#baddiv {
  width: 400px;
  height: 20px;
  background-color: purple;
}