JSFiddle - React, Tailwind, and code Playground

HTML

<div id="container">
containter text
<div id="box">
    box text
</div>
</div>

CSS

#container {
  border: solid gold 1px;   
  width: 400px;
  height: 200px;
    opacity: 0.3;
}

#box {
    border: solid silver 1px;
    margin: 10px;
    width: 300px;
    height: 100px;
        opacity: 1;
}