JSFiddle - React, Tailwind, and code Playground

HTML

<div id="centerDiv">
    <h1>title 1</h1>
    <h3>title 3</h3>
</div>

CSS

h1 {
  color: #666;
  margin: 20px 10px 0px;
  padding: 0px 30px 0px 30px;
  text-align: center;
}

h3 {
  color: #ccc;
  background-color: black;
  margin: 0px;
  padding: 10px 10px 10px 10px;
  text-align: center;
  display: inline-block;
  border:2px solid green;
  margin:auto 0px !important;
  
}

/*Changes to the Code*/
#centerDiv{
  border:1px solid red;
  text-align:center;
  }