JSFiddle - React, Tailwind, and code Playground

HTML

<div id="parent">
    <span id="child">This is test</span>
</div>

CSS

#parent{
  width: 200px;
  height: 100px;
  border: 1px solid red;
  text-align: center;
}

#child{
  line-height: 100px; /* same as parent's height */
}