JSFiddle - React, Tailwind, and code Playground
HTML
<div id="redBar"></div>
<div id="heading"> Heading</div>
CSS
#redBar{ width: 100%; height: 10px; z-index: -1; margin-top: 80px; background: #D2232A;}
#heading{ width: 768px; margin-left: auto; margin-right: auto; margin-top: 80px;}