JSFiddle - React, Tailwind, and code Playground

HTML

<div id="ctMenu">
<ul>
    <li><a href="#">WELCOME</a></li>
    <li><a href="#">ABOUT US</a></li>
    <li><a href="#">CONTACT</a></li>
</ul>

CSS

#ctMenu { width:1010px; margin: 20px 0 0 0; padding:20px 0 20px 0}
#ctMenu ul { margin:0; padding:0;}
#ctMenu ul li { margin-left: 0; margin-bottom:0;  display:inline;}
#ctMenu ul li a { padding: 10px 25px 9px 25px; background-color:green; text-decoration: none; color:Black; font-weight:bold; }
#ctMenu ul li a:hover {background-color:Gray; }
#ctMenu ul li a.selected { background-color: yellow }

JavaScript

$(function() {
    $("#ctMenu ul li a").click(function() {
      $("#ctMenu ul li a").removeClass('selected');
      $(this).addClass('selected');
    });
});