JSFiddle - React, Tailwind, and code Playground

by jmarikle

HTML

<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.1.3/css/bootstrap.min.css">
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.14.3/umd/popper.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.1.3/js/bootstrap.min.js"></script>

<body data-spy="scroll" data-target=".navbar" data-offset="15">
  <nav class="navbar navbar-expand-sm navbar-dark bg-dark fixed-top">
    <ul class="navbar-nav">
      <li class="nav-item">
        <a class="nav-link" href="#section1">Section 1</a>
      </li>
      <li class="nav-item">
        <a class="nav-link" href="#section2">Section 2</a>
      </li>
      <li class="nav-item">
        <a class="nav-link" href="#section3">Section 3</a>
      </li>
    </ul>
  </nav>

  <div id="section1" class="container-fluid bg-light page-section">
    <h1>Section 1</h1>
    <p>Try to scroll this section and look at the navigation bar while scrolling! Try to scroll this section and look at the navigation bar while scrolling!</p>
    <p>Try to scroll this section and look at the navigation bar while scrolling! Try to scroll this section and look at the navigation bar while scrolling!</p>
  </div>
  <div id="section2" class="container-fluid bg-dark page-section">
    <h1>Section 2</h1>
    <p>Try to scroll this section and look at the navigation bar while scrolling! Try to scroll this section and look at the navigation bar while scrolling!</p>
    <p>Try to scroll this section and look at the navigation bar while scrolling! Try to scroll this section and look at the navigation bar while scrolling!</p>
  </div>
  <div id="section3" class="container-fluid bg-light page-section">
    <h1>Section 3</h1>
    <p>Try to scroll this section and look at the navigation bar while scrolling! Try to scroll this section and look at the navigation bar while scrolling!</p>
    <p>Try to scroll this section and look...

CSS

.page-section {
  padding: 70px 10px
}

.page-section.bg-dark * {
  color: #fff;
}

JavaScript

$(window).on('activate.bs.scrollspy', function (e,obj) {
  if ((window.innerHeight + window.pageYOffset) >= document.body.offsetHeight) {
  	return;
  }
	var isBGLight = $(obj.relatedTarget).hasClass('bg-light');
  $('.navbar').toggleClass('navbar-dark bg-dark', isBGLight)
              .toggleClass('navbar-light bg-light', !isBGLight);
});