<!-- Fixed navbar -->
    <nav class="navbar navbar-expand-lg navbar-dark bg-dark">
      <div class="container">
        <a class="navbar-brand" href="https://reezhdesign.com">ReeZh Design</a>
        <button class="navbar-toggler" type="button" data-bs-toggle="collapse" data-bs-target="#navbarMain" aria-controls="navbarMain" aria-expanded="false" aria-label="Toggle navigation">
          <span class="navbar-toggler-icon"></span>
        </button>        
        <div class="collapse navbar-collapse" id="navbarMain">
          <ul class="navbar-nav ms-auto mb-2 mb-lg-0">
            <li class="nav-item">
              <a class="nav-link active" aria-current="page" href="#">Home</a>
            </li>
            <li class="nav-item">
              <a class="nav-link" href="#">Link</a>
            </li>
            <li class="nav-item dropdown">
              <a class="nav-link dropdown-toggle" href="#" id="navbarDropdown" role="button" data-bs-toggle="dropdown" aria-expanded="false">
                Dropdown
              </a>
              <ul class="dropdown-menu" aria-labelledby="navbarDropdown">
                <li><a class="dropdown-item" href="#">Action</a></li>
                <li><a class="dropdown-item" href="#">Another action</a></li>
                <li><hr class="dropdown-divider"></li>
                <li><a class="dropdown-item" href="#">Something else here</a></li>
              </ul>
            </li>
            <li class="nav-item">
              <a class="nav-link disabled">Disabled</a>
            </li>
          </ul>
        </div><!--/.nav-collapse -->
      </div>
    </nav>
    <div class="container jumbo">
      <!-- Main component for a primary marketing message or call to action -->
      <div class="card bg-light text-dark shadow">
        <div class="card-body">
          <h1 class="card-title">Bootstrap 5 Navbar Slide In On Scrolldown</h1>
          <p class="lead">This example is a quick exercise to illustrate how the default, static and fixed to top navbar work. It includes the responsive CSS and HTML, so it also adapts to your viewport and device.</p>
          <p>To see the difference between static and fixed top navbars, just scroll. This pen has been updated to Bootstrap 5.1.3</p>
          <p class="fs-3">Enjoy!</p>
        </div>
      </div>
    </div> <!-- /container -->
<div class="container">
  <a href="https://reezhdesign.com" rel="author">ReeZh Design</a>
</div>
@import url("https://fonts.googleapis.com/css?family=Open+Sans:400,400i,700");

// Colors
$navbar-white: #fafafa;
$navbar-black: #131313;
$navbar-active-color: #fafafa;
$navbar-bg-active-color: #ff9900;
$bg-light-blue: #00c6ff;
$bg-dark-blue: #0072ff;

html, body {
  margin: 0;
  padding: 0;
  width: 100%;
  min-height: 100vh;
}
body {
  font-family: "Open Sans", sans-serif;
  background: #e0e0e0;
}
.jumbo {
  padding-top: 100px;
  min-height: 200vh;
}

// On Shrink
.shrink {
  .navbar {
    color: $navbar-white;
    background: $bg-light-blue;
    background: -webkit-linear-gradient(55deg,$bg-light-blue 10%,$bg-dark-blue 90%);
    background: linear-gradient(35deg,$bg-light-blue 10%,$bg-dark-blue 90%);
  }
}
View Compiled
(function($) {
  $( window ).scroll( function () {
    if ( $(document).scrollTop() > 300 ) {
      // Navigation Bar
      $('.navbar').removeClass('fadeIn');
      $('body').addClass('shrink');
      $('.navbar').addClass('fixed-top animated fadeInDown');
    } else {
      $('.navbar').removeClass('fadeInDown');
      $('.navbar').removeClass('fixed-top');
      $('body').removeClass('shrink');
      $('.navbar').addClass('animated fadeIn');
    }
  });  
})(jQuery);

External CSS

  1. https://cdn.jsdelivr.net/npm/bootstrap@5.1.3/dist/css/bootstrap.min.css
  2. https://cdnjs.cloudflare.com/ajax/libs/animate.css/4.1.1/animate.min.css

External JavaScript

  1. https://cdnjs.cloudflare.com/ajax/libs/jquery/3.6.0/jquery.min.js
  2. https://cdn.jsdelivr.net/npm/bootstrap@5.1.3/dist/js/bootstrap.bundle.min.js