1.How To Create Utility In Bootstrap Example-1
<!DOCTYPE html>
<html lang="en">
<head>
<title>Bootstrap Example</title>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.5.2/css/bootstrap.min.css">
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.5.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.16.0/umd/popper.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.5.2/js/bootstrap.min.js"></script>
<style>
.border {
display: inline-block;
width: 70px;
height: 70px;
margin: 6px;
}
</style>
</head>
<body>
<div class="container">
<h2>Borders</h2>
<p>Use a contextual border color to add a color to the border:</p>
<span class="border border-primary"></span>
<span class="border border-secondary"></span>
<span class="border border-success"></span>
<span class="border border-danger"></span>
<span class="border border-warning"></span>
<span class="border border-info"></span>
<span class="border border-light"></span>
<span class="border border-dark"></span>
<span class="border border-white"></span>
</div>
</body>
</html>
<!DOCTYPE html>
<html lang="en">
<head>
<title>Bootstrap Example</title>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.5.2/css/bootstrap.min.css">
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.5.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.16.0/umd/popper.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.5.2/js/bootstrap.min.js"></script>
</head>
<body>
<div class="container">
<h1>Shadows</h1>
<p>Use the shadow- classes to to add shadows to an element:</p>
<div class="shadow-none p-4 mb-4 bg-light">No shadow</div>
<div class="shadow-sm p-4 mb-4 bg-white">Small shadow</div>
<div class="shadow p-4 mb-4 bg-white">Default shadow</div>
<div class="shadow-lg p-4 mb-4 bg-white">Large shadow</div>
</div>
</body>
</html>
<!DOCTYPE html>
<html lang="en">
<head>
<title>Bootstrap Example</title>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.5.2/css/bootstrap.min.css">
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.5.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.16.0/umd/popper.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.5.2/js/bootstrap.min.js"></script>
</head>
<body style="height:1500px">
<div class="container-fluid">
<br>
<h3>Sticky Navbar</h3>
<p>A sticky navigation bar stays fixed at the top of the page when you scroll past it.</p>
<p>Scroll this page to see the effect. <strong>Note:</strong> sticky-top does not work in IE11 and earlier.</p>
</div>
<nav class="navbar navbar-expand-sm bg-dark navbar-dark sticky-top">
<a class="navbar-brand" href="#">Logo</a>
<ul class="navbar-nav">
<li class="nav-item">
<a class="nav-link" href="#">Link</a>
</li>
<li class="nav-item">
<a class="nav-link" href="#">Link</a>
</li>
</ul>
</nav>
<div class="container-fluid"><br>
<p>Some example text. Some example text. Some example text. Some example text. Some example text.</p>
<p>Some example text. Some example text. Some example text. Some example text. Some example text.</p>
<p>Some example text. Some example text. Some example text. Some example text. Some example text.</p>
<p>Some example text. Some example text. Some example text. Some example text. Some example text.</p>
</div>
</body>
</html>