<!DOCTYPE html>
<html>
<head>
<title>Title of the document</title>
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.4.1/css/bootstrap.min.css">
</head>
<body>
<h1>Example</h1>
<span class="glyphicon glyphicon-heart icon-green"></span>
<span class="glyphicon glyphicon-star icon-large"></span>
<span class="glyphicon glyphicon-th icon-red"></span>
</body>
</html>