Example.html
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <h1>First header</h1>
    <h2>Second header</h2>
    <h3>Third header</h3>
    <h4>Fourt header</h4>
    <h5>Fith header</h5>
    <h6>Sixt header</h6>
</body>
</html>