Live
<h1>This is heading 1</h1><h2>This is heading 2</h2><h3>This is heading 3</h3><h4>This is heading 4</h4><h5>This is heading 5</h5><h6>This is heading 6</h6>
External CSS
This Pen doesn't use any external CSS resources.
External JavaScript
This Pen doesn't use any external JavaScript resources.