<!DOCTYPE html>
<html>
<head>
<style>
h1 {
counter-increment: section;
}
h1:before {
content: "Section " counter(section) " ";
}
</style>
</head>
<body>
<h1>HTML Tutorial</h1>
<h1 id="myH1">CSS Tutorial</h1>
<h1>JavaScripts Tutorial</h1>
<p>Click the "Try it" button to change the counterIncrement of the second H1 element:</p>
<button onclick="myFunction()">Try it</button>
<script>
function myFunction() {
document.getElementById("myH1").style.counterIncrement = "subsection";
}
</script>
</body>
</html>