<!DOCTYPE html>
<html>
<head>
<style>
h1:before {
counter-increment: section;
content: "Section " counter(section) ". ";
}
</style>
</head>
<body>
<p>Click the "Try it" button to set the counter-reset property of the BODY element:</p>
<button onclick="myFunction()">Try it</button>
<h1>HTML Tutorials</h1>
<h1>JavaScript Tutorials</h1>
<h1>CSS Tutorials</h1>
<script>
function myFunction() {
document.body.style.counterReset = "section";
}
</script>
</body>
</html>