<!DOCTYPE html>
<html>
<body>
<p id="myP">This is a paragraph.</p>
<button type="button" onclick="myFunction()">Adjust font size</button>
<p><b>Note:</b> The fontSizeAdjust property is only supported in Firefox.</p>
<script>
function myFunction() {
document.getElementById("myP").style.fontSizeAdjust = "0.58";
}
</script>
</body>
</html>