<!DOCTYPE html>
<html>
<head>
<style id="firstLetterSheet">
.fl:first-letter { }
</style>
<style id="emptySheet">
</style>
<script>
function boom()
{
document.getElementById("firstLetterSheet").textContent = "";
document.getElementById("emptySheet").textContent = ".aft:after { content: counter(chicken); }";
}
</script>
</head>
<body onload="boom()">
<div class="fl">Foo <span class="aft">Bar</span></div>
<p class="aft">Baz</p>
</body>
</html>