<!DOCTYPE html>
<html>
<head>
<style type="text/css">
#div:first-letter { float: left; color: lightgreen; }
</style>
<script type="text/javascript">
function boom()
{
document.getElementById("div").className = "anything";
}
</script>
</head>
<body onload="boom()">
<div id="div"><span style="color: magenta">Foo</span> bar</div>
</body>
</html>