<!DOCTYPE html>
<html>
<head>
<style type="text/css">

body { font-family: monospace; width: 10ch; outline: 1px solid black; }
div { -moz-column-width: 0.4px; -moz-column-gap: 3ch; }
b { font-weight: inherit; display: inline-block; }
#r { border: 1px solid red; }
#r:before { content: ""; }

</style>

<script type="text/javascript">

function boom()
{
  document.getElementById("r").style.counterReset = "c";
}
</script>

</head>

<body onload="boom();"><div>a b c d <span> <b>m</b><span id="r"><b>x</b><span></span></span></span> </div></body>

</html>