<!DOCTYPE html> <html> <head> <style type="text/css"> :root { filter: url('#g'); } </style> <style type="text/css" id="ccs"> .cc { content: 'X'; } </style> </head> <body onload="document.getElementById('ccs').disabled = true;"> <div id="g"></div> <div class="cc">5</div> </body> </html>