<!DOCTYPE html> <html> <head> <script> function boom() { document.documentElement.offsetHeight; document.getElementById("x").style.counterIncrement = "a"; document.documentElement.offsetHeight; } </script> <body onload="boom();" style="-moz-column-count: 3"> <div style="position: relative;"> <div style="position: absolute; height: 3pt;"></div> <div style="position: absolute;" id="x"></div> <div style="position: absolute; height: 8pt;"></div> </div> </body> </html>