<!DOCTYPE html> 
<html>
<head>
<style>

  #colset { 
    -moz-column-count: 2; 
    -moz-column-gap: 0; 
    border: 2px solid black; 
    height: 12em; 
  }

  #b { 
    margin: 10em 0pt; 
  }

  #i { 
    margin: 12em 0pt; 
    float: left; 
    -moz-appearance: radio-small;
  }

</style>
</head>

<body onload="document.getElementById('i').style.padding = '1em 0';">

<div id="colset"><br id="b"><div id="i"></div></div>

</body>
</html>