BeautyTips - how to change baloons text font-size?

Hello,

$('#example6').bt({

cssStyles: {color: '#FFF', fontWeight: 'bold', font-size: 'larger'}
});

Why I get this

missing : after property id
http://www.lullabot.com/files/bt/bt-latest/DEMO/demofiles/demo.js
Line 68

error when I add

font-size: 'larger' ?