Bar Chart Legend style issue

Hello , I am new to sencha and trying Ext charts. I could get my chart but struggling to get right style for legend. Fiddle for the same is created at http://ift.tt/1vrNYSY

I am trying to set the style properties like size, border color, border size, font but many things are not working. Documentation of Ext.Chart.Legend says that style can be configured using style attribute which can be either String or object. But it does not give any example. I probably don't know what are the exact syntax or attribute names to use under style object. Could somebody provide right attribute names for controlling width, height, font, font size, font color for legend? Thanks a ton.

Bar Chart Legend style issue