GooglePlusButton widget customization

I am using the GoogleHybrid auth client and it works great. However it shows a square Google+ icon button (shown below) and I am unable to change or customize it which works fine for Facebook and Twitter clients.

GoogleHybrid uses GooglePlusButton to render the button and comes with as per the documentation, button can be customized using [color=#333333][font=Consolas,]buttonHtmlOptions[/font][/color][size=2] but when I do that, the button stops working. I tried adding class to the button but that doesn’t seem to apply and button also stops working. I tried using style as well but that also has no effect. [/size]

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[size=2]In short, I need to show google button similar to facebook and twitter button as shown above which are using bootstrap’s btn btn-block class with little bit of custom CSS for colors.[/size]