Buddypress Group Comment & Styling

Hi, I want to start using group messages to send info to members and have them comment there.

The font size of any comments to a message is tiny, too small to read..

Can you tell me where I would customise this?

Also do you know how I would style the Buddypress group and profile to look better. I don't like the default border around the buddy press left hand area.

Many thanks for help