How to change the layout/formatting/css of the Comment Submission form?

I can't find the file anywhere - to change the styling and information on the Comment Submission form. Here's my page example: http://sleddoggin.com/site-news-updates/win-a-book-forum-competition-win...

Down below you will see all of the tweaks and styling I've done for the comments - but I can't figure out how to make the form text bigger, etc...through styles...I can't find the styles, or text outputting functions anywhere. Do you happen to know where this would be located? Thanks!

I'd also like to get rid of the INPUT FORMATTING options text below the comment submission form. Where would I find that code - or is there an option to check in Drupal admin?

Thank you!