Is there a single CSS selector I can use to change the following:

• Height and corner radia of ALL the rectangular submit buttons (those for posting, replying, answering, and similar). I may also want to remove the border or add a drop shadow.
• The blue color of the small “V” arrow for expanding/collapsing recent posts on the front page clashes a bit with my color scheme. I‘d like to change its color.
• I’d also like to change the height of all the category title bars and maybe the menu bar.

If you have documentation on all your css selectors, could you direct me to the page so I can check there if I want further changes? 

Thank you!