I think my theme is messing with my appointments page so

Hello,
I think my theme is messing with my appointments page so I wanted to use some css to fix things.

All I want is for borders to be around things. For example, my "My appointments" section is transparent and has no table dividers so it's just the words floating there. What can I do to make things look more defined? Also with the calendar, the lines there are all very thin and I want to make them bolder.

Thank you very much!