In your custom CSS you have this:
The "font-weight:bold" part of that block makes all links bold unless they are styled by a more specific rule later to make them not bold. Remove that rule to make the links have a normal font weight.
In your custom CSS, you have this:
When you use url() in the custom CSS editor, then you must put a complete URL inside of that function starting with http://
It appears you copy and pasted the entire original stylesheet into your custom CSS editor. That makes some things break (which you can see). Instead of doing that, you should just copy in CSS for things you'd like to change instead of the entire original theme stylesheet.