Answer 1

As far as I know, you can't.. by default the CSS has to be readable by the browser, just like all client side stuff (HTML and JavaScript etc).. so by default is plain source.

I guess you can make it harder to do, by maybe spitting up your CSS rules into separate files, or injecting the rules from obfuscated JavaScript... if you can cope with the headache.

Unless there's something​ else magic out there I don't know about 😉

Answer 2

As said by Phil Servis, I don't think there's a way to do that, but you can make your CSS harder to read by minifying it.
You can use cssminifier.com to do that.