Is there a way I could copy a pages CSS
Tools -> View Source and find the CSS file in the header. I don't encourage stealing peoples work.
By do that though, you can be sued, lose your hosting etc etc etc.
well if you want to look at a pages CSS you can download the addon for Firefox called firebug, you just right clikc and inspect elements, so whatever part of the page you click, it will show its CSS, HTML etc.