If you want to store your style-sheet somewhere on your site as a separate file, you can import it into whatever pages you want to apply it to. Just use this line of code, which goes into the <head> of your HTML document. It can also be hacked into the <body> if need be.
view source
print?
1 <style>
2
3 @import url(http://www.yoursite/stylesheets/acoolstyle.css);
4
5 </style>