Host your stylesheet with Dropbox
When linking a file to dropbox, the service includes some custom styles and scripts in the document to preview the document online.
Add the stylesheet to your dropbox and grab the Public Link.
If you open the share link directly in the browser and view the source code (example file) :
You can see the source has some styles and scripts. Now, replace the www with dl
That will not show any of the inserted styles and scripts. To add it to your website:
<link href="https://dl.dropboxusercontent.com/u/7872571/normalize.css" media="all" type="text/css" rel="stylesheet">