How to read a Drupal 7 node as a css file?
If you know that Drupal isn't meant to be used this way, then why would you do it? Are you trying to allow the end user to edit the CSS through the UI? There are better tools for that! (eg. Live CSS, Sweaver, Live Themer...)

If you update your question and tell us which problem you're trying to solve, we can help you much better.