Making block reading from a certain css file

[Ruscon]

My question is, how to make a block read from a certain css? Right now if my index.template.php reads for example test.css, then the blocks from TP won't read from that css if they have a given class. How to make a block read from that css file aswell?

Thanks for your time! 

[IchBin]

If you have the css file linked in your index.template.php file, the blocks will pick that up automatically.