Does your web page look alright from your laptop's browser?

If not, then I would take a look at your (x)html again to make sure that it is including the css file correctly.

If it is correct on the laptop, then I'm not sure what to tell you... you might want to take a look at your web server log to see if the css file is being downloaded. In the log file, you should see an entry with the filename of the css file.