Q:

Firebug reporting CSS syntax error at beginning of external stylesheet

Firebug complains about a syntax error in one of my external CSS files and always blames the first line: 
SyntaxError: syntax error
For testing purposes I tried to comment out and remove the first rule completely, but the error is still displayed for the next rule. All style sheets in the file are ignored.

A:

Actually this is a JavaScript syntax error, not a CSS problem. This happens when absent-mindedly copy-pasting HTML tags and including a CSS file using a script tag. D'oh! 
Actually, the browser tries to parse the CSS content as JavaScript, which of course does not work. The solution is simple:
<script src="style.css"></script> <!-- won't work -->
<link rel="stylesheet" type="text/css" href="style.css"/> <!-- better :) -->

