CSS Source File and Mime Type

I've coded a CSS file with class references for a floating window.

// Cascading Stylesheet
.clDescription {width:200px; left:0px; top:0px; font-family:verdana,arial,helvetica,sans-serif; overflow:hidden; border: 1px solid #999999; padding:3px; font-size:11px; background-color:#cccccc; layer-background-color:#cccccc;}
.clCaption {position:absolute; left:0px; top:0px; width:208px; height:15px; clip:rect(0px 208px 15px 0px); font-size:11px; font-family:verdana,arial,helvetica,sans-serif; background-color:#999999; layer-background-color:#999999;}

<style src=css_file.css></style>

The issue I've run into is this works fine in NS but not in IE.

I moved the CSS code into the html file

<style type=\"text/css\">
.clDescription {width:200px; left:0px; top:0px; font-family:verdana,arial,helvetica,sans-serif; overflow:hidden; border: 1px solid #999999; padding:3px; font-size:11px; background-color:#cccccc; layer-background-color:#cccccc;}
.clCaption {position:absolute; left:0px; top:0px; width:208px; height:15px; clip:rect(0px 208px 15px 0px); font-size:11px; font-family:verdana,arial,helvetica,sans-serif; background-color:#999999; layer-background-color:#999999;}
</style>

and it works fine in both NS and IE?

When I read up on the CSS file (O'Reilly HTML & XHTML) it said by default the CSS source file is read as a text/css mime type. Of course, I can code this type when it's in the html but how can I define a text/css mime type for a CSS source file?

Regards,

LEO