YSlow 'Put CSS at the top' Bug

And a workaround.

It looks like YSlow v0.9.5b2 has a bug regarding the way it grades CSS. Basically, any file included using @Import is interpreted by YSlow as an external file. There is some discussion about this bug on the Yahoo developers page here. One interesting point brought up by a commenter is that IE renders @Import files differently than other browsers, but I wasn't able to find any information to back up that claim.

As far as I can tell it shouldn't make any difference whether local CSS files are included using @Import or <link rel="...">. So, unless you are looking for a perfect score it should be okay to leave the @Imports where they are.

Steve Souders wrote up a very informative post concerning this issue. Basically, if you mix and match link tags and @import tags they will be loaded serially by the browser instead of in parallel. So, if you stick to just one method then everything should be okay.

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