Quirk: If the document has been set to [quirks mode](https://dom.spec.whatwg.org/#concept-document-quirks), has the [same origin](https://html.spec.whatwg.org/#same-origin) as the [URL](https://url.spec.whatwg.org/#concept-url) of the external resource, and the [Content-Type metadata](https://html.spec.whatwg.org/#content-type) of the external resource is not a supported style sheet type, the user agent must instead assume it to be [text/css](https://html.spec.whatwg.org/#text/css).