This is more likely an issue at your server side. you request style sheet page "Styles/Site.css" from the server of type "text/css", but your server might be responding to this request with "test/html". I had this issue when my server was running in python and it was replying to requested css files with header text/html (as that of my index.html file). I re-arranged my server code and assigned the correct headers to its corresponding pages and my issue got resolved.
