@-moz-document
url-prefix("http://www.google.com/search"), 
url-prefix("https://www.google.com/search"), 
url-prefix("http://www.google.com/webhp"),
url-prefix("https://www.google.com/webhp"),
url-prefix("http://www.google.com/#"),
url-prefix("https://www.google.com/#"),
domain("mail.google.com"),
domain("talkgadget.google.com"),
domain("news.google.com"),
domain("facebook.com"),
domain("reddit.com") {
    * {font-family: 'Open Sans' !important;}
}