@document url("https://www.example.com/") {
    h1 {
        color: green;
    }
}

@document url("http://www.w3.org/"), url-prefix("http://www.w3.org/Style/"), domain("mozilla.org"), media-document("video"), regexp("https:.*") {
    body {
        color: purple;
        background: yellow;
    }
}

@document url(https://www.example.com/) {}
@-moz-document url("https://www.example.com/") {}
@-moz-document/* near */ /* filter */ url("example.com/{") /* a */ {}

@document url("https://www.example.com/") {
    @media screen and (min-width: 900px) {
        article {
            padding: 1rem 3rem;
        }
    }
}