@namespace url(http://www.w3.org/1999/xhtml);

@-moz-document domain("www.google.com") {
    div.item-body img {
        opacity:0.05 !important;
    }
    div.item-body img:hover {
        opacity:0.30 !important;
    }
}

@-moz-document domain("www.google.com.br") {
    div.item-body img {
        opacity:0.05 !important;
    }
    div.item-body img:hover {
        opacity:0.30 !important;
    }
}