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

@-moz-document domain("itmedia.co.jp") {
 .rc,
 .header,
 #txtad,
 #btnlist,
 .prtbtn,
 .adExpandSBBase,
 #adExpandSBBase,
 .adsense,
 #l200{
  display : none;
 }
 .l600 {
  margin : 1em 2em !important;
 }
 .lcrc {
  padding : 0px 0px 0px 0px !important;
 }
}