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

@-moz-document domain("w3schools.com") {
   table:not(:first-of-type).chapter + hr ~ *, td#rightcolumn,
   body > center > table > tbody > tr > td a:first-child + table + table + div /* top ad */ {
    display: none !important;
  }

   /* top nav */
   body > center > table > tbody > tr > td table:first-child + table,
   body > center > table > tbody > tr > td a:first-child + table + table {
     margin-bottom: 4px !important;
   }

   /* Unset this if you want the content column to stay the width it was */
   td#leftcolumn + td > table:first-child[width="574"] { width: 725px !important; }

   .left_h2 { color: inherit !important; }
}

@-moz-document url(http://w3schools.com/), url(http://www.w3schools.com/), url(http://w3schools.com/default.asp), url(http://www.w3schools.com/default.asp) {
   /* sidebar has no ads on main page */
   td#rightcolumn {
      display: table-cell !important;
   }

   /* green ad */
   body > center > table > tbody > tr > td table:first-child + table + table,

   /* flashy self-promotion lists */
   td#leftcolumn + td > table:first-child,
   td#leftcolumn + td > table:first-child + table {
     display: none !important;
   }
}