// ==UserScript==
// @exclude *.mail.yahoo.com/*
// ==/UserScript==

(function() {
  var html = document.firstChild && document.selectSingleNode('/html');
  if (html)
    html.className += ' ' + location.hostname.replace(/\./g, '-').replace(/^www-|[^\w- ]/g, '').replace(/\b(\d)/g,'_$1');
})();