darkify

/*CODE*/

var element = content.document.getElementById("blackify");
if (element) {
  element.parentNode.removeChild(element);
} else {
  var style = content.document.createElement("style");
  style.setAttribute("type", "text/css");
  style.setAttribute("id", "blackify");
  style.innerHTML =
        "::-moz-selection { background: orange; color: #111 } " +
        "*         { background: #111 !important; " +
        "            border-color: #000 !important;   " +
        "            border-bottom-color: #000 !important;   " +
        "            border-left-color: #000 !important;   " +
        "            border-right-color: #000 !important;   " +
        "            border-top-color: #000 !important;   " +
        "            text-shadow: none !important;   " +
        "            color: orange !important; } " +

        "p,div     { text-align: left !important; } " +
        "pre, code, tt {      background: #000 !important; } " +
        "a         {      color: orangered !important; } " +
        "a:hover   {      color: red !important; } " +
        "a:visited {      color: peru !important; } ";


  content.document.getElementsByTagName("head")[0].appendChild(style);
}