javascript: (function() {
  var css =
      "a:focus, input:not(disabled):focus, textarea:focus, button:focus, select:focus { outline: 3px solid !important; transition: all linear 0.2s; }",
    head = document.head || document.getElementsByTagName("head")[0],
    style = document.createElement("style");
  style.type = "text/css";
  if (style.styleSheet) {
    style.styleSheet.cssText = css;
  } else {
    style.appendChild(document.createTextNode(css));
  }
  head.appendChild(style);
  var div = document.createElement("div");
  div.innerHTML = "Focus Enabled";
  div.style.position = "fixed";
  div.style.bottom = 0;
  div.style.right = 0;
  div.style.background = "blue";
  div.style.color = "white";
  document.body.appendChild(div);
})();