// ==UserScript==
// @name        Youtube-Minimizer
// @namespace   Youtube Minimizer
// @description A little extension will keep only the player on youtube page and put it to full-browser screen.
// @version     1
// @match       *://www.youtube.com/watch*
// @run-at      document-end
// @grant       none
// ==/UserScript==

(function (undefined) {
  /* Remove all elements on page except video player */
  var player_api = window.document.getElementById('player-api');
  var video_tag = player_api.getElementsByTagName('video') [0];
  var html_node = window.document.getElementsByTagName('html') [0];
  html_node.removeChild(window.document.getElementsByTagName('body') [0]);
  html_node.appendChild(player_api);
  html_node.style.backgroundColor = 'black';

  function fullPagePlayer() {
    /* Let's resize the player for fullscreen */
    player_api.style.width = window.innerWidth + 'px';
    player_api.style.height = window.innerHeight + 'px';
    video_tag.style.width = window.innerWidth + 'px';
    video_tag.style.height = window.innerHeight + 'px';
  }
  fullPagePlayer();
  window.onresize = fullPagePlayer;
}())