inject.css

.tc-videoController {
  position: absolute;
  background: black;
  color: white;

  border-radius: 5px;
  padding: 5px;
  margin: 10px;
  line-height: 1.8em;

  cursor: default;
  z-index: 9999999;
  opacity: 0.3;

  font-family: Verdana;
  font-size: 13px;
}

.tc-videoController:hover {
  opacity: 0.7;
}

.tc-videoController:hover .tc-controls {
  display: inline;
}

.tc-controls {
  display: none;
  margin-left:1em;
}

.tc-controls button {
  cursor: pointer;
  color: black !important;
  background: white !important;
  font-weight: bold !important;
  margin: 0 2px !important;
  border-radius: 5px !important;
  padding: 3px 8px !important;
  font-size: 15px !important;
  line-height: 15px !important;
}

.tc-videoController button.tc-hideButton {
  margin: 0 2px 0 20px !important;
  opacity: 0.8;
}

/* shift controller when YouTube infobar is present */
.ytp-block-autohide:not(.el-detailpage):not(.hide-info-bar) .tc-videoController {
  margin-top: 40px;
}

body:not(.not-yt-legacy-css) .html5-video-player:not(.ytp-block-autohide):not(.el-detailpage) .tc-videoController {
    transition: margin-top .25s cubic-bezier(0.4,0,0.2,1);
    margin-top: 10px;
}

html[data-player-size=fullscreen] .tc-videoController {
  display: block;
  margin-top: 40px;
}

html[data-player-size=fullscreen] .html5-video-player:not(.ytp-block-autohide) .tc-videoController {
  transition: opacity .25s cubic-bezier(0.4,0,0.2,1);
  opacity: 0;
}

/* new YT player */
body.not-yt-legacy-css .el-embedded .tc-videoController {
  margin-top: 50px;
}

body.not-yt-legacy-css .ytp-fullscreen .tc-videoController {
  display: block;
  margin-top: 60px;
}

body.not-yt-legacy-css .ytp-autohide .tc-videoController {
  transition: opacity .25s cubic-bezier(0.4,0,0.2,1);
  opacity: 0;
}

/* shift controller on Vine embeds: mute always visible */
/* e.g. https://twitter.com/Vine_Football/status/550614684575858688 */
.video-container .tc-videoController {
  margin-top: 12px;
  margin-left: 55px;
}

/* shift controller on vine.co */
/* e.g. https://vine.co/v/OrJj39YlL57 */
.video-container .vine-video-container .tc-videoController {
  margin-left: 40px;
}

/* shift YT 3D controller down */
/* e.g. https://www.youtube.com/watch?v=erftYPflJzQ */
.webgl-pan-button {
  top: 50px !important;
}

html[data-player-size=fullscreen] .webgl-pan-button {
  top: 80px !important;
}