YouTubeTheme.css

@-moz-document domain(youtube.com) {
	
	.html5-play-progress, .ytp-play-progress {
   background: #191970 !important; /* Old browsers */
   background: -moz-linear-gradient(left, #191970 0%, #191970 100%) !important;
   background: -webkit-gradient(linear, left top, right top, color-stop(0%,#1b1b1b), color-stop(100%,#FFFFFF)) !important;
   background: -webkit-linear-gradient(left, #191970 0%,#8b0000 100%) !important;
   background: -o-linear-gradient(left, #191970 0%,#8b0000 100%) !important;
   background: -ms-linear-gradient(left, #191970 0%,#8b0000 100%) !important;
   background: linear-gradient(to right, #191970 0%,#006400 50%,#8b0000 100%) !important;
}
.html5-load-progress, .ytp-load-progress {
   background: #606060 !important;
}
/* actual scrubber button */
.html5-scrubber-button, .ytp-scrubber-button {
   background: #cc0000 !important;
   border-color: #1B1B1B !important;
   box-shadow: 0px 0px 3px #8b0000, 0px 0px 5px #fd482f, 0px 0px 0px #ee3a8c !important;
   transition: box-shadow 0.2s, background 0.2s !important;
}
/* scrubber button on hover */
.ytp-scrubber-button, .html5-scrubber-button:hover, .ytp-scrubber-button:hover {
   background: #660066 !important;
   border-color: #1B1B1B !important;
   box-shadow: 0px 0px 6px #8b0000, 0px 0px 8px #fd482f, 0px 0px 10px #ee3a8c !important;
}
/* volume control */
.ytp-volume-slider-foreground:before {
   background: #191970 !important; /* Old browsers */
   background: -moz-linear-gradient(left, #191970 0%, #191970 100%) !important;
   background: -webkit-gradient(linear, left top, right top, color-stop(0%,#191970), color-stop(100%,#660066)) !important;
   background: -webkit-linear-gradient(left, #191970 0%,#191970 100%) !important;
   background: -o-linear-gradient(left, #00ffff 0%,#191970 100%) !important;
   background: -ms-linear-gradient(left, #00ffff 0%,#00ffff 100%) !important;
   background: linear-gradient(to right, #191970 0%,#006400 50%,#8b0000 100%) !important;
}

body {
  overflow-x: hidden;
}

body[data-spf-name='watch'] #yt-masthead-container {
  opacity: 0;
  transition: opacity .2s .3s;
}
body[data-spf-name='watch'] #yt-masthead-container:hover {
  opacity: 1;
}

.watch-stage-mode .html5-video-content, .watch-stage-mode video {
  width: 100%!important;
  height: 100vh!important;
}

.html5-video-content,
.ad-container,
video,
#content,
.player-width,
.player-height {
  transition: all .2s;
}
.watch-stage-mode .player-width {
  width: 100%;
}
.watch-stage-mode .player-height {
  height: 100vh;
}
.watch-stage-mode .html5-video-container video {
  top: 0!important;
  left: 0!important;   
}
.watch-stage-mode #player, .watch-stage-mode #placeholder-player {
  margin-top: -60px;
}
.watch-stage-mode .player-width, .ytp-chrome-bottom, #watch7-container {
  left: 0;
  right: 0;
  margin: 0 auto;
}
.watch-stage-mode #watch7-container {
  max-width: 1280px;
  display: flex;
  justify-content: center;
}
.watch-stage-mode .ytp-tooltip.ytp-preview {
  left: 0!important;
  right: 0!important;
  top: auto!important;
  bottom: 50px;
  margin: 0 auto;
  max-width: 96px!important;
}
.watch-stage-mode .ytp-tooltip.ytp-bottom {
  top: inherit!important;
  bottom: 50px;
}
#a11y-announcements-container {
  visibility: hidden;
}
.watch-stage-mode .ad-container {
  width: 100vw!important;
  height: 100vh!important;
}
.watch-stage-mode .video-ads {
  pointer-events: none;
}
.watch-stage-mode .close-padding {
  pointer-events: auto;
}

/* 360 video */
.watch-stage-mode .html5-video-container {
  height: 100vh;
  width: 100vw;
  display: flex;
  flex-flow: row wrap;
  justify-content: center;
}
.watch-stage-mode .webgl {
  top: 50%!important;
  transform: translateY(-50%);
  display: flex;
  width: 100vw;
  height: 100%;
  justify-content: center;
}
.watch-stage-mode .webgl canvas {
  height: inherit;
}
.watch-stage-mode .ytp-webgl-spherical-control {
  top: 60px!important;  
}

/* Playlist */
.watch-stage-mode #player-playlist .watch-playlist {
  top: 10px;
}
.watch-wide #player-playlist .watch-playlist {
  -moz-transform: translateY(100vh);
  -ms-transform: translateY(100vh);
  -webkit-transform: translateY(100vh);
  transform: translateY(100vh);
}

/* Frame preview */
.watch-stage-mode .ytp-storyboard {
  transform: translateX(16.5%);
}
.watch-stage-mode .ytp-storyboard-framepreview {
  display: none!important;
}

/* Annotations */
.watch-stage-mode .ytp-iv-video-content {
  left: 50%!important;
  top: 50%!important;
  transform: translateX(-50%) translateY(-50%);
  z-index: 10;
  pointer-events: none;
}
.watch-stage-mode .ytp-iv-video-content * {
  pointer-events: auto;
}

}