To be used with chrome's extension - Stylish

youtube hide classes.css

/* `Set Applies` to `www.youtube.com` */
/* URLs on the domain www.youtube.com */
.ytp-chrome-bottom {
	visibility: hidden;
}
/* above is for player controls hiding. */

.caption-window.ytp-caption-window-bottom{
	margin-bottom: 0px
}
/* above is for removing bottom margins for captions.   */

.iv-click-target{
	visibility: hidden;
}
/* above is for hiding right-bottom channel picture. */

.ytp-gradient-bottom{
	visibility: hidden;
}
/* above is for hiding dark shade when we hover over video or when video is paused. */

.ytp-bezel-text-hide{
	visibility: hidden;
}
/* above is to hide play/pause animations that appear in middle of player */

.branding-context-container-inner{
	visibility: hidden;
}
/* above is to hide subscribe button on the bottom right side of the player */