[(#REM)-- (1) video wrapper --
modele a inserer : youtube_numerodevideo
nom du fichier modele : youtube_.html
]

<div class="youtube" data-embed="#ENV{video}"> 
 
    <!-- (2) the "play" button -->
    <div class="play-button"></div> 
     
</div>

<style>
.youtube {
    background-color: #000;
    margin-bottom: 30px;
    position: relative;
    padding-top: 56.25%;
    overflow: hidden;
    cursor: pointer;
}
.youtube img {
    width: 100%;
    top: -16.84%;
    left: 0;
    opacity: 0.7;
}
.youtube .play-button {
    width: 90px;
    height: 60px;
    background-color: #333;
    box-shadow: 0 0 30px rgba( 0,0,0,0.6 );
    z-index: 1;
    opacity: 0.8;
    border-radius: 6px;
}
.youtube .play-button:before {
    content: "";
    border-style: solid;
    border-width: 15px 0 15px 26.0px;
    border-color: transparent transparent transparent #fff;
}
.youtube img,
.youtube .play-button {
    cursor: pointer;
}
.youtube img,
.youtube iframe,
.youtube .play-button,
.youtube .play-button:before {
    position: absolute;
}
.youtube .play-button,
.youtube .play-button:before {
    top: 50%;
    left: 50%;
    transform: translate3d( -50%, -50%, 0 );
}
.youtube iframe {
    height: 100%;
    width: 100%;
    top: 0;
    left: 0;
}
</style>
<script type="text/javascript">
( function() {

	var youtube = document.querySelectorAll( ".youtube" );
	
	for (var i = 0; i < youtube.length; i++) {
		
		var source = "https://img.youtube.com/vi/"+ youtube[i].dataset.embed +"/sddefault.jpg";
		
		var image = new Image();
				image.src = source;
				image.addEventListener( "load", function() {
					youtube[ i ].appendChild( image );
				}( i ) );
		
				youtube[i].addEventListener( "click", function() {

					var iframe = document.createElement( "iframe" );

							iframe.setAttribute( "frameborder", "0" );
							iframe.setAttribute( "allowfullscreen", "" );
							iframe.setAttribute( "src", "https://www.youtube.com/embed/"+ this.dataset.embed +"?rel=0&showinfo=0&autoplay=1" );

							this.innerHTML = "";
							this.appendChild( iframe );
				} );	
	};
	
} )();

</script>