#contenaire
{
	margin: 0 auto;
	margin-top: -3.125em;
	margin-bottom: 7.125em;
	display: block;
	width: 21.500em;
	height: 17em;
	
	perspective: 31.250em;
	position: relative;
}

#avant, #arriere
{
	display: block;
	width: 21.500em;
	height: 17em;
	margin: auto;
	background-color:  white;
	font-size: 1.250em;
	right: 0;
	
	position: absolute;
	top: 20%;

	
	/*border-radius*/
	-webkit-border-radius:10.000em;
	   -moz-border-radius:10.000em;
			border-radius:10.000em;
			
	/*transform-style*/
	-webkit-transform-style:preserve-3d;
	   -moz-transform-style:preserve-3d;
		-ms-transform-style:preserve-3d;
		 -o-transform-style:preserve-3d;
			transform-style:preserve-3d;
			
	/*transition*/
	-webkit-transition:0.8s;
	   -moz-transition:0.8s;
		 -o-transition:0.8s;
			transition:0.8s;
	
	/*backface-visibility*/
	-webkit-backface-visibility:hidden;
	   -moz-backface-visibility:hidden;
		-ms-backface-visibility:hidden;
		 -o-backface-visibility:hidden;
			backface-visibility:hidden;
	
}

#avant
{
	background-image:  url(../images/dev_web.jpg);
}

#arriere
{
	
	text-align: center;
	background-color:  #FF4E11; 
	/*linear-gradient 
	background: linear-gradient(to right, #FF4E11, #717274));
	
	background:-webkit-linear-gradient( ellipse at center top, #FF4E11, #717274);
	background:   -moz-linear-gradient( ellipse at center top, #FF4E11, #717274);
	background:     -o-linear-gradient( ellipse at center top, #FF4E11, #717274);
	background:        linear-gradient( ellipse at center top, #FF4E11, #717274); */

	color: white;
	/*transform*/
	-webkit-transform:rotateY(-180deg);
	   -moz-transform:rotateY(-180deg);
		-ms-transform:rotateY(-180deg);
		 -o-transform:rotateY(-180deg);
			transform:rotateY(-180deg);
}

#contenaire:hover #avant 
{
	/*transform*/
	-webkit-transform:rotateY(180deg);
	   -moz-transform:rotateY(180deg);
		-ms-transform:rotateY(180deg);
		 -o-transform:rotateY(180deg);
			transform:rotateY(180deg);
}

#contenaire:hover #arriere 
{
	/*transform*/
	-webkit-transform:rotateY(0deg);
	   -moz-transform:rotateY(0deg);
		-ms-transform:rotateY(0deg);
		 -o-transform:rotateY(0deg);
			transform:rotateY(0deg);
}

@media screen and (max-width:480px) {
/* Petit écran */
	#contenaire, .bloc_gris {
		display: none;
		}
		
	.PetitFormat img {
		margin: 0 4em;
		}
	}

@media screen and (min-width:481px) {
/* Moyen et Grand écran */
	.PetitFormat {
		display: none;
		}
	}