#backgroundSite_Droite {
	position: fixed;
	right: 0;
	height: 100%;
	width: 25%;
	/*z-index: -1;*/
	text-align: left;
}

.backgroundSite {
	position: absolute;
	right: 0;
	height: 100%;
	width: 100%;
	/*z-index: -1;*/
}
@media screen and (max-width: 1200px) {
	#backgroundSite_Gauche {
		display: none;
	}
	
	#backgroundSite_Droite {
		display: none;
	}
}
#backgroundSite_Gauche {
	position: fixed;
	left: 0;
	height: 100%;
	width: 25%;
	/*z-index: -1;*/
	text-align: left;
	/*background-color: red;*/
}

.option_backgroundSite {
	position: absolute;
    top: 500px;
    transform: translateY(-50%)translateX(-50%);
    left: 50%;
	background-color: white;
	border: 1px solid blue;
	padding: 10px;
	z-index: 1;
	text-align: right;
	opacity: 0.8;
}