#header {
	background-color: #ffffff;
	background-image: url("Img/nenuphars.jpeg");
	-webkit-background-size: cover; /* pour anciens Chrome et Safari */
	background-size: cover; /* version standardisée */
	background-repeat: no-repeat;
	background-position : center center;
	opacity: 0.7;
	filter: alpha(opacity=70);
	width:100%;
	text-align:center;
	}