.illustration {
	position: relative;
	margin: 0 auto;
	width : 716px;
	height: 413px;
	background : url("./illustration.jpg");
    background-size: cover;
    webkit-background-size: cover;
    moz-background-size: cover;
    o-background-size: cover;
}

 
.i-large,
.i-medium,
.i-small {
	position : absolute;
	top: 0; right: 0; bottom: 0; left: 0;
}
 
.i-large {
	background: url("./particules_large.png") repeat 0px 0px;
	-webkit-animation: dropFlowParticles 2s linear infinite;
	     -o-animation: dropFlowParticles 2s linear infinite;
	        animation: dropFlowParticles 2s linear infinite;
}
.i-medium {
	background: url("./particules_medium.png") repeat 0px 0px;
	-webkit-animation: dropFlowParticles 12s linear infinite;
	     -o-animation: dropFlowParticles 12s linear infinite;
	        animation: dropFlowParticles 12s linear infinite;
}
.i-small {
	background:url("./particules_small.png") repeat 0px 0px;
	-webkit-animation: dropFlowParticles 27s linear infinite;
	     -o-animation: dropFlowParticles 27s linear infinite;
	        animation: dropFlowParticles 27s linear infinite;
}
 
@-webkit-keyframes dropFlowParticles {
	from { background-position: 0 0; }
	to { background-position: 0 413px; }
}
@keyframes dropFlowParticles {
	from { background-position: 0 0; }
	to { background-position: 0 413px; }
}