body {
	background-image:url(../images/bg.jpg);
	background-size:cover;
	height:100vh;
	width: 100%;
}


header {
	background: #000;
	opacity: 0.5;

}
.text-presentation {
	background: #000;
	opacity: 0.5;
	border-radius: 2px;
}

footer {
	background: #000;
	opacity: 0.5;
	height: 100px;
	position: absolute;
	bottom: 0px;
	width:100%;
}


@media (max-width: 768px) { 


footer {
	background: #000;
	opacity: 0.5;
	height: 100px;
	position: relative;
	bottom: 0px;
	width:100%;
}


 }