html , body {
	font-family: Helvetica;
	margin: 0; 
	padding: 0;
	width:100%;
	height:100%;
}
header{
	position:fixed;
	top:0px;
	left:0px;
	width:100%;	
	background-color:white;
	z-index:1;
}
header h1{
	text-align:center;
}
main{	
	width:100%;	
	top:40%;
	height:auto;
	position:relative;
}
footer{
	position:fixed;
	bottom:0px;
	left:0px;
	height:10%;
	width:100%;	
	background-color:white;
}
footer center{
	position:absolute;
	right:0px;
	left:0px;
	margin:auto;
	
	top: 50%;
	transform: translateY(-50%);
	
}