html { 
  background: url(Hintergrund.jpg) no-repeat center center fixed; 
  -webkit-background-size: cover;
  -moz-background-size: cover;
  -o-background-size: cover;
  background-size: cover;
}
@media all and (min-width: 35em) {
	button {
		padding: 0.1em;
		width: 10em;
		height: 7.5em;
		position: relative;	
	}

	button img {
		border: 0;
		position: absolute;
		left: 0%;
		top: 0%;
		z-index: 1;
		box-shadow: 0;
		width: 10em;		
		transition: all 1s;			
	}

	button:focus img, 
	button:hover img {
		border: 2em solid #eee;
		border-radius: 1em;
		box-shadow: 1px 1px 5px #333;
		width: 300%;
		position: absolute;
		left: -4%;
		top: -4%;
		z-index: 5;

		transition: all 1s;		
	}	
}