html, body {
	height: 100%;
}

@media (max-height: 650px) {
	html, body {
		height: auto;
	}
}

main {
    display: flex;
    align-items: center;
    justify-content: center;
    height: 100%;
}

.visitenkarte {
	max-width: 100%;
	max-height: 100%;	
	min-width: 350px;
	min-height: 200px;
}