@keyframes sunrise {
	from{background-position: 0% 0%}
	to{background-position: 100% 100%;}
}

body {
	background-image: linear-gradient(135deg, darkred, darkorange, yellow, darkgreen, darkblue, purple);
	background-size: 1200% 1200%;
	animation: 15s sunrise infinite ease alternate;
}

html, body {
    margin: 0;
    height: 100vh;
}