:root{
    --ColorA: pink;
    --ColorB: purple;
}

.sunset {
	background: linear-gradient(45deg, var(--ColorA) 2%, var(--ColorB));
	margin: 0px;
	animation: gradient 35s linear infinite;
	background-size: 180% 180%;
	height: 100vh;
	width: 100vw;
	position: fixed;
	z-index: -1;
	top:0;
	left:0;
}

@keyframes gradient {
	0% {
		background-position: 0% 50%;
	}

	50% {
		background-position: 100% 50%;
	}

	100% {
		background-position: 0% 50%;
	}