body {
	min-height: 100vh;
	display: flex;
	align-items: center;
	justify-content: center;
	background: linear-gradient(135deg, var(--color-gray-400) 0%, var(--color-white) 45%, var(--color-gray-400) 100%);
	background-size: 220% 220%;
	padding: 20px;
	box-sizing: border-box;
	position: relative;
	overflow: hidden;
	animation: bg-shift 30s ease-in-out infinite;
}

body > * {
	position: relative;
	z-index: 1;
}

@keyframes bg-shift {
	0%   { background-position: 0% 50%; }
	50%  { background-position: 100% 50%; }
	100% { background-position: 0% 50%; }
}