body {
  background-image: radial-gradient(circle at center, #5ae, #5d9, #7c6, #f44);
}
body::before {
	content: "";
	position: absolute;
	z-index: -1;
	inset: 0;
	background-image: radial-gradient(circle at center, #e74, #ae8, #7fd, #4ef);
	opacity: 0;
	transition: opacity 2s linear;
}
body:has(.menu:hover)::before {
	opacity: 1;
}

.paper {
    box-shadow: 0 0 20px #444;
}

/*h1, p {*/
/*  background-color: #ffeeee;*/
/*  padding: 20px;*/
/*}*/