body {
	background:
	linear-gradient(
		limegreen,
		transparent
	),
	linear-gradient(
		90deg,
		skyblue,
		transparent
	),
	linear-gradient(
		-90deg,
		coral,
		transparent
	);
	background-blend-mode: screen;
	background-attachment:fixed;
}
body::before {
  content: "";
  position: fixed;
  top: -10px;
  left: 0;
  width: 100%;
  height: 10px;
  box-shadow: 0 0 10px rgba(0, 0, 0, 0.8);
  z-index: 100;
}