<div></div>

div {
	width: 380px;
	height: 380px;
	background: 
		repeating-linear-gradient(
			to right,
			transparent,
			transparent 50px,
			white 50px,
			white 55px
		),
		repeating-linear-gradient(
			to bottom,
			transparent,
			transparent 50px,
			white 50px,
			white 55px
		),
		linear-gradient(45deg, pink, skyblue);
}

body {
	display: grid;
	width: 100vw;
	height: 100vh;
	align-items: center;
	justify-items: center;
	margin: 0;
}