* {
	box-sizing: border-box;
}

body {
	display: flex;
	min-height: 100dvh;
	margin: 0;
	padding: 20px;

	align-items: center;
	justify-content: center;

	background-color: #f0f0f0;

	font-family: 'Verdana', 'IBM Plex Sans', 'Helvetica', sans-serif;
	font-size: 12px;
}

section.calendar {
	display: grid;
	min-width: 100px;
	min-height: 100px;
	aspect-ratio: 1 / 1;

	grid-template-rows: auto 1fr;
	align-items: center;

	background: url('/corner.svg'), #ffffff;
	background-position: bottom right;
	background-size: 0;
	background-repeat: no-repeat;
	overflow: hidden;

	border: 1px solid #000000;

	text-align: center;

	box-shadow:
		1px 1px 0 0 #ffffff,
		2px 2px 0 0 #000000,
		3px 3px 0 0 #ffffff,
		4px 4px 0 0 #000000,
		5px 5px 0 0 #ffffff,
		6px 6px 0 0 #000000,
		11px 11px 0 0 #d2d2d2;

	transition: background-size 0.05s ease-in-out;
}

section.calendar:hover {
	background-size: 10px;	background-size: 5px;
}

section.calendar > header {
	padding: 5px;

	background-color: #d9dbff;

	border-bottom: 1px solid #000000;

	font-style: italic;
}

section.calendar > div.date {
	font-size: 32px;
	font-weight: bold;
}

section.calendar > div.date > span#suffix {
	font-size: 50%;
	vertical-align: super;
}