html {
	font-size: 62.5%;
}
body {
	margin: 0;
	font-size: 1.5rem;
}
p {
	margin: 0 0 1em;
}
*, *::before, *::after {
	box-sizing: border-box;
	margin: 0;
	padding: 0;
}
.contents {
	max-width: 630px;
	margin: 0 auto;
	padding: 20px;
	background: #f2f2f2;
}
.title {
	margin: 0 0 1em;
	font-weight: bold;
}

.div-parent {
	position: relative;
	width: 100%;
	height: 148px;
	margin: 0 0 1em;
	background-color: #fff;
}
.div-parent::before {
	content: "";
	position: absolute;
	top: 0;
	left: 0;
	display: inline-block;
	width: 100%;
	height: 100%;
	background-size: 40px 40px;
}
.style01::before {
	background-image: linear-gradient(90deg, #e1e2ed 1px, transparent 1px), linear-gradient(#e1e2ed 1px, transparent 1px);
}
.style02::before {
	background-image: linear-gradient(45deg, #e1e2ed 25%, transparent 25%, transparent 75%, #e1e2ed 75%), linear-gradient(45deg, #e1e2ed 25%, transparent 25%, transparent 75%, #e1e2ed 75%);
	background-position: 0 0, 20px 20px;
}
.style03::before {
	background-image: linear-gradient(45deg, #e1e2ed 25%, transparent 25%, transparent 75%, #e1e2ed 75%), linear-gradient(45deg, #e1e2ed 25%, transparent 25%, transparent 75%, #e1e2ed 75%);
	background-size: 80px 80px;
	background-position: 0 0, 40px 40px;
}

.copyright {
	text-align: center;
	padding-top: 2em;
	font-size: 14px;
}