* {
	margin: 0;
	padding: 0;
	box-sizing: border-box;
}

body {
	font-family: sans-serif;
	font-optical-sizing: auto;
	font-weight: normal;
	font-style: normal;
	font-size: 16px;
	width: 100%;
	max-width: 640px;
	margin: 0 auto;
	padding: 0;
	background-color: #eee;
	letter-spacing: -0.025em;
}
.ad-box {
	z-index: 0;
	margin: 20px 0;
	background-color: #f7f7f7;
}
.ad-box-in {
	z-index: 0;
	margin: 20px -10px;
	background-color: #f7f7f7;
}
.ad-box,
.ad-box-in {
	position: relative;
}

.ad-box .ad-sizer {
	height: 400px;
}
.ad-box-in .ad-sizer {
	height: 280px;
}
.ad-box > ins,
.ad-box-in > ins {
	position: absolute;
	top: 0;
	left: 50%;
	transform: translateX(-50%);
}
.ad-280 {
	width: 100%;
	min-height: 280px;
}

@media screen and (min-width: 768px) {
	.ad-box,
	.ad-box-in {
		height: 280px;
		align-content: center;
		margin: 20px auto;
	}
	.ad-box .ad-sizer {
		height: 280px;
	}
	.ad-280 {
		height: 100%;
		width: 768px;
		height: 280px;
	}
}