.info {
	margin: 20px auto;
	text-align: center;
	max-width: 660px;
}
.arena {
	position: relative;
	width: 750px;
	height: 500px;
	background: #ffffff;
	border: #ffcccc 1px solid;
	margin: 20px auto;
}
.arena div {
	position: absolute;
	width: 10px;
	height: 10px;
	cursor: pointer;
	line-height: 0;
	font-size: 0;
	background: url('tile.png');
}