CSS3画一个阴阳八卦图

<!-- HTML -->
<div id="yin_yang"></div>

#yin_yang {
	width: 96px;
	height: 48px;
	background: #eee;
	border-color: red;
	border-style: solid;
	border-width: 2px 2px 50px 2px;
	border-radius: 100%;
	position: relative;
}

#yin_yang:before {
	content: "";
	position: absolute;
	top: 50%;
	left: 0;
	background: #eee;
	border: 18px solid red;
	border-radius: 100%;
	width: 12px;
	height: 12px;
}

#yin_yang:after {
	content: "";
	position: absolute;
	top: 50%;
	left: 50%;
	background: red;
	border: 18px solid #eee;
	border-radius: 100%;
	width: 12px;
	height: 12px;
}