不要背景图片造出的圆角背景的样式 _Web前端

不用背景图片造出的圆角背景的样式
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> 
<html xmlns="http://www.w3.org/1999/xhtml"> 
<head> 
    <meta http-equiv="Content-Type" content="text/html; charset=GB2312"/> 
<title></title>
<style type="text/css">
	html,body{
		font-size:12px;
	}
	.round_border,.round_border b{
		display:block;
		text-align:center;
	}
	.round_border_layer3,.round_border_layer2,.round_border_layer1,
	.round_border_content{
		border:1px solid #c4c4c4;
		border-width:0 1px 0 1px;
		height:1px;
		overflow:hidden;
	}
	.round_border_layer3{
		margin:0 3px;
		background:#c4c4c4;
	}
	.round_border_layer2{
		margin:0 2px;
	}
	.round_border_layer1{
		margin:0 1px;
	}
	.round_border_content{
		height:30px;
		padding:3px 6px;
	}
	/*only for better appearance, not necessary, http://wallimn.iteye.com*/
	.round_border_layer2,.round_border_layer1{
		border-color:#d3d4d5;
	}
	/*******************control bar**********************/
	.controlbar_border_layer3,.controlbar_border_layer2,.controlbar_border_layer1,
	.controlbar_border_content{
		background:#e9e9e9;
		height:1px;
		overflow:hidden;
	}
	.controlbar_border_layer3{
		margin:0 3px;
	}
	.controlbar_border_layer2{
		margin:0 2px;
	}
	.controlbar_border_layer1{
		margin:0 1px;
	}
	.controlbar_border_content{
		height:20px;
		padding:0 1em;
		line-height:20px;
		vertical-align:middle;
	}
	/*only for better appearance, not necessary, http://wallimn.iteye.com*/
	.controlbar_border_layer1,..controlbar_border_layer2{
		border-color:#f2f2f2;
	}
</style>
</head>
<body>
	<div style="width:260px;">
		<b class="round_border">
			<b class="round_border_layer3"></b>
			<b class="round_border_layer2"></b>
			<b class="round_border_layer1"></b>
		</b>
		<div class="round_border_content">
			<b class="round_border">
				<b class="controlbar_border_layer3"></b>
				<b class="controlbar_border_layer2"></b>
				<b class="controlbar_border_layer1"></b>
			</b>
			<div class="controlbar_border_content">
				隔壁老王
			</div>
			<b class="round_border">
				<b class="controlbar_border_layer1"></b>
				<b class="controlbar_border_layer2"></b>
				<b class="controlbar_border_layer3"></b>
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		</div>
		<div class="round_border_content">
			<b class="round_border">
				<b class="controlbar_border_layer3"></b>
				<b class="controlbar_border_layer2"></b>
				<b class="controlbar_border_layer1"></b>
			</b>
			<div class="controlbar_border_content">
				隔壁老王
			</div>
			<b class="round_border">
				<b class="controlbar_border_layer1"></b>
				<b class="controlbar_border_layer2"></b>
				<b class="controlbar_border_layer3"></b>
			</b>
		</div>
		<b class="round_border">
			<b class="round_border_layer1"></b>
			<b class="round_border_layer2"></b>
			<b class="round_border_layer3"></b>
		</b>
	</div>
</body>
</html>