这是引用博客园前端LOVER的文章，请参见：DIV+CSS圆角边框
简洁型css圆角：
方法1：
code1:
<style type="text/css">
.b1,.b2,.b3,.b4,.b1b,.b2b,.b3b,.b4b,.b{display:block;overflow:hidden;}
.b1,.b2,.b3,.b1b,.b2b,.b3b{height:1px;}
.b2,.b3,.b4,.b2b,.b3b,.b4b,.b{border-left:1px solid #999;border-right:1px solid #999;}
.b1,.b1b{margin:0 5px;background:#999;}
.b2,.b2b{margin:0 3px;border-width:2px;}
.b3,.b3b{margin:0 2px;}
.b4,.b4b{height:2px;margin:0 1px;}
.d1{background:#F7F8F9;}
.k {height:300px;}
</style>
</head>
<body>
<div>
<b class="b1"></b><b class="b2 d1"></b><b class="b3 d1"></b><b class="b4 d1"></b>
<div class="b d1 k">
<font style="font-size:26px;color:red; margin:0px 10px;">简洁型css圆角矩形</font>
</div>
<b class="b4b d1"></b><b class="b3b d1"></b><b class="b2b d1"></b><b class="b1b"></b>
</div>
方法2：
无图片实现圆角框
code2:
<style type="text/css">
div.RoundedCorner{background:#9BD1FA; width:400px;}
b.rtop, b.rbottom{display:block;background: #FFF}
b.rtop b, b.rbottom b{display:block;height: 1px;overflow: hidden; background: #9BD1FA}
b.r1{margin: 0 5px}
b.r2{margin: 0 3px}
b.r3{margin: 0 2px}
b.rtop b.r4, b.rbottom b.r4{margin: 0 1px;height: 2px}
</style>
<div class="RoundedCorner">
<b class="rtop"><b class="r1"></b><b class="r2"></b><b class="r3"></b><b class="r4"></b></b>
<br>无图片实现圆角框<br><br>
<b class="rbottom"><b class="r4"></b><b class="r3"></b><b class="r2"></b><b class="r1"></b></b>
</div>
3D圆角矩形:
CODE:
<style type="text/css">
.raised{background:transparent;width:40%;}
.raised h1,.raised p{margin:0 10px;}
.raised h1{font-size:2em;color:#fff;}
.raised p{padding-bottom:0.5em;}
.raised .b1,.raised .b2,.raised .b3,.raised .b4,.raised .b1b,.raised .b2b,.raised .b3b,.raised .b4b{display:block;overflow:hidden;font-size:1px;}
.raised .b1,.raised .b2,.raised .b3,.raised .b1b,.raised .b2b,.raised .b3b{height:1px;}
.raised .b2{background:#ccc;border-left:1px solid #fff;border-right:
