园角框或背景的css方法

<style type="text/css">
/*===设置圆角层*/
.line div {height: 1px;overflow: hidden; }
div.s1 {margin: 0 4px;background-color:#000;}
div.s2 {margin: 0 3px;background-color:#eee;border-left:1px #000 solid;border-right:1px #000 solid;}
div.s3 {margin: 0 2px;background-color:#eee;border-left:1px #000 solid;border-right:1px #000 solid;}
div.s4 {margin: 0 1px;height: 2px;background-color:#eee;border-left:1px #000 solid;border-right:1px #000 solid;}
/*===设置内容层*/
.content {
padding:0 10px;
background-color:#fff;
border-left:1px #000 solid;border-right:1px #000 solid;
}
/*===设置sloths层及颜色*/
#sloths {
width:560px;
margin:10px auto;
overflow:hidden;
}
</style>
<!-- sloth -->
<div id="sloths">
<div class="line">
   <div class="s1"></div>
   <div class="s2"></div>
   <div class="s3"></div>
   <div class="s4"></div>
   </div>
   <div class="content">
    sadfas
   </div>
   <div class="line">
   <div class="s4"></div>
   <div class="s3"></div>
   <div class="s2"></div>
   <div class="s1">
</div>
</div>
</div>
<!-- sloths over -->