css制作圆角的原理及方法
关键词：用css制作圆角，全css代码制作圆角，不含图片的css制作圆角的方法
制作原理：其实很简单，圆角它是靠1px的高度来拼起来的，就像我们用长度不一，高为1px的直线一条一条的叠起来达到预期效果，圆角它是占用了一定的高度空间的，如果你画的圆角比较大的话，它需要的在垂直方向的线条就越多，就像堆木条一样。如果你在dreamweaver的设计视图下，你把鼠标移动到圆角那里，稍微上下移动，你就可以感觉到圆角原来也是一些直线而已，只不过它们长短的不一，看起来就像圆角而已。可以说这是CSS的一些小技巧。
方法：
样式1：简洁型css圆角矩形
<style>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;}
</style>
<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">
<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>
</body>
样式2：3D效果css圆角矩形
<style>
.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:1px solid #eee;}
.raised .b3{background:#ccc;border-left:1px solid #fff;border-right:1px solid #ddd;}
.raised .b4{background:#ccc;border-left:1px solid #fff;border-right:1px solid #aaa;}
.raised .b4b{background:#ccc;border-left:1px solid #eee;border-right:1px solid #999;}
.raised .b3b{background:#ccc;border-left:1px solid #ddd;border-right:1px solid #999;}
.raised .b2b{background:#ccc;border-left:1px solid #aaa;border-right:1px solid #999;}
.raised .b1{margin:0 5px;background:#fff;}
.raised .b2, .raised .b2b{margin:0 3px;border-width:0 2px;}
.raised .b3, .raised .b3b{margin:0 2px;}
.raised .b4, .raised .b4b{height:2px; margin:0 1px;}
.raised .b1b{margin:0 5px; background:#999;}
.raised .boxcontent{display:block;background:#ccc;border-left:1px solid #fff;border-right:1px solid #999;}
</style>
<body>
<div class="raised">
<b class="b1"></b><b class="b2"></b><b class="b3"></b><b class="b4"></b>
<div class="boxcontent">
<h1>3D圆角矩形</h1>
</div>
<b class="b4b"></b><b class="b3b"></b><b class="b2b"></b><b class="b1b"></b>
</div>
</body>
样式3：略带菱形的css圆角矩形
<style>
.curved {background:transparent; width:40%;}
.curved h1, .curved p { margin:0 10px;}
.curved h1 { font-size:2em;color:#fff;}
.curved p {padding-bottom:0.5em;}
.curved .b1, .curved .b2, .curved .b3, .curved .b4 {display:block;overflow:hidden;height:1px;font-size:1px;}
.curved .b2, .curved .b3, .curved .b4 {background:#e0cea3;border-left:1px solid #fff;border-right:1px solid #fff;}
.curved .b1 {margin:0 4px;background:#fff;}
.curved .b2 {margin:0 4px; height:2px;}
.curved .b3 {margin:0 3px;}
.curved .b4 {margin:0;height:1px;border-width:0 3px 0 3px;}
.curved .boxcontent {display:block;background:#e0cea3;border:0 solid #fff;border-width:0 1px;}
</style>
<body>
<div class="curved">
<b class="b1"></b><b class="b2"></b><b class="b3"></b><b class="b4"></b>
<div class="boxcontent">
<h1>略带菱形的css圆角矩形</h1>
</div>
<b class="b4"></b><b class="b3"></b><b class="b2"></b><b class="b1"></b>
</div>
</body>
样式4 特殊css圆角矩形
<style>
.pillar {background:transparent;width:40%;}
.pillar h1, .pillar p {margin:0 10px;}
.pillar h1 {font-size:2em;color:#fff;}
.pillar p {padding-bottom:0.5em;}
.pillar .b1, .pillar .b2, .pillar .b3, .pillar .b4 {display:block;overflow:hidden;font-size:1px;}
.pillar .b1, .pillar .b2, .pillar .b4 {height:1px;}
.pillar .b2, .pillar .b3 {background:#d66;border-left:1px solid #fff;border-right:1px solid #fff;}
.pillar .b4 {background:#d66;border-left:4px solid #fff;border-right:4px solid #fff;}
.pillar .b1 {margin:0 2px;background:#fff;}
.pillar .b2 {margin:0 1px;border-width:0 1px;}
.pillar .b3 {height:2px;margin:0;}
.pillar .b4 {margin:0 2px;}
.pillar .boxcontent {display:block;background:#d66;border-left:1px solid #fff;border-right:1px solid #fff;margin:0 5px;}
</style>
<body>
<div class="pillar">
<b class="b1"></b><b class="b2"></b><b class="b3"></b><b class="b2"></b><b class="b4"></b>
<div class="boxcontent">
<h1>特殊css圆角矩形</h1>
</div>
<b class="b4"></b><b class="b2"></b><b class="b3"></b><b class="b2"></b><b class="b1"></b>
</div>
</body>
样式5 ：反向css圆角矩形
<style>
.serif {background: transparent; width:40%;}
.serif h1, .serif p {margin:0 10px;}
.serif h1 {font-size:2em; color:#fff;}
.serif p {padding-bottom:0.5em;}
.serif .b1, .serif .b2, .serif .b3, .serif .b4 {display:block;overflow:hidden;font-size:1px;}
.serif .b1, .serif .b2, .serif .b3 {height:1px;}
.serif .b2, .serif .b3 {background:#fc0;border-left:1px solid #fff;border-right:1px solid #fff;}
.serif .b4 {background:#fc0;border-left:1px solid #fff;border-right:1px solid #fff;}
.serif .b1 {margin:0; background:#fff;}
.serif .b2 {margin:0 1px;border-width:0 2px;}
.serif .b3 {margin:0 3px;}
.serif .b4 {height:2px;margin:0 4px;}
.serif .boxcontent {display:block; background:#fc0;border-left:1px solid #fff;border-right:1px solid #fff;margin:0 5px;}
</style>
<body>
<div class="serif">
<b class="b1"></b><b class="b2"></b><b class="b3"></b><b class="b4"></b>
<div class="boxcontent">
<h1>反向css圆角矩形</h1>
</div>
<b class="b4"></b><b class="b3"></b><b class="b2"></b><b class="b1"></b>
</div>
</body>