☀【圆角】

<!DOCTYPE html>
<html lang="zh-CN">
<head>
    <meta charset="utf-8">
    <title></title>
    <style type="text/css">
        #box {
            width: 300px;
        }
        b {
            display: block;
        }
        .b1,
        .b2,
        .b3,
        .b4 {
            overflow: hidden;
            height: 1px;
            border-left: 1px solid #000;
            border-right: 1px solid #000;
        }
        .b1 {
            margin: 0 5px;
            background: #000;
        }
        .b2 {
            margin: 0 3px;
            border-width: 0 2px;
        }
        .b3 {
            margin: 0 2px;
        }
        .b4 {
            height: 2px;
            margin: 0 1px;
        }
        #content {
            border: solid #000;
            border-width: 0 1px;
            height: 100px;
        }
    </style>
</head>
<body>
    <div id="box">
        <b class="top">
            <b class="b1"></b>
            <b class="b2"></b>
            <b class="b3"></b>
            <b class="b4"></b>
        </b>
        <div id="content">内容区</div>
        <b class="bottom">
            <b class="b4"></b>
            <b class="b3"></b>
            <b class="b2"></b>
            <b class="b1"></b>
        </b>
    </div>
</body>
</html>

<!DOCTYPE html>
<html lang="zh-CN">
<head>
    <meta charset="utf-8">
    <title></title>
    <style type="text/css">
        #nifty {
            width: 300px;
        }
        #con {
            height: 100px;
        }
        #nifty,
        .rtop div {
            background: #9bd1fa;
        }
        .rtop {
            background: #fff;
        }
        .rtop div {
            height: 1px;
            overflow: hidden;
        }
        .r1 {
            margin: 0 5px;
        }
        .r2 {
            margin: 0 3px;
        }
        .r3 {
            margin: 0 2px;
        }
        .r4 {
            margin: 0 1px;
            height: 2px;
        }
    </style>
</head>
<body>
    <div id="nifty">
        <div class="rtop">
            <div class="r1"></div>
            <div class="r2"></div>
            <div class="r3"></div>
            <div class="r4"></div>
        </div>
        <div id="con"></div>
        <div class="rtop">
            <div class="r4"></div>
            <div class="r3"></div>
            <div class="r2"></div>
            <div class="r1"></div>
        </div>
    </div>
</body>
</html>

<!DOCTYPE html>
<html lang="zh-CN">
<head>
    <meta charset="utf-8">
    <title></title>
    <style type="text/css">
        * {
            margin: 0;
            padding: 0;
        }
        .box {
            width: 400px;
            margin: 20px auto;
        }
        h1 {
            font-size: 2em;
            color: #fff;
            padding: 20px;
            text-align: center;
        }
        b {
            display: block;
            overflow: hidden;
            height: 1px;
            background: #96C2F1;
            border-width: 0 1px;
            border-style: solid;
        }
        .b1 {
            margin: 0 5px;
            background: #fff;
            border: none;
        }
        .b2 {
            border-right: #eee;
        }
        .b3 {
            border-right: #ddd;
        }
        .b4 {
            border-right: #aaa;
        }
        .b4b {
            border-left: #eee;
        }
        .b3b {
            border-left: #ddd;
        }
        .b2b {
            border-left: #aaa;
        }
        .b2,
        .b3,
        .b4 {
            border-left-color: #fff;
        }
        .b4b,
        .b3b,
        .b2b {
            border-right-color: #999;
        }
        .b2,
        .b2b {
            margin: 0 3px;
            border-width: 0 2px;
        }
        .b3,
        .b3b {
            margin: 0 2px;
        }
        .b4,
        .b4b {
            height: 2px;
            margin: 0 1px;
        }
        .b1b {
            margin: 0 5px;
            background: #999;
            border: none;
        }
        .content {
            background: #96C2F1;
            border-left: 1px solid #fff;
            border-right: 1px solid #999;
        }
    </style>
</head>
<body>
    <div class="box">
        <b class="b1"></b>
        <b class="b2"></b>
        <b class="b3"></b>
        <b class="b4"></b>
        <div class="content">
            <h1>3D效果CSS圆角</h1>
        </div>
        <b class="b4b"></b>
        <b class="b3b"></b>
        <b class="b2b"></b>
        <b class="b1b"></b>
    </div>
</body>
</html>

<!doctype html>
<html lang="zh-CN">
<head>
    <meta charset="utf-8">
    <title></title>
    <style>
        body,
        img,
        b {
            margin: 0;
            padding: 0;
        }
        img {
            border: none;
        }
        .radius {
            display: inline-block;
            position: relative;
            overflow: hidden;
        }
        .radius b {
            position: absolute;
            top: 0;
            left: 0;
            background: url(radius.png) no-repeat;
        }
        .radius-77 {
            width: 77px;
            height: 77px;
        }
        .radius-77 img {
            -ms-border-radius: 10px;
            -moz-border-radius: 10px;
            -webkit-border-radius: 10px;
            border-radius: 10px;
        }
        .radius-77 b {
            width: 77px;
            height: 77px;
            background-position: 0 0;
        }
        .radius-16 {
            width: 16px;
            height: 16px;
        }
        .radius-16 img {
            -ms-border-radius: 2px;
            -moz-border-radius: 2px;
            -webkit-border-radius: 2px;
            border-radius: 2px;
        }
        .radius-16 b {
            width: 16px;
            height: 16px;
            background-position: 0 -78px;
        }
    </style>
</head>
<body>
    <span class="radius radius-77">
        <img src="http://pic.29293.com/pic/5414639382564497756.jpg" width="77" height="77" alt="">
        <!--[if lte IE 8]><b></b><![endif]-->
    </span>
    <span class="radius radius-16">
        <img src="http://pic.29293.com/pic/5414639382564497756.jpg" width="16" height="16" alt="">
        <!--[if lte IE 8]><b></b><![endif]-->
    </span>
</body>
</html>
原文地址:https://www.cnblogs.com/jzm17173/p/2590546.html