效果图：
<!DOCTYPE html>
<html lang="en" dir="ltr">
<head>
<meta charset="utf-8">
<title></title>
<style media="screen">
html,body {
height: 100%;
margin: 0px;
}
body {
background-image: url(http://b-ssl.duitang.com/uploads/blog/201406/28/20140628160330_r2RsB.jpeg);
background-attachment: fixed;
background-position: center;
background-size: cover;
position: relative;
}
// 核心css -- 依据父级容器的背景效果实现毛玻璃
.wrap {
width: 100%;
height: 200px;
position: relative;
background: inherit;
box-shadow: 0px 0px 8px #333;
border-radius: 5px;
z-index: 0;
}
// 模糊效果
.wrap::before {
content: '';
position: absolute;
top:0;
right: 0;
bottom: 0;
left: 0;
background: inherit;
background-attachment: fixed;
filter: blur(5px);
z-index: -1;
}
// 增加透明度的白底 -- 非必要
.wrap::after {
content: '';
position: absolute;
top:0;
right: 0;
bottom: 0;
left: 0;
background: rgba(255,255,255,.35);
z-index: -1;
}
</style>
</head>
<body>
<div class="wrap">
<span style="padding: 60px;display: inline-block;">玻璃模糊效果... ...</span>
</div>
</body>
</html>