css3背景透明

<style type="text/css"><!--
    .body{ background:#9F3;}
    .container{background:#000; width:293px;  background:rgba(0,0,0,0.4); filter:alpha(opacity=40);-webkit-box-shadow:2px 2px 6px #ccc;-moz-box-shadow:2px 2px 6px #ccc;}
    .container .sub_con{ position:relative; color:#fff; width:100%;}
--></style>
<div class="body">
<div class="container">
<div class="sub_con">流浪是好人，好人，一定是好人</div>
</div>
<br /><br /><br />
</div>