CSS:
.item_bg {
background:#000;
opacity: .75; /* 标准: firefox 1.5+, opera, safari,chrome */
-ms-filter: “alpha(opacity=75)”; /* ie 8 */
filter: alpha(opacity=75); /* ie7- */
-khtml-opacity: .75; /* safari 1.x */
-moz-opacity: .75; /* firefox 1.5-, netscape */
}
HTML:
<div class=”item”> <!--外层容器-->
<div class=”item-bg”></div> <!--背景层-->
<div class=”item-con”> <!--内容层-->
content...
</div>
</div>