.case-right .successful-case{position: relative;  height: 307px;}
.case-right .successful-case:hover img{opacity: 0.8;}
.case-right .successful-case:hover .showcase{opacity: 0.9;}
.case-right .successful-case:hover .tab_btn{display:block;}
.case-right .successful-case .tab_btn{display:none;position: absolute; background: url(../img/tab_btn.png) no-repeat;width: 35px;height: 35px;cursor: pointer;opacity: 1;}
.case-right .successful-case .tab_left{background-position: 0 0;  left: 15px;top: 156px;}
.case-right .successful-case .tab_right{background-position:-40px 0 ;right: 15px;top: 156px;}
.case-right .successful-case .tab_length{width: inherit;position: absolute;bottom: 14px;text-align: center;}
.case-right .successful-case .tab_length span{display: inline-block;background: url(../img/tab_btn.png) no-repeat 0 -40px; width: 10px;height: 10px;margin-right: 7px;cursor: pointer;}
.case-right .successful-case .tab_length .btn_selected{background-position: -22px -40px;}
.successful-case  .showcase{ position: absolute;left: 0;bottom: 0;width: 9999px;}
.successful-case  .showcase li{position: relative;float: left;}