.content{
    width: 90%;
    max-width: 1200px;
    margin: auto;
}
.pl35{ padding-left: 35px;}
.case_title{ padding: 40px 15px 0 15px;}
.f16{ font-size: 16px;}
.case_tip li{ float: left; padding: 2px 5px; margin: 20px 15px;}
.case_tip li.current{ background: #ff6c6c;}
.case_tip li.current a{ color: #fff;}
.cases_div{ width: 100%; background: #efefef;}
.cases_list li{ width: 31%; padding: 30px 1%; float: left;}
.cases_list li .img_div{ width:90%; position: relative; }
.cases_list li .img_1div span{ display: none; width: 72.4%; height: 73.5%; padding: 0.5%; position: absolute; left: 13.3%; top: 8%; color: #fff; background:url("../images/cases_intro_bg.png") repeat; overflow: hidden;  }
@media screen and (max-width: 1024px){
    .pl35{ padding-left: 5%;}
}
@media screen and (max-width: 640px){
    .case_tip li{ margin: 15px 10px;}
    .cases_list li{ width: 48%; padding: 20px 1%; float: left;}
}
@media screen and (max-width: 400px){
    .case_title{ padding: 20px 0 10px 0;}
    .case_title img{ width: 70%;}
    .case_tip li{ margin:10px 0; font-size: 14px;}
    .cases_list li{ width: 98%; padding: 20px 1%; float: left;}
    .cases_list li .img_div{ width:100%; }
}