.f1Bg {width:100%;height:2600px;overflow:hidden;position:relative;}
.f1Box{width:1920px;height:2600px;position:absolute;left:50%;top:0;margin-left:-960px;}
.f1Box li{line-height:0;position:relative;}
.f1Box li,.f1Box li img{width:1920px;}
.f1Box li.ioc1,.f1Box li.ioc1 img{height:722px;}
.f1Box li.ioc2,.f1Box li.ioc2 img{height:654px;}
.f1Box li.ioc3,.f1Box li.ioc3 img{height:1224px;}
.f1Box li.ioc3 .btn{position:absolute;left:50%;margin-left:-320px;bottom:148px;}
.f1Box li.ioc3 .btn a{width:268px;height:68px;text-align:center;line-height:68px;font-size:30px;color:#257d95;border:#257d95 solid 1px;border-radius:50px;display:inline-block;}
.f1Box li.ioc3 .btn a.chat{color:#fff;background-color:#257d95;margin-right:100px;}
@media only screen and (max-width: 750px){
        .f1Bg {width:100%;height:auto;overflow:hidden;position:relative;}
        .f1Box{display:none;}
        .f1BoxWap{line-height:0;}
        .f1BoxWap li,.f1BoxWap li img{width:100%;}
        .f1BoxWap li.ioc3 .btn{width:4.5rem;position:absolute;left:50%;margin-left:0;transform:translateX(-50%);bottom:.5rem;display:inline-block;}
        .f1BoxWap li.ioc3 .btn a{float:left;width:2rem;height:.6rem;text-align:center;line-height:.6rem;font-size:.28rem;color:#257d95;border:#257d95 solid 1px;border-radius:.5rem;display:inline-block;}
        .f1BoxWap li.ioc3 .btn a.chat{color:#fff;background-color:#257d95;}
        .f1BoxWap li.ioc3 .btn a:nth-child(2){float:right;}
}