.case-nav{
    width: 100%;
    height: 120px;
    background: #F7F7F7;
    padding-top: 35px;
}
.case-nav .content{
    width: 1020px;
}
.case-nav .content .item{
    float: left;
    width: 170px;
    height: 50px;
    display: block;
    font-size:14px;
    font-family:Source Han Sans CN;
    font-weight:400;
    color:rgba(38,38,38,1);
    text-align: center;
    line-height: 50px;
}
.case-nav .content .item.on,.case-nav .content .item:hover{
    background: #E62129;
    border-radius: 50px;
    color: #fff;
}

.index-case{
    width: 100%;
    overflow: hidden;
    margin-top: 50px;
}
.index-case .content{
    margin-bottom: -20px;
}
.index-case .content .item{
    width: 285px;
    height: 280px;
    float: left;
    margin-right: 20px;
    position: relative;
    transition-duration: .3s;
    margin-bottom: 20px;
}
.index-case .content .item:nth-of-type(4n){
    margin-right: 0;
}
.index-case .content .item .imgBox{
    width: 285px;
    height: 220px;
    position: relative;
}
.index-case .content .item .imgBox img{
    width: 100%;
    height: auto;
}
.index-case .content .item .imgBox .mask{
    width: 100%;
    height: 100%;
    background: rgba(255,255,255,0.4);
    position: absolute;
    opacity: 0;
    top: 0;
    left: 0;
}
.index-case .content .item .wordsBox{
    width: 100%;
    height: 60px;
    position: absolute;
    left: 0;
    bottom: 0;
    background: #fff;
    overflow: hidden;
    transition-duration: .3s;
}
.index-case .content .item .wordsBox h2{
    font-size:16px;
    font-family:Source Han Sans CN;
    font-weight:400;
    color:rgba(38,38,38,1);
    text-align: center;
    line-height: 60px;
}
.index-case .content .item .wordsBox p{
    font-size:12px;
    font-family:Source Han Sans CN;
    font-weight:400;
    color:rgba(255,255,255,1);
    text-align: center;
    display: block;
    width: 57px;
    height: 57px;
    line-height: 57px;
    background: url("../images/icb.png") no-repeat;
    margin: 0 auto;
    transition-duration: .3s;
}
.index-case .content .item:hover{
    box-shadow: 0px 0px 20px 0px rgba(0,0,0,0.2);
}
.index-case .content .item:hover .imgBox .mask{
    opacity: 1;
}
.index-case .content .item:hover .wordsBox{
    height: 110px;
    background: #E62129;
}
.index-case .content .item:hover .wordsBox h2{
    color: #fff;
}
.index-case .content .item:hover .wordsBox p{
    margin-top: -15px;
}