.case_ul{
    width: 100%;
}
.case_ul li{
    width: 23.4%;
    float: left;
    box-sizing: border-box;
    margin:10px ;
}
.case_ul li img{
    width: 100%;
    height: 180px;
}

.case_ul li a{
    text-align: center;
    display: inline-block;
    width: 100%;
    height: 35px;
    line-height: 35px;
    background: #009049;
    color: #fff;
    margin-top: 5px;
}
.case_ul li a:hover{
    background: #333;
}