* {
    margin: 0;
    padding: 0;
    font-family: "microsoft yahei";
}
img {
    border: none;
}
a {
    text-decoration: none;
}
ol, ul {
    list-style: none;
}
div {
    display: block;
}
.w1200 {
    width: 100%;
    margin: 0 auto 0 auto;
    position: relative;
}
.case_box {
    background: url(../images/case_bg.jpg) no-repeat center top;
    height: 620px;
}

.case_box .category ul {
    width:540px;
    padding-bottom: 10px;
    display: block;
    height: auto;
    overflow: hidden;
    margin:0 auto 0 auto;
}
.case_box .category ul li {
    float: left;
    font-size: 18px;
    text-align: center;
    width: 180px;
    height: 48px;
    line-height: 48px;
    color: #939aac;
    border-radius: 5px;
    cursor: pointer;
}
.case_box .category ul li.active {
    color: #fff;
    background: #4f77fc;
}
.case_box .content {
    padding-left: 0px;
}
.case_box .content .cont {
    height: 650px;
    display: none;
}
.case_box .content .cont.active {
    display: block;    
}