.video_nav_box{
    width: 100%;
    background:rgba(249,249,249,1);
    margin-top: 82px;
    overflow: hidden;
    padding-top: 13px;
    padding-bottom: 13px;
}
.video_nav h2{
    font-size: 20px;
    color:rgba(153,153,153,1);
}
.video_nav ul{
    width: 150%;
    color: #000000;
    font-size:16px;
    overflow: hidden;
}
.video_t{
    font-size: 25px;
    display: inline-block;
    position: relative;

}
.video_t:after{
    content: '';
    width: 50%;
    height: 3px;
    background:rgba(112,192,144,1);
    position: absolute;
    left: 50%;
    -webkit-transform: translateX(-50%);
    -moz-transform: translateX(-50%);
    -ms-transform: translateX(-50%);
    -o-transform: translateX(-50%);
    transform: translateX(-50%);
    bottom: 0px;
}
.video_nav ul li{
    float: left;
    width: 220px;
    margin-right: 5%;
    -webkit-transition: all .4s;
    -moz-transition: all .4s;
    -ms-transition: all .4s;
    -o-transition: all .4s;
    transition: all .4s;
}
.video_nav ul li:hover{
    cursor: pointer;
    color:rgba(0,144,179,1);
}
.video_list{
    margin-top: 20px;
    margin-bottom: 30px;
}
.video_list ul{
    width: 100%;
    margin-top: 20px;
    overflow: hidden;
}
.video_list ul li{
    width: 15.8%;
    min-height: 150px;
    background: rgba(248,248,248,1);
    float: left;
    overflow: hidden;
    margin-right: .5%;
    margin-top: 10px;
}
.video_list ul li:hover{
    cursor: pointer;
}
.video_list ul li img{
    width: 100%;
    height: 130px;
}
.video_list ul li dt{
    color:rgba(0,0,0,1);
    font-size: 16px;
    margin-bottom: 3px;
}
.video_list ul li dd{
    color:rgba(109,109,109,1);
}
.video_list ul li dl{
    padding: 10px;
}
.search_box{
    width: 100%;
    overflow: hidden;
}
.search_main{
    display: inline-block;
    width:260px;
    height:30px;
    background:transparent;
    border-radius:10px;
    border:1px solid rgba(0,144,179,1);
    line-height: 38px;
    overflow: hidden;
    position: relative;
    float: right;
    top: 12px;
    margin-right: 2.6%;
}
.search_main input{
    background:transparent;
    width: 70%;
    height: 100%;
    border: none;
    line-height: 30px;
    margin-left: 5%;
    float: left;
}
.search_main a img {
    height:15px;
}
.search_main a{
    margin-right: 10px;
    float: right;
    position: relative;
    top: 50%;
    -webkit-transform: translateY(-50%);
    -moz-transform: translateY(-50%);
    -ms-transform: translateY(-50%);
    -o-transform: translateY(-50%);
    transform: translateY(-50%);
}
.mark-box{
    width: 100vw;
    height: 100vh;
    background: rgba(0,0,0,.6);
    position: fixed;
    top: 0;
    left: 0;
    z-index: 9999;
}
.mark_main{
    width: 750px;
    height: 500px;
    top: 40%;
    left: 50%;
    position: absolute;
    -webkit-transform: translate(-50%,-50%);
    -moz-transform: translate(-50%,-50%);
    -ms-transform: translate(-50%,-50%);
    -o-transform: translate(-50%,-50%);
    transform: translate(-50%,-50%);
}
.mark_main h2{
    width: 100%;
    height: 30px;
    background: #d4d4d4;
    text-align: center;
}
.close{
    background: #d4d4d4;
    width: 30px;
    height: 30px;
    top: 0;
    right: 0px;
}
.close hr{
    background: #000;
}
.close:hover{
    opacity: .8;
}
.close:hover hr{
    background: #000;
}
.back{
    float: right;
    display: inline-block;
    height: 100%;
    background: rgba(0,144,179,1);
    text-align: center;
    width: 80px;
    position: relative;
    top: 15px;
    border-radius: 5px;
    color: white;
    margin-right: 10px;
}
.back:hover{
    cursor: pointer;
}