.middle-box{
    border-radius: 5px;
    background: rgba(205, 225, 240, 0.1);
    padding: 20px;
}

.middle-box:hover{
    background: rgba(205, 225, 240, 0.15);
}

.logo {
    margin: 0 auto;
    width: 100%;
    height: 100%;
    background-color: #000;
    position: fixed;
}

.logo canvas {
    width: 100%;
    height: 100%; /*默认全屏显示 可自己设置高度640px*/;
    display: inline-block;
    vertical-align: baseline;
    position : fixed;
    z-index: -10;
}

.logo .canvaszz {
    /*用来解决视频右键菜单，用于视频上面的遮罩层*/
    width: 100%;
    background: url(../img/loginbg2.jpg) no-repeat fixed;
    background-size:cover;
    height: 100%;
    position: absolute;
    z-index: -20;
    filter: alpha(opacity=60);
    -moz-opacity: 0.6;
    -khtml-opacity: 0.6;
    opacity: 0.6;
}

.logo .top_logo {
    position: absolute;
    top: 80px;
    left:50%;
    margin-left:-150px;
    z-index: 30;

}

/*.logo .nav {
    height: auto;
    position: absolute;
    z-index: 30;
    top: 420px;
    left: 50%;
    margin-left: -400px;
}*/

.logo .nav .gv {
    text-decoration: none;
    background: url(../img/nav_gv.png) no-repeat 0 0;
    display: inline-block;
    width: 130px;
    height: 43px;
    margin:10px 0;
    text-align: center; /*水平居中*/
    line-height: 43px; /*上下居中*/
    cursor: pointer;
    font-size: 16px;
}

.logo .nav .gv span {
    display: none;

}

.logo .nav .gv:hover {
    background: url(../img/nav_gv.png) no-repeat 0 -43px;
    -webkit-box-shadow: 0 0 6px #1d7eb8;
    transition-duration: 0.5s;
}

.logo .topcn {
    width: 980px;
    top: 200px;
    left: 50%;
    margin-left: -490px;
    position: absolute;
    z-index: 20;
}