body {
    margin: 0 auto;
    font-family:微软雅黑;
    overflow:scroll;
}
tr{font-size:13px;}
input[type=checkbox]{height:1.2em;width:1.2em;}
#subNav{padding:3px;position:relative;top:-12px;background:#555555;color:white;border:1px solid #555555;}
#subNav span{cursor:pointer;border:1px solid #555555;}
.activeNav{
    background:white;
    color:black;
    border:1px solid #555555;
}
.A{color:#000000;}
.B{color:#000000;}
.C{color:#aaaaaa;}
.sorted{color:#000000}
.sort{color:#bbbbbb;cursor:pointer;}
.extraLesson{background:#f6eee4;}
.textTitle{padding-left:40px;font-size:20px;}
.btn-danger{background: #b47f7f;border-color: #b47f7f}
.btn-success{background: #79ad7a;border-color: #79ad7a}
.btn-warning{background: #d0c75f;border-color: #d0c75f}
.demopicDiv{margin:20px;border:60px solid #dddddd;}