.course {
    position: relative;
    margin: 0 auto;
    border: 1px solid rgb(228, 226, 226);
}

.content_body {
    position: relative;
    height: 280px;
    padding: 10px;
}

.course-left {
    height: 260px;
    width: 498px;
    float: left;
    overflow: hidden;
}

.img {
    width: 480px;
}

.course-center {
    float: left;
    width: 390px;
    height: 100%;
    /* border: 1px solid black; */
}

.course-right{
    padding: 20px;
    width: 220px;
    float: right;
    background-color: #eee;
    min-height:255px;
}

.headimg{
    border: #ddd 1px solid;
    border-radius: 50%;
}

.course-center>h3 {
    line-height: 36px;
}

.course-center span {
    height: 24px;
    display: inline-block;
    line-height: 24px;
    margin-top: 10px;
}

.course-con{
    width: 890px;
    border-right: #eee 1px solid;
    float: left;
}

.course-con-right{
    width: 255px;
    float: right;
}

.course-con-right h4{
    line-height: 36px;
    height:42px;
    padding-left: 20px;
    border-bottom: #ddd 1px solid;
}

.avatar_ul li{
    padding-left: 10px;
    padding-bottom: 5px;
    width: 22%;
    display: inline-block;
}

.avatar_ul li img{
    width: 40px;
    border-radius: 50%;
}

.course-con-top {
    height: 52px;
    border-bottom: 1px solid #ddd;
}

.course-active{
    border-bottom: 2px solid rgb(187, 24, 24);
    color: red;
}

.course-box{
    padding: 20px;
}

.course-con-top li {
    float: left;
    text-align: center;
    list-style: none;
    cursor: pointer;
    line-height: 50px;
    width: 108px;
}

.course-con-top li:hover {
    border-bottom: 2px solid rgb(187, 24, 24);
    color: red;
}

.cou1 .course-title {
    margin-left: 10px;
    margin-bottom: 10px;
    padding-left: 10px;
    font-size: 20px;
    font-weight: bold;
    border-left: 5px solid rgb(155, 16, 16);
    color: rgb(107, 107, 107);
    display: block;
}

.cou1-txt {
    text-indent: 3em;
    font-size: 16px;
    color: rgb(129, 129, 129);
    line-height: 36px;
    margin: 23px;
}

.cou1-title li{
    display: flex;
    padding: 10px 0;
}

.cou1-title li:hover {
    background-color: #eee;
    cursor: pointer;
}

.cou1-title span {
    margin-left: 20px;
    line-height: 30px;
}

.invite-img4 {
    width: 30px;
    margin-left: 165px;
}

.course-tj{
    padding: 10px 20px;
    border-top: 1px solid #ddd;
    border-bottom:1px solid #ddd;
}

.cour-con {
    height: 170px;
    display: flex;
}

.cour-con .invite-img3 {
    width: 60px;
    height: 60px;
    border: 1px solid gray;
    border-radius: 50%;
    background-color: rgb(161, 159, 159);
    margin: 13px;
}

.cour-con-img {
    width: 20px;
}

.invite-imgage {
    width: 55px;
    border: 1px solid gray;
    border-radius: 50%;
    background-color: rgb(161, 159, 159);
    margin-right: 15px;
}

.course-dropbtn {
    background-color: brown;
    color: #ffffff;
    padding: 16px;
    font-size: 16px;
    border: none;
    cursor: pointer;
}

.bbs_ul ul li{
    padding-top: 5px;
    padding-left: 10px;
    padding-right: 10px;
    width: 8%;
    text-align: center;
    border-radius: 3px;
    cursor: pointer;
}

.bbs_ul ul li.active{
    background-color: #990000;
    color:#fff;
}

.bbs_ul ul li.active a{
    background-color: #990000;
    color:#fff;
}

.es-share {
    position: relative;
    display: inline-block;
}