@media screen and (max-width: 768px) {
    .course_cont1_bg{
        padding: 0 20px;
        font-size: 16px;
    }
    .course_cont1_all, .course_cont1_new{
        font-size: 16px;
    }
    .course_mian{
        width: 100%;
        padding: 20px;
        margin: 0;
        overflow: hidden;
    }
    .news_cont_left{
        width: 100%;
        float: none;
    }
    .news_cont_right{
        display: none;
        float: none;
    }
    .news_cont_left li{
        width: 100%;
        height: auto;
        padding-bottom: 20px;
    }
    .news_cont_left li img{
        width: 100%;
        height: auto;
        float: none;
    }
    .course_left_list{
        float: none;
        width: 100%;
    }
    .news_left_title{
        width: 100%;
        margin: 10px 0px;
        font-size: 20px;
    }
}