@charset "UTF-8";
/****************专题学习 start****************/
.subject_banner {
    position:relative;
    width:100%;
    min-width:1280px;
    height:350px;
    overflow:hidden;
}
.subject_center{
    position:absolute;
    left:50%;
    transform: translate(-50%,0);
    width:1920px;
    height:350px;
    background:url(../images/subject_banner.jpg) no-repeat center;
    overflow:hidden;
}
#subject{
    margin:0 auto;
    overflow:hidden;
}
.subject_box{
    width:100%;
    background:#fff;
    border-radius:8px;
    margin-bottom:20px;
    overflow:hidden;
}
.subject_title{
    width:100%;
    line-height:60px;
    background:#c81215;
    padding:0 20px;
    margin:0 auto 15px;
    overflow:hidden;
    -webkit-box-sizing: border-box;
    -moz-box-sizing: border-box;
    box-sizing: border-box;
}
.subject_title h2{
    float:left;
    font-size:18px;
    color:#fff;
}
.subject_title h2 i{
    float:left;
    width:8px;
    height:24px;
    background:#f5f583;
    border-radius:10px;
    margin:18px 10px 0 0;
}
.subject_title a{
    float:right;
    font-size:14px;
    line-height:30px;
    padding:0 15px;
    border-radius:30px;
    border:2px solid #fff;
    color:#fff;
    transition:all .3s;
    margin:13px 0;
    overflow:hidden;
}
.subject_title a i{
    vertical-align: -1px;
}
.subject_title a:hover{
    padding:0 20px;
    background:#f5f583;
    border-color:#f5f583;
    color:#c81215;
}
.subject_nav{
    width:100%;
    padding:0 20px;
    overflow:hidden;
    -webkit-box-sizing: border-box;
    -moz-box-sizing: border-box;
    box-sizing: border-box;
}
.left_tu{
    float:left;
    width:calc(25% - 15px);
    margin-right:20px;
    overflow:hidden;
}
.left_tu img{
    width:100%;
}
.subject_nav .course_list{
    float:left;
    width:calc(75% - 5px);
}
.subject_nav .course_list li{
    float:left;
    width:calc(33.33% - 13.29px);
    background:#fff;
    box-shadow:0 0 5px 1px rgba(0,0,0,0.08);
    margin:0 20px 20px 0;
    overflow:hidden;
    -webkit-box-sizing: border-box;
    -moz-box-sizing: border-box;
    box-sizing: border-box;
}
.subject_nav .course_list li:nth-child(3n){
    margin-right:0;
}
.course_list li .c_down{
    padding:14px;
}
.course_list li .c_down h4{
    width:100%;
    height:60px;
    line-height:30px;
    margin-bottom:5px;
    overflow:hidden;
    display:-webkit-box;
    -webkit-box-orient:vertical;
    text-overflow:ellipsis;
    -webkit-line-clamp:2;
    white-space:inherit;
}
@media screen and (min-width: 1400px){
    .subject_nav .course_list li{
        height:340px;
    }
}   
@media screen and (max-width: 1399px){
    .subject_nav .course_list li{
        height:308px;
    }
    .left_tu img{
        height:636px;
    }
    .subject_nav .course_list li h4{
        height:52px;
        line-height:26px;
    }
    .course_list li .c_down p{
        height:26px;
        line-height:26px;
    }
}  
/*回到顶部 start*/
#return_top{
    position:fixed;
    right:50px;
    bottom:100px;
    width:40px;
    height:40px;
    background:#c91418;
    border-radius:50%;
    text-align: center;
    overflow:hidden;
    display:none;
    cursor: pointer;
}
#return_top i{
    font-size:18px;
    color:#fff;
    line-height:40px;
}
/*回到顶部 end*/
/****************专题学习 end****************/