.jiaoshi{}
.jiaoshi ul {
    display: flex;
    flex-wrap: wrap;}
.jiaoshi ul li {
    width: 48%;
    margin: 1%;
    padding: 1%;
    box-shadow: 0 0 9px #c2c2c2;}
.jiaoshi ul li a{
    display: flex;
    flex-wrap: wrap;}
.jiaoshi ul li .cover_img{
    width: 160px;
    height: 200px;}
.jiaoshi ul li .txt{
    width: calc(100% - 180px);
    margin-left: 20px;}
.jiaoshi ul li h3{
    font-size: 20px;
    margin-bottom:15px;
    line-height: 42px;
    display: -webkit-box;
    -webkit-box-orient: vertical;
    -webkit-line-clamp: 1;
    overflow: hidden;}
.jiaoshi ul li p {
    line-height: 36px;
    font-size: 16px;
    color: #666;}
.jiaoshi ul li:hover h3 {
    font-weight: bold;}
@media only screen and (max-width: 680px){
.jiaoshi ul li {
    width: 98%;
    margin: 10px 1%;}
}
@media only screen and (max-width: 420px){
.jiaoshi ul li .cover_img {
    width: 120px;
    height: 160px;}
.jiaoshi ul li .txt {
    width: calc(100% - 130px);
    margin-left: 10px;}
}