/* flex 布局 */
.row-flex {
    display: -webkit-box;
    display: -webkit-flex;
    display: flex;
    -webkit-flex-wrap: wrap;
    flex-wrap: wrap;
    box-sizing: border-box;
}

.row-flex.align-center {
    -webkit-box-align: center;
    -webkit-align-items: center;
    align-items: center;
}

.row-flex.align-bottom {
    -webkit-box-align: end;
    -webkit-align-items: flex-end;
    align-items: flex-end;
}

.row-flex.justify-between {
    -webkit-box-pack: justify;
    -webkit-justify-content: space-between;
    justify-content: space-between;
}

.row-flex.justify-center {
    -webkit-box-pack: center;
    -webkit-justify-content: center;
    justify-content: center;
}

.container {
    width: 1200px;
    margin-left: auto;
    margin-right: auto;
    padding: 40px 0;
}

.title h2 {
    font-size: 32px;
    font-weight: 500;
    color: rgba(51, 51, 51, 1);
}

.title a {
    font-size: 14px;
    font-weight: 400;
    color: rgba(157, 157, 157, 1);
}

.courses .course-item {
    margin-top: 40px;
    margin-right: 44px;
    width: 265px;
    border-radius: 2px;
    border: 1px solid rgba(245, 245, 245, 1);
    transition: all .3s;
}

.courses .course-item:nth-child(4n) {
    margin-right: 0;
}

.courses .course-item .pictrue {
    display: block;
    position: relative;
    width: 100%;
    padding-top: 147px;
    background: rgba(216, 216, 216, 1);
    border-radius: 2px;
    transition: all .3s;
}

.courses .course-item .pictrue img {
    position: absolute;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
}

.courses .course-item .name {
    padding: 0 10px;
    margin-top: 10px;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.courses .course-item .name a {
    font-size: 15px;
    font-weight: 400;
    color: rgba(51, 51, 51, 1);
}

.courses .course-item .info {
    padding: 15px 10px;
}

.courses .course-item .price {
    font-size: 16px;
    font-weight: 500;
}

.courses .course-item .price.free {
    color: rgba(83, 203, 87, 1);
}

.courses .course-item .price.money {
    color: rgba(255, 132, 80, 1);
}

.courses .course-item .learn {
    font-size: 14px;
    font-weight: 400;
    color: rgba(157, 157, 157, 1);
}

.courses .course-item:hover {
    border-radius: 4px;
    transform: translateY(-15px);
}

.courses .course-item:hover .pictrue {
    border-radius: 4px;
    box-shadow: 0 7px 14px 0 rgba(7, 17, 27, 0.1);
}

.courses-list {
    width: calc(50% - 22px);
}

.courses-list .course-item:nth-child(2n) {
    margin-right: 0;
}

.courses-title {
    margin-top: 30px;
    padding-left: 5px;
    border-left: 2px solid rgba(0, 194, 215, 1);
}

.courses-title h3 {
    font-size: 18px;
    font-weight: 400;
    color: rgba(51, 51, 51, 1);
    line-height: 1;
}

.courses-title a {
    font-size: 14px;
    font-weight: 400;
    color: rgba(157, 157, 157, 1);
    line-height: 1;
}

.lecturer-item {
    margin-top: 85px;
    margin-right: 30px;
    width: 217px;
    height: 270px;
    padding: 0 30px 30px;
    background-color: #F3F4F6;
    border-radius: 2px;
    transition: all .3s;
}

.lecturer-item:nth-child(4n) {
    margin-right: 0;
}

.lecturer-item .pictrue {
    display: block;
    margin: -50px auto 0;
    width: 100px;
    height: 0;
    padding-top: 100px;
    border-radius: 50%;
    position: relative;
    transform: translateY(0);
    background-color: #ffffff;
    transition: all .3s;
}

.lecturer-item .pictrue img {
    width: 100%;
    height: 100%;
    position: absolute;
    left: 0;
    top: 0;
    border-radius: 50%;
}

.lecturer-item .name {
    margin-top: 30px;
    text-align: center;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.lecturer-item .name a {
    font-size: 15px;
    font-weight: 400;
    color: rgba(51, 51, 51, 1);
}

.lecturer-item .info {
    margin-top: 10px;
    text-align: center;
    font-size: 14px;
    font-weight: 400;
    color: rgba(157, 157, 157, 1);
}

.lecturer-item .desc, .lecturer-item .desc p {
    font-size: 14px;
    font-weight: 400;
    color: #444444;
    line-height: 1.8;
    overflow: hidden;
    -webkit-line-clamp: 4;
    line-clamp: 4;
    -webkit-box-orient: vertical;
    box-orient: vertical;
    display: -webkit-box;
    display: box;
}

.lecturer-item .desc {
    margin-top: 20px;
    height: 100px;
}

.lecturer-item:hover {
    border-radius: 4px;
    transform: translateY(-5px);
    box-shadow: 0 5px 8px 0 rgba(7, 17, 27, 0.1);
}

.lecturer-item:hover .pictrue {
    box-shadow: 0 0 14px 0 rgba(7, 17, 27, 0.1);
    transform: scale(1.06);
}

.lecturer-item .more {
    text-align: center;
    margin-top: 15px;
}

.lecturer-item .more a {
    display: inline-block;
    font-size: 12px;
    font-weight: 400;
    color: rgba(0, 194, 215, 1);
    border-radius: 15px;
    border: 1px solid rgba(0, 194, 215, 1);
    padding: 2px 10px;
}