.courses_details {
    background: #F4F4F4;
}

@media screen and (max-width: 767px) {
    .courses_details_main_box {
        /* padding-top: 8rem; */
        width: 100vw !important;
    }

    .courses_details_top {
        height: 40rem;
        padding-top: 20rem;
    }

    .courses_details_top_mian_title {
        font-size: 6rem;
        margin-bottom: 2rem;
    }

    .courses_details_top_mian_info {
        font-size: 4rem;
    }

    .courses_details_main_content_box {
        /* width: calc(100vw - 3.2rem); */
        /* width: 100vw !important; */
        width: 100%;
        margin: 0 auto;
        background: #fff;
        float: right;
        padding: 8rem 4rem;
        box-sizing: border-box;
        font-size: 6rem;
    }

    .courses_main_bottom_btn_item {
        background: #F4F4F4;
        height: 40rem;
        border-radius: 5rem;
        padding: 6rem;
        margin-top: 6rem;
    }

    .courses_main_bottom_btn_item .item_btn_box {
        width: calc(100% - 12rem);
        bottom: 3rem;
        height: 10rem;
    }

    .item_btn_box i {
        font-size: 6rem;
    }

    .courses_related_articles {
        margin-top: 6rem;
    }

    .courses_related_articles_title {
        font-size: 8rem;
    }

    .courses_related_articles_list {
        background-color: #F4F4F4;
        margin-top: 6rem;
        border-radius: 5rem;
        padding: 6rem;
        gap: 6rem;
        font-size: 6rem;
    }

    .courses_related_articles_item {
        width: 100%;
        white-space: nowrap;
        text-overflow: ellipsis;
        overflow: hidden;
        color: #333;
    }
}

@media screen and (min-width: 768px) {
    .courses_details_main_box {
        padding-top: 4rem;
    }

    .courses_details_top {
        height: 30rem;
        padding-top: 10rem;
    }

    .courses_details_top_mian_title {
        font-size: 4rem;
        margin-bottom: 1.2rem;
    }

    .courses_details_top_mian_info {
        font-size: 2rem;
    }

    .courses_details_main_content_box {
        width: 75rem;
        margin: 0 auto;
        padding: 3rem 0rem;
    }

    .courses_main_bottom_btn_item {
        background-color: #fff;
        height: 18rem;
        border-radius: 2rem;
        padding: 3rem;
        margin-top: 2rem;
    }

    .courses_main_bottom_btn_item .item_btn_box {
        width: calc(100% - 6rem);
        bottom: 3rem;
        height: 5rem;
    }

    .item_btn_box i {
        font-size: 2rem;
    }

    .courses_related_articles_item {
        width: calc(50% - 1rem);
        cursor: pointer;
        white-space: nowrap;
        text-overflow: ellipsis;
        overflow: hidden;
        color: #333;
        font-weight: bold;
    }

    .courses_related_articles {
        margin-top: 4rem;
    }

    .courses_related_articles_title {
        font-size: 3rem;
    }

    .courses_related_articles_list {
        background-color: #fff;
        margin-top: 1rem;
        border-radius: 1rem;
        padding: 2rem;
        gap: 2rem;
    }
}

.courses_details_main_box {
    overflow: hidden;
    position: relative;
}

/* 顶部信息 */
.courses_details_top {
    color: #fff;
    position: relative;
}

.courses_details_top::before {
    content: '';
    position: absolute;
    top: 30%;
    left: 0;
    width: 100%;
    height: 70%;
    background: linear-gradient(to bottom, rgba(255, 255, 255, 0), #f6faff);
}

.courses_details_top_mian_title {
    font-weight: bold;
    text-align: center;
}

.courses_details_top_mian_info {
    display: flex;
    justify-content: center;
}

.courses_details_top_mian_info span {
    display: inline-block;
    padding: 0 1.4rem;
    position: relative;
}

.courses_details_top_mian_info span::after {
    content: '';
    display: block;
    position: absolute;
    right: 0;
    top: 50%;
    transform: translate(-50%, -50%);
    height: 1.5rem;
    width: 0;
    border-right: 1px solid #fff;
    opacity: .59;
}



/* 导航 */
.courses_details_main_content_nav {
    width: 26rem;
    background: #fafafa;
    position: absolute;
    border-radius: 1.4rem;
    padding: 3rem 1.5rem;
    box-sizing: border-box;
    top: 4rem;
}

.courses_details_nav_list {
    display: flex;
    flex-direction: column;
}

.courses_details_nav_item {
    display: flex;
    align-items: center;
    height: 5rem;
    line-height: 5rem;
    margin-bottom: 1.2rem;
    padding: 0 2rem;
    cursor: pointer;
    color: #8a8a8a;
    border-radius: 0.8rem;
    -webkit-border-radius: 0.8rem;
    -moz-border-radius: 0.8rem;
    -ms-border-radius: 0.8rem;
    -o-border-radius: 0.8rem;
}

.courses_details_nav_item:hover,
.courses_details_nav_item_active {
    background-color: #ffefe5;
    color: #ff6000;
}

.courses_details_nav_item i {
    font-size: 2rem;
    /* margin-right: 1.6rem; */
}

.courses_details_nav_item span {
    margin-left: 1rem;
}

/* 课程内容 */
.courses_details_main_content_box img,
.courses_details_main_content_box video {
    max-width: 100%;
    height: auto;
    /* margin: 1rem 0; */
}

/* 底部按钮以及【相关文章】 */
.courses_details_main_bottom_box {}

.courses_main_bottom_btn {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: center;
    gap: 3.2rem;


}

.courses_main_bottom_btn_item {

    flex: 1;
    box-sizing: border-box;
    position: relative;
    cursor: pointer;

}

.courses_main_bottom_btn_item>p {
    font-weight: bold;
    color: #333333;
    display: -webkit-box;
    -webkit-box-orient: vertical;
    /* 表示盒子对象的子元素的排列方式 */
    -webkit-line-clamp: 2;
    /* 限制文本的行数，表示文本第多少行省略 */
    text-overflow: ellipsis;
    /*  打点展示 */
    overflow: hidden;
    /*超出部分进行隐藏*/
}

.courses_main_bottom_btn_item .item_btn_box {
    position: absolute;
    background-color: #ff6000;
    color: #fff;
    display: flex;
    justify-content: center;
    align-items: center;
    cursor: pointer;
}




.courses_related_articles_item:hover {
    color: #ff6000;
}

.courses_related_articles_title {

    color: #333333;
    font-weight: bolder;
}

.courses_related_articles_list {
    display: flex;
    flex-wrap: wrap;



}