.body {
    min-width: 1280px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
}

.banner {
    width: 100%;
    height: 26vw;
    min-width: 1280px;
    min-height: 333px;
    background: url('../images/banner4_2025_cn.jpg?20200814a') center 0/100% 100% no-repeat;
}

.main_box {
    width: 100%;
    height: fit-content;
    display: flex;
    flex-direction: column;
    align-items: center;
}

.main_box_content {
    width: 900px;
}

.sub_box {
    width: fit-content;
    height: fit-content;
    margin-bottom: 60px;
}

.sub_box_title {
    font-size: 24px;
    font-family: Source Han Sans CN Medium, Source Han Sans CN Medium-Medium;
    font-weight: 500;
    text-align: left;
    color: #3478dd;
    line-height: 50px;
    margin: 20px 0;
}

.sub_box_title:before {
    content: url('../images/qa_icon_1.png?20200814');
    vertical-align: middle;
    display: inline-block;
    width: 36px;
    height: 36px;
    padding-right: 4px;
}

.sub_box_item {
    width: fit-content;
    height: fit-content;
    margin: 30px 0;
}

.sub_box_item_question {
    font-size: 16px;
    font-family: Source Han Sans CN Regular, Source Han Sans CN Regular-Regular;
    font-weight: 400;
    text-align: left;
    color: #333333;
    margin: 12px 0;
}

.sub_box_item_question:before {
    content: url('../images/qa_icon_2.png?20200814');
    vertical-align: middle;
    display: inline-block;
    width: 20px;
    height: 100%;
    padding-right: 8px;
}

.sub_box_item_answer {
    font-size: 14px;
    font-family: Source Han Sans CN Regular, Source Han Sans CN Regular-Regular;
    font-weight: 400;
    text-align: left;
    color: #000000;
    line-height: 24px;
}

.sub_box_item_answer:before {
    content: 'A:';
    font-size: 14px;
    font-family: Source Han Sans CN Regular, Source Han Sans CN Regular-Regular;
    font-weight: 400;
    text-align: left;
    color: #000000;
    line-height: 24px;
}

.footer {
    width: 100%;
    height: fit-content;
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 50px 0;
    font-size: 18px;
    font-family: Microsoft YaHei Regular, Microsoft YaHei Regular-Regular;
    font-weight: 400;
    text-align: center;
    color: #999999;
    line-height: 33px;
    letter-spacing: 2px;
    background-color: #F8F8F8;
}

.footer a {
}

#dir_tree {
    position: fixed;
    right: 100px;
    top: 100px;
    width: fit-content;
    height: fit-content;
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 20px 0;
}

.dir_tree_bg {
    position: absolute;
    left: 0;
    right: 0;
    top: 0;
    margin: 0 auto;
    width: 6px;
    height: 100%;
    border: 3px solid orange;
    -webkit-box-sizing: border-box;
    -moz-box-sizing: border-box;
    box-sizing: border-box;
    -webkit-border-image: url('../images/qa_right_btn_pole.png') 7 3 stretch;
    -moz-border-image: url('../images/qa_right_btn_pole.png') 7 3 stretch;
    -o-border-image: url('../images/qa_right_btn_pole.png') 7 3 stretch;
    border-image: url('../images/qa_right_btn_pole.png') 7 3 stretch;
}

.dir_tree_content {
    position: relative;
    width: fit-content;
    height: fit-content;
}

.dir_tree_item {
    min-width: 133px;
    width: fit-content;
    height: 43px;
    text-align: center;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 16px;
    margin: 20px 0;
    font-family: Source Han Sans CN Medium, Source Han Sans CN Medium-Medium;
    font-weight: 500;
    background-color: white;
    color: #3478DD;
    line-height: 28px;
    border: solid 2px #3478DD;
    cursor: pointer;
}

.dir_tree_item-selected {
    background-color: #3478DD !important;
    color: #ffffff !important;
    border: none !important;
}