.ban_box{
    width: 100%;
    position: relative;

}
.ban_box img{
    width: 100%;
}
.meng{
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: #000;
    opacity: 0.3;
}
.ab_us{
    position: absolute;
    bottom: 130px;
    left: 100px;
    font-size: 46px;
    font-weight: 600;
    color: #fff;
}
.mission{
    width: 100%;
    height: 400px;
    background-color: #012DA7;
    display: flex;
    justify-content: space-between;
    margin-top: 100px;
    margin-bottom: 100px;
    align-items: center;
}
.mi_le{
    width: 35%;
    display: flex;
    flex-direction: column;
    gap: 20px;
    color: #fff;
    padding: 50px;
    box-sizing: border-box;
    
}
.mi_le :nth-child(1){
    font-size: 36px;
    font-weight: 600;
    text-align: center;
}
.mi_le :nth-child(2){
    line-height: 30px;
}
.mission img{
    width: 50%;
    height: 500px;
    margin-right: 100px;
}
.time_xian{
    width: 100%;
}
.time_con{
    margin: 50px auto;
}
.time_con img{
    width: 100%;
    margin: 50px auto;
}
.b3_box{
    padding: 30px 100px;
    box-sizing: border-box;
    width: 100%;
    display: flex;
    justify-content: space-between;
    align-items: center;
    background-color: #012DA7;
    margin-top: 50px;
    margin-bottom: 50px;
}
.b3_list{
    display: flex;
    flex-direction: column;
    gap: 20px;
    width: 31%;
    color: #fff;
    align-items: center;
}
.b3_list img{
    width: 50px;
    height: 50px;
}
.b3_list :nth-child(1){
    font-size: 24px;
    font-weight: 600;
}
.b3_list :nth-child(3){
    font-size: 40px;
    font-weight: 600;
}
.b4_box{
    display: flex;
    flex-direction: column;
    gap: 20px;
    margin-bottom: 50px;
    padding: 0 100px;
    box-sizing: border-box;
}
.b4_list{
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 400px;
}
.b4_list img{
    width: 60%;
    height: 100%;
}
.b4_wen{
    width: 35%;
    display: flex;
    flex-direction: column;
    gap: 20px;
    background-color: #012DA7;
    height: 100%;
    align-items: center;
    justify-content: center;
    padding: 30px;
    box-sizing: border-box;
}
.b4_wen :nth-child(1){
    font-size: 26px;
    font-weight: 600;
    color: #fff;
}
.b4_wen :nth-child(2){
    line-height: 30px;
    color: #fff;
}

.timeline-xian {
    width: 100%;
    max-width: 1100px;
    margin: 60px auto 80px auto;
    position: relative;
    background: #f8f8f8;
}
.timeline-xian::before {
    content: '';
    position: absolute;
    left: 50%;
    top: 0;
    width: 6px;
    height: 100%;
    background: #2563eb;
    transform: translateX(-50%);
    z-index: 0;
}
.timeline-row {
    display: flex;
    width: 100%;
    min-height: 60px;
    position: relative;
}
.timeline-col {
    width: 50%;
    display: flex;
    flex-direction: column;
    align-items: flex-end;
    justify-content: center;
    position: relative;
    min-height: 60px;
    padding: 20px 0;
}
.timeline-col.right {
    align-items: flex-start;
    padding-left: 60px;
}
.timeline-col.left {
    align-items: flex-end;
    padding-right: 60px;
}
.timeline-year {
    font-size: 40px;
    font-weight: 700;
    color: #111;
    background: #fff;
    z-index: 2;
    margin-bottom: 0;
}
.timeline-dot {
    width: 32px;
    height: 32px;
    background: #2563eb;
    border-radius: 50%;
    border: 4px solid #ffffff;
    margin: 0 0 0 12px;
    z-index: 2;
    position: relative;
    top: -8px;
}
.timeline-col.right .timeline-dot {
    margin: 0 0 0 -12px;
}
.timeline-title {
    font-size: 20px;
    font-weight: 400;
    margin-bottom: 0;
    margin-top: 8px;
    background-color: #f8f8f8;
    font-weight: 600;
}
.timeline-desc {
    font-size: 18px;
    color: #222;
    margin-top: 10px;
    margin-bottom: 0;
    line-height: 1.3;
    text-align: center;
    max-width: 400px;
    background-color: #f8f8f8;
    font-weight: 600;
}
.timeline-img {
    width: 320px;
    height: 180px;
    object-fit: cover;
    border-radius: 0px;
    margin-bottom: 10px;
    margin-top: 10px;
    box-shadow: 0 0 0 1px #aaa;
}
@media (max-width: 900px) {
    
}

@media (max-width: 768px){
    .timeline-xian { max-width: 100%; }
    .timeline-row { flex-direction: column; }
    .timeline-col, .timeline-col.left, .timeline-col.right {
        width: 100%;
        align-items: center;
        padding: 0;
    }
    .timeline-img { width: 90vw; max-width: 320px; }
    .ab_us{
        left: 30px !important;
        bottom: 30px !important;
        font-size: 20px !important;

    }
    .mission{
        flex-direction: column !important;
    }
    .mi_le{
        padding: 10px !important;
        width: 100% !important;
    }
    .mission img{
        width: 100% !important;
        margin-right: 0 !important;
    }
    .b3_box{
        padding: 10px !important;
        flex-direction: column !important;
        gap: 30px;
    }
    .b3_list{
        width: 100% !important;
    }
    .b4_box{
        flex-direction: column !important;
        padding: 10px !important;
        gap: 115px;
    }
    .b4_list{
        flex-direction: column !important;
    }
    .b4_list img,.b4_wen{
        width: 100% !important;
    }
}