.banner_box {
    width: 100%;
    height: calc(60px + 25rem);
    background: url(../images/zhgc.jpg) no-repeat;
    background-size: cover;
    position: relative;
}

.banner {
    max-width: 1420px;
    width: 85%;
    height: 100%;
    margin: auto;
    display: flex;
    flex-direction: column;
    justify-content: center;

}

.banner_nav_box {
    width: 100%;
    border-bottom: 1px #ffffff48 solid;
    position: absolute;
    top: 0;
    height: calc(10px + 2rem);
    display: flex;
    flex-direction: column;
    justify-content: center;

}

.banner_nav {
    max-width: 1420px;
    width: 85%;
    margin: auto;
    display: flex;
    justify-content: flex-start;
    align-items: center;
    gap: 0.5rem;
}

.banner_nav div {

    font-family: PINGFANG;
    font-weight: 300;
    font-size: calc(6px + 0.5rem);
    color: #FFFFFF;

}

.banner_text {
    display: flex;
    flex-direction: column;
    justify-content: flex-start;
    align-items: flex-start;
    gap: calc(1px + 0.5rem);
}

.banner_text div:nth-of-type(1) {

    font-family: PINGFANG;
    font-weight: 400;
    font-size: calc(10px + 1.5rem);
    color: #FEFEFE;
}

.banner_text div:nth-of-type(2) {

    font-family: PINGFANG;
    font-weight: 400;
    font-size: calc(10px + 1rem);
    color: #FEFEFE;
}

.nav_box {
    width: 100%;

    height: calc(20px + 3rem);
    background: #FFFFFF;
    box-shadow: 0px 4px 6px 0px rgba(3, 15, 53, 0.05);
    display: flex;
    flex-direction: column;
    align-items: center;
}

.nav {
    max-width: 1420px;
    width: 85%;
    height: 100%;
    margin: auto;
    display: flex;
    justify-content: center;
    align-items: center;
    gap: calc(9px + 30rem);
}

.nav .navItem {
    height: 100%;
    font-family: PINGFANG;
    font-weight: 400;
    font-size: calc(10px + 0.5rem);
    color: #333333;
    display: flex;
    align-items: center;
}
.nav .navItem:hover{
    color: #D21010;
}
.nav a{
    position: relative;
}
.nav a:hover .nav_line{
    width: 100%;
    transition: .5s;
}
.nav_line{
    width: 0;
    height: 1px;
    background-color: #D21010;
    position: absolute;
    bottom: 0;
    left: 0;
}

.nav a {
    height: 100%;
}

.nav a:nth-of-type(1) .navItem {
    color: #D21010;
    border-bottom: 1px #D21010 solid;

}


.ai_research_box {
    width: 100%;
    margin-top: calc(30px + 5rem);
    margin-bottom: calc(30px + 5rem);
}

.ai_research {
    max-width: 1420px;
    width: 85%;

    margin: auto;
    display: flex;
    justify-content: space-between;
    background: #F8F9FA;
}

.ar_research_pic {
    width: calc(40px + 15rem);
    height: calc(55px + 20rem);
    position: relative;
}

.ar_research_pic img {
    width: 100%;
    height: 100%;
}

.ai_research_text {
    flex: 1;
    display: flex;
    flex-direction: column;
    justify-content: center;
    gap: calc(4px + 0.5rem);
    padding: 0 calc(33px + 5rem);
}

.ai_research_text p:nth-of-type(1) {

    font-family: PINGFANG;
    font-weight: 400;
    font-size: calc(2px + 1rem);
    color: #D21010;
}

.ai_research_text p:nth-of-type(2) {
    font-family: PINGFANG;
    font-weight: 600;
    font-size: calc(10px + 1rem);
    color: #333333;
}

.ai_research_text p:nth-of-type(3) {
    font-family: PINGFANG;
    font-weight: 300;
    font-size: calc(6px + 0.5rem);
    color: #4D4D4D;
    line-height: calc(2px + 1.5rem);
    margin-top: calc(7px + 1rem);
    text-align: justify;
}

.ai_research_text p:nth-of-type(4) {
    font-family: PINGFANG;
    font-weight: 300;
    font-size: calc(6px + 0.5rem);
    color: #4D4D4D;
    line-height: calc(2px + 1.5rem);
    text-align: justify;
}
.ai_research_text p:nth-of-type(5) {
    font-family: PINGFANG;
    font-weight: 300;
    font-size: calc(6px + 0.5rem);
    color: #4D4D4D;
    line-height: calc(2px + 1.5rem);
    text-align: justify;
}
.ai_research_text p:nth-of-type(6) {
    font-family: PINGFANG;
    font-weight: 300;
    font-size: calc(6px + 0.5rem);
    color: #4D4D4D;
    line-height: calc(2px + 1.5rem);
    text-align: justify;
}
.line {
    max-width: 1420px;
    width: 85%;
    margin: auto;
    height: 2px;
    background: #EEEEEE;
    margin-bottom: calc(30px + 5rem);
}

.card_group_box {
    width: 100%;

    margin-bottom: calc(26px + 10rem);
}

.card_group {
    max-width: 1420px;
    width: 85%;
    margin: auto;

}

.card_group_title {

    font-family: PINGFANG;
    font-weight: 600;
    font-size: calc(10px + 1rem);
    color: #333333;
    text-align: center;

}

.card_group_bg {
    width: 100%;
    height: calc(150px + 20rem);
    background: url(../images/cardbg.png) no-repeat;
    background-size: cover;
}

.card_group_pic {
    width: 100%;
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: calc(9px + 3rem);

}

.card_group_item {
    width: 19%;
    height: calc(150px + 20rem);
    background: #ffffff41;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    cursor: pointer;
    border: 1px #ffffff46 solid;
}

.card_group_item:nth-of-type(1) {
    width: 43%;
    background-color: transparent;

}

.card_num {

    font-family: PINGFANG;
    font-weight: bold;
    font-size: calc(10px + 1rem);
    color: #FEFEFE;
    padding-left: 10%;
    padding-top: calc(2px + 3rem);
}
.card_group_item:nth-of-type(1) .card_text{
   opacity: 1;
}
.card_text {
    height: calc(45px + 5rem);
    margin-bottom: calc(2px + 2rem);
   opacity: 0;
   width: calc(57px + 28rem);
}

.card_text p:nth-of-type(1) {

    font-family: PINGFANG;
    font-weight: 400;
    font-size: calc(10px + 1rem);
    color: #FEFEFE;
    padding: 0 calc(3px + 3rem);
}

.card_text p:nth-of-type(2) {

    font-family: PINGFANG;
    font-weight: 400;
    font-size: calc(6px + 0.5rem);
    color: #FEFEFE;
    opacity: 0.96;
    padding: 0 calc(3px + 3rem);
    line-height: calc(2px + 1.5rem);
    margin-top: calc(10px + 0.5rem);
    text-align: justify;
}
.card_text p:nth-of-type(3) {

    font-family: PINGFANG;
    font-weight: 400;
    font-size: calc(6px + 0.5rem);
    color: #FEFEFE;
    opacity: 0.96;
    padding: 0 calc(3px + 3rem);
    line-height: calc(2px + 1.5rem);
    margin-top: calc(10px + 0.5rem);
    text-align: justify;
}
.know_more{
    width: calc(33px + 5rem);
    line-height: calc(6px + 1.5rem);
    border-radius: calc(10px + 1rem);
    text-align: center;
    position: absolute;
    bottom: 6%;
    left: 50%;
    transform: translate(-50%);
    opacity: 0;
}

@media (max-width: 1100px) {
    .banner_nav_box{
        display: none;
    }
   
    .ai_research{
        display: flex;
        flex-direction: column;
        justify-content: flex-start;
    }
    .ai_research_text{
        width: 100%;
        padding: 15px;
    }
    .ai_research_text p:nth-of-type(1){
        font-size: calc(10px + 1rem);
    }
    .ai_research_text p:nth-of-type(3){
        font-size: calc(10px + 1rem);
        line-height: 20px;
    }
    .ai_research_text p:nth-of-type(4){
        font-size: calc(10px + 1rem);
        line-height: 20px;
    }
    .ar_research_pic{
        width: 100%;
        height: auto;
    }
    .card_group_item{
        display: flex;
        flex-direction: column;
        justify-content: flex-start;
        gap: calc(5px + 0.5rem);
    }
    .card_text{
        width: 100%;
    }
    .card_text p{
        padding: 0 ;
    }
    .card_text p:nth-of-type(2){
       padding-bottom: 20%;
        overflow: hidden;
        font-size: calc(8px + 1rem);
        line-height: calc(8px + 3rem);
        height: 182%;
    }
    .ai_research_box{
        margin-top: 0;
    }
    .ai_research_text p:nth-of-type(2){
        font-size: calc(16px + 1rem);
    }
}