#background_index {
    margin-top: -5%;
    position: relative;
    background: url("/static/image/page.jpg") no-repeat center;
    height: 980px;
    z-index: -1;
}

#product_index {
    margin-top: -10%;
    margin-left: 15%;
}

#left_navigation {
    line-height: 75px;
    width: 170px;
}

.left_choose {
    height: 75px;
    background-color: #E3E3E8;
}

.left_no_choose {
    height: 75px;
    background-color: #F6F7FB;
}

.left_choose div, .left_no_choose div {
    font-size: 23px;
    color: #8A8A8A;
    text-align: center;
    margin-top: 3px;
}

#right_product {
    margin-left: 200px;
    margin-top: -390px;
}

#product_head {
    font-size: 20px;
}

.introduction_index {
    font-size: 18px;
    margin-bottom: 40px;
}

@media screen and (max-width: 1920px) {
    .layui-col-md4 {
        width: 30%;
    }
}

.introduction_index_color {
    color: #939393;
}

.introduction_index a {
    display: block;
    position: relative;
    width: 300px;
    height: 260px;
    overflow: hidden;
}

.introduction_index a span {
    display: block;
    position: absolute;
    left: 0px;
    top: 260px;
    width: 300px;
    height: 200px;
    background-color: #FFF;
    filter: alpha(opacity=90);
    -moz-opacity: 0.9;
    opacity: 0.9;
    text-align: center;
    font-size: 14px;
    color: #666;
}

.introduction_index span p {
    line-height: 40px;
}

.introduction_index span img {
    height: 150px;
    width: 150px;
}

@media screen and (max-width: 1440px) {
    .introduction_index_color{
        font-size: 12px;
    }

    .introduction_index a img{
        width: 75%;
        height: 75%;
    }

    .introduction_index a {
        width: 225px;
        height: 200px;
    }

    .introduction_index a span {
        left: -60px;
        top: 260px;
        height: 150px;
    }

    .introduction_index span p {
        line-height: 40px;
        font-size: 14px;
    }

    .introduction_index span img {
        height: 112px;
        width: 112px;
    }
}

.foot {
    margin-top: 80px;
}