.preview {
    position: relative;
}

.preview .bg-img {
    position: absolute;
    width: 100%;
    height: 400px;
    left: 0;
    bottom: 80px;
    background: url("../images/preview-bg.png") no-repeat 100% 100%/ 100% 100%;
}

.three .swiper {
    margin-top: 40px;
    overflow: hidden;
    width: 100%;
    position: relative;
}

.preview .swiper-slide {
    text-align: center;
}

.preview1 .preview-view .view-img {
    padding-bottom: 380px;
}

.three .three-preview .view-img {
    margin-bottom: 60px;
}


.preview .preview-view .view-img .img-inner {
    width: 1200px;
    height: auto;
    object-fit: contain;
}

.preview .preview-info {
    text-align: center;
    width: 730px;
    margin: 38px auto 0;
}

.preview .preview-info .preview-name {
    margin-bottom: 10px;
    color: #333;

    font-size: 20px;
    line-height: 28px;
}

.preview .preview-info .preview-content {
    color: #666;
    font-size: 14px;
    line-height: 20px;
    text-align: left;
    text-indent: 2em;
}

.use-area {
    position: relative;
}

.use-area .area-list {
    font-size: 0;
    display: flex;
    align-items: center;
    flex-wrap: wrap;
    margin-top: 30px;
}

.use-area .area-list .area-option {
    width: 280px;
    height: 315px;
    position: relative;
    margin-right: 26px;
    margin-bottom: 28px;
    display: inline-block;
    border-radius: 10px;
    overflow: hidden;
}

.use-area .area-list .area-option:nth-child(4n) {
    margin-right: 0;
}

.use-area .area-list .area-option .area-img {
    width: 100%;
    height: 100%;
    position: absolute;
    left: 0;
    top: 0;
    z-index: 2;
}

.use-area .area-list .area-option .area-info {
    width: 100%;
    height: 100%;
    position: relative;
    z-index: 3;
    box-sizing: border-box;
    padding: 200px 15px 0;
    background: linear-gradient(180deg, rgba(8, 22, 36, 0.5) 0%, #1E2733 100%);
}

.product .use-area .area-list .area-option .area-info:hover,
.product .use-area .area-list .area-option .area-info:active {
    padding: 1.5rem 1.5rem 0;
}

.use-area .area-list .area-option .area-info .area-name {

    font-size: 20px;
    line-height: 24px;
    color: #fff;
    margin-bottom: 5px;
}

.use-area .area-list .area-option .area-info .area-desc {
    font-size: 12px;
    line-height: 16px;
    color: rgba(255, 255, 255, 0.77);
}

.typical-cases {
    padding: 75px 0 50px;
    background-size: auto;
    position: relative;
}


.typical-cases .bg-img {
    position: absolute;
    width: 143px;
    height: 195px;
    right: 0;
    bottom: 30%;
    background-size: cover;
    background-image: url("../images/three-item-bg-3.png");
}

.typical-cases .list {
    margin-top: 70px;
}

.typical-cases .list li {
    width: 45%;
    border-radius: 10px;
    position: relative;
    display: inline-block;
    vertical-align: text-top;
    margin: 0 1.5% 20px;
    background: #fff;
    box-shadow: 2px 2px 25.1px 0 #00000014;
}

.typical-cases .list .icon {
    width: 100px;
}

.typical-cases .list .title {
    font-size: 24px;
    color: #333333;
    font-weight: bold;
    margin-top: 50px;
}


.typical-cases .list .item .desc {
    color: #333333;
    font-size: 16px;
    font-style: normal;
    line-height: normal;
    padding: 20px 35px;
    flex-shrink: 0;
    background: #F8F8F8;
}


.typical-cases .list .item .desc:hover {
    color: #FFFFFF;
    background: linear-gradient(90deg, #3D7AFC 0%, #F9F9F9 108.9%);
}

@media screen and (min-width: 320px) and (max-width: 767px) {
    .product .use-area .area-list .area-option {
        width: calc((100% - 20px)/2);
        height: 250px;
        margin-right: 20px;
    }

    .product .use-area .area-list .area-option:nth-child(2n) {
        margin-right: 0;
    }

    .three .three-preview .view-img {
        margin-bottom: 0px;
    }
}

/* 
    .preview {
        margin-bottom: 2rem;
    }

    .preview .preview-info {
        text-align: center;
        margin: 1rem auto 0;
        width: 80%;
    }

    .preview .preview-info .preview-name {
        margin-bottom: 1rem;
        color: #333;

        font-size: 1.2rem;
        line-height: 2rem;
    }

    .preview .preview-info .preview-content {
        font-size: 0.8rem;
        line-height: 1.5rem;
    }

    .advantage {
        position: relative;
        height: auto;
    }

    .advantage .idx_titbox {
        padding-left: 0;
    }

    .advantage .advantage-list {
        padding-top: 1rem;
        font-size: 0;
        line-height: 0;
        flex-wrap: wrap;
        margin-left: 10px;
        justify-content: space-evenly;
    }

    .advantage .advantage-list .advantage-option {
        display: inline-block;
        width: 10rem;
        height: 10rem;
        margin-right: 0rem;
        margin-bottom: 1rem;
        box-sizing: border-box;
        padding: 1rem 0.5rem 0;
        border: 0.1rem solid #fff;
        color: #fff;
        border-radius: 1rem;
    }

    .advantage .advantage-list .advantage-option .option-title {
        font-size: 1rem;
        line-height: 1rem;
        margin-bottom: 0.5rem;
    }

    .advantage .advantage-list .advantage-option .option-content {
        font-size: 0.6rem;
        line-height: 0.8rem;
        color: rgba(255, 255, 255, 0.8);
    }

    .advantage .advantage-list .advantage-option:nth-child(3n) {
        margin-right: 0;
        margin-bottom: 1rem;
    }

    .advantage .advantage-list .advantage-option:hover {
        background-color: #fff;
        color: #3d7afc;
    }

    .advantage .advantage-list .advantage-option:hover .option-content {
        color: rgba(61, 122, 252, 0.8);
    }

    .advantage .advantage-list .advantage-option:nth-child(7n) {
        position: relative;
        left: -90px;
        margin-bottom: 30px;
    }


    .advantage .advantage-img {
        width: 35rem;
        margin: 0 auto;
    }

    .use-area .area-list {
        font-size: 0;
        justify-content: center;
    }

    .use-area .area-list .area-option {
        width: 10rem;
        height: 14.5rem;
        position: relative;
        margin-right: 0.5rem;
        margin-bottom: 1rem;
        display: inline-block;
        box-sizing: border-box;
        overflow: hidden;
        border-radius: 0.5rem;
    }

    .use-area .area-list .area-option:nth-child(2n) {
        margin-right: 0;
    }

    .use-area .area-list .area-option .area-img {
        width: 100%;
        height: 100%;
        position: absolute;
        left: 0;
        top: 0;
        z-index: 2;
    }

    .use-area .area-list .area-option .area-info {
        width: 100%;
        height: 100%;
        position: relative;
        z-index: 3;
        box-sizing: border-box;
        padding: 12.5rem 1.5rem 0;
        background: linear-gradient(180deg, rgba(8, 22, 36, 0) 0%, #1E2733 100%);
    }

    .use-area .area-list .area-option .area-info .area-name {

        font-size: 1rem;
        line-height: 1.2rem;
        color: #fff;
        margin-bottom: 1rem;
    }

    .use-area .area-list .area-option .area-info .area-desc {
        font-size: 0.6rem;
        line-height: 1rem;
        color: rgba(255, 255, 255, 0.77);
    }

    .preview .preview-view .view-img .img-inner {
        width: 90%;

    }

    .advantage .advantage-img {
        display: none;
    }

    .typical-cases .list {
        margin-top: 30px;
    }

    .typical-cases .list li {
        width: 100%;
        margin: 10px 0;
    }

    .typical-cases .list .item .desc {
        padding: 15px;
    }
} */