.about-us-box{background-color: #fff;}
.section1-box{max-width: 1200px;padding: 0 30px;margin: 0 auto;}
.section1-content{max-width: 796px;margin: 120px auto;}
.section1-content .section1-img{padding-top: 98.6%;box-sizing: border-box;background-repeat: no-repeat;background-size: cover;background-position: 50%;}

.section2-box{background-color: #FBFBFB;}
.section2-content{max-width: 1200px;padding: 60px 30px;margin: 0 auto;}
.section2-content>h2{color: #1B1B1B;font-size: 30px;text-align: center;margin-bottom: 15px;line-height: 42px;}
.section2-content>p{color: #646464;font-size: 16px;line-height: 32px;}

.section3-box{max-width: 1200px;margin: 0 auto;padding: 0 30px;}
.section3-box>li{display: flex;align-items: center;justify-content: space-between;margin-top: 100px;}
.section3-box>li .item-pic{max-width: 289px;flex: 1;}
.section3-box>li .item-pic .i-img{padding-top: 126.8%;background-repeat: no-repeat;background-size: cover;background-position: 50%;}
.section3-box>li.item-right .item-pic .i-img{padding-top: 122.8%;}
.section3-box>li .item-info>h2{color: #1B1B1B;font-size: 30px}
.section3-box>li .item-info>p{color: #646464;font-size: 16px;line-height: 32px;margin-top: 16px;}
.section3-box>li.item-right .item-pic{order: 2;}
.section3-box>li.item-right .item-info{order: 1;}
.section3-box>li.item-left .item-pic{order: 1;}
.section3-box>li.item-left .item-info{order: 2;}
.section3-box>li.item-left .item-info{width: 515px;flex: none;background: url(/images/service/bg1.png) no-repeat bottom right;padding: 76px 0 20px;text-align: right;background-size: contain;}
.section3-box>li.item-right .item-info{width: 527px;flex: none;background: url(/images/service/bg2.png) no-repeat bottom left;padding-bottom:36px;text-align: left;background-size: contain;}

.section4-box{max-width: 408px;width: 100%;margin: 132px auto 58px;}
.section4-box>a{display: block;background-color: #1B1B1B;border-radius: 10px;text-align: center;width: 100%;line-height: 60px;color: #fff;font-size: 16px;cursor: pointer;}
.section4-box>a:hover{background-color: #313131;}

@media screen and (max-width:1920px) {
    .section1-box{max-width: 1048px;}
    .section2-content{max-width: 1048px;}
    .section2-content>p{font-size: 14px;}
    .section3-box{max-width: 1048px;}
    .section3-box>li .item-info>p{font-size: 14px;}
}

@media screen and (max-width:1048px) {
    .section3-box>li.item-left .item-info{width: 415px;}
    .section3-box>li.item-right .item-info{width: 427px;}
}

@media screen and (max-width:800px) {
    .section3-box>li.item-left .item-info{width: 315px;}
    .section3-box>li.item-right .item-info{width: 327px;}
}