.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 4;
}

.main {
    padding: 107px 0 416px;
    width: 1216px;
    margin: 0 auto;
    overflow: hidden;
    position: relative;
}

.main .navs {
    width: 202px;
    height: 352px;
    background: #f7f7f8;
    border: 1px solid #ececec;
    border-radius: 4px;
    padding: 35px 0 11px;
    position: fixed;
}

.main .navs ul {
    width: 100%;
}

.main .navs li {
    width: 100%;
}

.main .navs li a {
    display: block;
    padding-left: 20px;
    height: 32px;
    line-height: 32px;
    font-size: 14px;
    color: #313131;
    cursor: pointer;
}

.main .navs li.active a {
    background: #EAEAEB;
}

.main .substance {
    width: 710px;
    padding-top: 15px;
    padding-left: 242px;
}

.main .substance .title {
    font-size: 34px;
    color: #313131;
    line-height: 36px;
    margin-bottom: 30px;
    font-weight: 400;
}

.main .substance .second_title {
    font-size: 22px;
    color: #313131;
    line-height: 36px;
    width: 692px;
    padding-bottom: 9px;
    border-bottom: 1px solid rgba(49,49,49,.1);
    font-weight: 400;
    margin-bottom: 30px;
}

.main .substance .android_sdk {
    width: 630px;
    padding: 20px 40px;
    border: 1px solid #E4E4E4;
    border-radius: 4px;
    margin-bottom: 35px;
    overflow: hidden;
}

.main .substance .android_sdk .icon {
    width: 96px;
    height: 96px;
}

.main .substance .android_sdk .text {
    overflow: hidden;
    margin-left: 30px;
}

.main .substance .android_sdk .text p {
    color: #313131;
    font-size: 16px;
    line-height: 24px;
    margin-bottom: 10px;
    margin-top: 10px;
}

.main .substance .android_sdk .desc .col {
    height: 16px;
    line-height: 16px;
    position: relative;
    color: #999999;
    font-size: 14px;
    margin-bottom: 10px;
    padding-left: 20px;
}

.main .substance .android_sdk .desc .col::before {
    content: '';
    width: 4px;
    height: 4px;
    border-radius: 50%;
    background: #999999;
    position: absolute;
    top: 6px;
    left: 0;
}

.main .substance .android_sdk .btn {
    display: block;
    width: 54px;
    height: 32px;
    text-align: center;
    line-height: 32px;
    border: 1px solid #DDDDDD;
    border-radius: 4px;
    color: #313131;
    font-size: 16px;
    margin-top: 32px;
}
.main .substance .android_sdk .ewm {
    width: 72px;
    margin-left: 42px;
    margin-top: 12px;
}

.main .substance .android_sdk .ewm img {
    width: 100%;
}

.main .substance .app_sdk {
    width: 100%;
    overflow: hidden;
    margin-bottom: 35px;
}

.main .substance .app_sdk .row {
    width: 222px;
    height: 284px;
    border: 1px solid #E4E4E4;
    border-radius: 4px; 
    margin-right: 19px;
    padding-top: 20px;
    position: relative;
}

.main .substance .app_sdk .row:last-child {
    margin-right: 0;
}

.main .substance .app_sdk .row .icon {
    width: 79px;
    height: 79px;
    margin: 0 auto 10px;
}

.main .substance .app_sdk .row .icon img {
    width: 100%;
    height: 100%;
    vertical-align: top;
}

.main .substance .app_sdk .row p {
    text-align: center;
    color: #313131;
    font-size: 16px;
    line-height: 24px;
    margin-bottom: 10px;
}

.main .substance .app_sdk .row .desc {
    padding-left: 30px;
}

.main .substance .app_sdk .row .desc .col {
    height: 16px;
    line-height: 16px;
    position: relative;
    color: #999999;
    font-size: 14px;
    margin-bottom: 10px;
    padding-left: 20px;
}

.main .substance .app_sdk .row .desc .col::before {
    content: '';
    width: 4px;
    height: 4px;
    border-radius: 50%;
    background: #999999;
    position: absolute;
    top: 6px;
    left: 0;
}

.main .substance .app_sdk .row .btn {
    display: block;
    width: 54px;
    height: 32px;
    text-align: center;
    line-height: 32px;
    border: 1px solid #DDDDDD;
    border-radius: 4px;
    color: #313131;
    font-size: 16px;
    position: absolute;
    left: 84px;
    bottom: 15px;
}

.main .substance .service_sdk {
    width: 100%;
    overflow: hidden;
    margin-bottom: 11px;
}

.main .substance .service_sdk .row {
    border: 1px solid #E4E4E4;
    border-radius: 4px; 
    width: 344px;
    height: 236px;
    margin-bottom: 22px;
    margin-right: 18px;
    position: relative;
}

.main .substance .service_sdk .row:nth-child(2n) {
    margin-right: 0;
}

.main .substance .service_sdk .row .icon {
    width: 126px;
    margin: 0 auto;
    padding-top: 15px;
}

.main .substance .service_sdk .row p {
    padding-left: 15px;
    color: #313131;
    font-size: 16px;
    line-height: 24px;
    margin-bottom: 10px;
}

.main .substance .service_sdk .row .desc {
    padding-left: 30px;
}

.main .substance .service_sdk .row .desc .col {
    padding-left: 20px;
    height: 16px;
    line-height: 16px;
    position: relative;
    color: #999999;
    font-size: 14px;
    margin-bottom: 10px;
}

.main .substance .service_sdk .row .desc .col::before {
    content: '';
    width: 4px;
    height: 4px;
    border-radius: 50%;
    background: #999999;
    position: absolute;
    top: 6px;
    left: 0;
}

.main .substance .service_sdk .row .btn {
    display: block;
    width: 54px;
    height: 32px;
    text-align: center;
    line-height: 32px;
    border: 1px solid #DDDDDD;
    border-radius: 4px;
    color: #313131;
    font-size: 16px;
    position: absolute;
    left: 14px;
    bottom: 15px;
}

.main .menu {
    width: 230px;
    position: fixed;
    margin-left: 986px;
    top: 107px;
}

.main .menu li {
    padding-left: 6px;
    border-left: 2px solid #FF7D26;
}

.main .menu li a {
    display: block;
    height: 30px;
    line-height: 30px;
    font-size: 14px;
    color: #999999;
}

.main .menu li.active a {
    color: #FF7D26;
}

.main .write {
    width: 710px;
    padding-top: 15px;
    padding-left: 242px;
}

.main .write h1 {
    padding-bottom: .3em;
    font-size: 2.25em;
    line-height: 1.2;
    border-bottom: 1px solid #eee;
}

.main .write p {
    margin: 0.8em 0;
    line-height: 1.6;
}

.main .write h2 {
    padding-bottom: .3em;
    font-size: 1.75em;
    line-height: 1.225;
    border-bottom: 1px solid #eee;
}