* {
    font-family: SourceHanSansCN, sans-serif;
}

/*公共头部导航---结束---*/
body {
    padding-top: 75px;
}

header {
    width: 100%;
    background: #fff;
    height: 75px;
    line-height: 75px;
    box-shadow: 0px 2px 12px 0px rgba(0,0,0,0.07);
    position: fixed;
    top: 0;
    z-index: 999;
}

header .main {
    width: 1200px;
    margin: 0 auto;
}

header .main .left {
    float: left;
}

header .main .left img {
    height: 36px;
}

header .main .right {
    float: right;
}

header .main .right a {
    font-size: 16px;
    color: #000;
    font-weight: 400;
    margin-right: 120px;
}

header .main .right a:hover {
    color: #2050D1;
    font-weight: 500;
}

header .main .right a:last-child {
    margin-right: 0;
}

header .main .right a.active {
    color: #2050D1;
    font-weight: 500;
}
/*公共头部导航---结束---*/

.banner {
    width: 100%;
    min-width: 1200px;
    height: 400px;
    background: url(https://www.f139content.com/website/sci99/images/about/banner.png) top center no-repeat;
}

.banner .slogan-box {
    width: 1200px;
    margin: 0 auto;
    padding-top: 120px;
    color: #fff;
}

.banner .slogan-box .title {
    font-weight: bold;
    font-size: 60px;
    text-align: justify;
    margin-bottom: 13px;
}

.banner .slogan-box .description {
    font-weight: 500;
    font-size: 38px;
    text-align: justify;
}

.div_main {
    background: #fff;
    width: 1200px;
    min-height: 500px;
    margin: 0 auto;
    padding: 70px 0 80px 0;
}

.clearfix:after {
    visibility: hidden;
    display: block;
    font-size: 0;
    content: " ";
    clear: both;
    height: 0;
}

h2 {
    position: relative;
}

h2 span {
    font: 700 38px / 50px "SourceHanSansCN, sans-serif";
    color: #000;
    position: relative;
    z-index: 99;
}

h2 i {
    font: 600 50px / 60px arial;
    color: #F2F2F2;
    position: absolute;
    left: 0;
    top: -20px;
    z-index: 88;
}

.div_main section {
    margin-bottom: 80px;
}

.div_main section:last-child {
    margin-bottom: 0;
}

.div_main .left, .div_main .right {
    width: 600px;
    float: left;
}

.div_main .text-box {
    margin-top: 25px;
}

.div_main .text-box p {
    font-weight: 400;
    font-size: 16px;
    color: #666666;
    line-height: 26px;
    text-align: justify;
    font-style: normal;
    margin-bottom: 30px;
}

.div_main .text-box p:last-child {
    margin-bottom: 0;
}

.video-container {
    margin-top: 25px;
    position: relative;
    width: 600px;
    height: 330px;
    border-radius: 8px;
    overflow: hidden;
}

video {
    width: 100%;
    display: block;
    background: #000;
}

.cover {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-size: cover;
    background-position: center;
    display: flex;
    justify-content: center;
    align-items: center;
    cursor: pointer;
    transition: opacity 0.3s ease;
    background-image: url("https://www.f139content.com/website/sci99/images/about/poster.png");
}

.cover.hidden {
    opacity: 0;
    pointer-events: none;
}

.play-btn {
    width: 50px;
    height: 50px;
}

.play-btn:hover {
    transform: scale(1.1);
}

.div_main .img-box {
    width: 600px;
    height: 330px;
    border-radius: 8px;
    overflow: hidden;
}

.div_main .img-box img {
    width: 100%;
    height: 100%;
}

.div_main .number-box {
    margin-top: 28px;
    white-space: nowrap;
}

.div_main .number-box .number-item {
    display: inline-block;
    margin-right: 106px;
}

.div_main .number-box .number-item:last-child {
    margin-right: 0;
}

.div_main .number-box .number-item .number span:first-child {
    font-family: PublicSans, sans-serif;
    font-weight: bold;
    font-size: 50px;
    color: #2050D1;
    line-height: 61px;
    text-align: justify;
}

.div_main .number-box .number-item .number span:last-child {
    font-family: PingFangSC, sans-serif;
    font-weight: 600;
    font-size: 20px;
    color: #2050D1;
    line-height: 28px;
    text-align: justify;
}

.div_main .number-box .number-item .text {
    margin-top: 10px;
    font-weight: 400;
    font-size: 16px;
    color: #666666;
    line-height: 24px;
    text-align: left;
}