.header-wrapper{
  width:100%;
  position:relative;
  background:rgb(29,29,29);
}
.header-box{
  position:relative;
  z-index:99;
}

.header-wrapper .header-bg{
  width:100%;
}

.header-content{
  position:absolute;
  top:0;
  right:0;
  bottom:0;
  left:0;
}

.header-content .big-logo{
  margin-left:21.7%;
  width:18%;
  height:100%;
  display:flex;
  align-items:center;
}

.header-content .big-logo img{
  width:100%;
}

.desc-box{
  position:absolute;
  top:50%;
  transform:translateY(-50%);
  right:20.4%;
  color:#fff;
  width:574px;
}

.desc-box h2{
  font-size:26px;
  margin-bottom:15px;
}
.desc-box .subtitle{
  font-size:18px;
  margin:10px 0
}

.desc-box .article{
  font-size:14px;
  line-height:24px;
  text-align:justify;
  color:rgb(212, 209, 209);
}
.desc-box .down-load{
  background:#3D9CE1;
  width:100%;
  text-align:center;
  height:40px;
  line-height:40px;
  font-size:16px;
  margin-top:70px;
  cursor:pointer;
}

.down-load a{
  text-decoration:none;
  color:#fff;
}

.content{
  padding-top:80px;
}

.w-center{
  width:62.5%;
  margin:0 auto;
}

.section-gap{
  margin-top:120px;
}

.section-title{
  text-align:center;
  padding-bottom:12px;
  border-bottom:1px solid #dbdbdb;
}
.section-title p{
  font-size:24px;
  color:#333;
}

.option{
  width:100%;
  display:flex;
  margin-top:27px;
}
.opt-item{
  width:25%;
  height:406px;
  padding-top:45px;
  color:#333;
}
.opt-item:nth-child(odd){
  background:#f0f0f0;
}
.item-title{
  text-align:center;
  font-size:32px;
}
.icon{
  width:120px;
  height:120px;
  margin:150px auto 0;
}

.opt-item .num{
  font-size:80px;
  color:#262626;
  opacity:0.2;
  text-align:center;
}
.opt-item .advantage{
  color:#262626;
  font-size:40px;
  text-align:center;
  margin:110px 0 45px;
}
.opt-item .txt{
  color:#262626;
  font-size:24px;
  text-align:center;
  margin-bottom:14px;
}

.concat{
  padding:80px 0;
  text-align:center;
}
.concat p{
  color:#7e7e7e;
  font-size:24px;
}

.footer{
  background:#f0f0f0;
  text-align:center;
  padding:26px 0;
}
.footer p{
  color:#7e7e7e;
  font-size:12px;
  margin:10px 0;
}

.footer p a{
  color:#7e7e7e;
}

@media screen and (max-width:1200px) {
  .desc-box{
    width: 47.6%;
    right: 3.4%;
  }
  .header-content .big-logo{
    margin-left: 7.7%;
  }
}

@media screen and (max-width:800px) {
  .desc-box{
    width:100%;
    padding:0 15px;
    position:static;
    transform:translateY(0);
  }
  .header-content .big-logo{
    display:none;
  }
  .desc-box .down-load{
    margin-top: 20px;
  }
  .header-content{
    display:flex;
    align-items:center;
    padding-top: 54px;
  }
  .option{
    flex-wrap:wrap;
  }
  .opt-item{
    width:50%;
    height: 260px;
    padding-top:34px;
  }
  .icon{
    margin: 30px auto 0;
  }
  .opt-item:nth-child(3){
    background: #fff;
  }
  .opt-item:nth-child(4){
    background: #f0f0f0;
  }
  .section-gap{
    margin-top:24px;
  }
  .opt-item .advantage{
    margin: 12px 0 18px;
    font-size:24px;
  }
  .opt-item .txt{
    font-size:16px;
  }
}

@media screen and (max-width:560px){
  .desc-box h2,.desc-box .subtitle{
    display:none;
  }
  .desc-box .article{
    line-height:16px;
    font-size:12px;
  }
  .desc-box .down-load{
    margin-top:10px;
    height: 36px;
    line-height: 36px;
    font-size: 14px;
  }
}