.first-image {
  width: 100%;
  background: #000;
  opacity: 0;
  
}
.header-title {
  width: 100%;
  display: inline-block;
  text-align: center;
  margin-top: 130px;
  margin-left: 620px;
  max-width: 400px;
  color: #fff;
}
.fristcn {
  text-align: center;
  transition-delay: 0.8s !important;
}
.header-title img {
  width: 73%;
  margin-bottom: 10px;
}
.header-title .header-dec {
  width: 100%;
  font-size: 32px;
  margin-top: 20px;
  margin-bottom: 48px;
}
.header-title .header-name {
  width: 100%;
  margin-top: 65px;
  font-size: 74px;

}
@media only screen and (max-width: 767px) {
  .fristcn {
    text-align: left;
  }

  .header-title {
    text-align: right;
    margin-top: 0;
    margin-left: 0;
  }
  .header-title img {
    width: 35%;
    margin-bottom: 0;
  }
  .header-title img {
    margin-bottom: 0;
  }
  .header-title .header-dec {
    font-size: 10px;
    margin-bottom: 0;
    margin-top: 0;
  }
  .header-title .header-name {
    font-size: 14px;
    margin-top: 0;
  }
}
.describe {
  width: 100%;
  height: 600px;
  background: #000;
  color: #fff;
  display: flex;
  align-items: center; /*定义body的元素垂直居中*/
  justify-content: center;
}
.describe p {
  width: 60%;
  text-align: center;
  line-height: 60px;
  font-size: 28px;
}
@media only screen and (max-width: 767px) {
  .describe {
    width: 100%;
    height: 150px;
  }
  .describe p {
    width: 100%;
    line-height: 18px;
    font-size: 10px;
  }
}
.content_frist {
  background: #000;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}
.content_frist img {
  width: 90%;
}
.content_frist .desc {
  width: 90%;
  font-size: 32px;
  line-height: 72px;
  padding-top: 50px;
}
@media only screen and (max-width: 767px) {
  .content_frist .desc {
    font-size: 14px;
    line-height: 30px;
  }
}
.content_second {
  height: 850px;
  background: #000;
  padding-top: 100px;
  display: flex;
  align-items: center;
  justify-content: center;
}
.content_second img {
  width: 35%;
  float: left;
}
.content_second .desc {
  background-color: rgba(0, 0, 0, 0.5);
  width: 48%;
  float: left;
  font-size: 32px;
  line-height: 68px;
  margin-left: -66px;
  margin-top: 256px;
}
@media only screen and (max-width: 767px) {
  .content_second {
    height: 400px;
    padding-top: 20px;
    display: flex;
    flex-direction: column;
  }
  .content_second img {
    width: 50%;
  }
  .content_second .desc {
    width: 100%;
    font-size: 14px;
    line-height: 20px;
    margin-left: 0;
    margin-top: 20px;
  }
}
.content_three {
    position: relative;
  width: 100%;
  height: 1200px;
  background: #000;
  padding-top: 100px;
}
.content_three .three_title {
    width: 38%;
    font-size: 63px;
    font-weight: bold;
    display: flex;
    align-items: center;
    justify-content: center;
    height: 116px;
    transition-delay: 0.3s;
}
.three_item {
    position: absolute;
    top: 280px;
    left: 0;
    width: 100%;
    height: 700px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition-delay: 0.6s;
}
.three_item img {
  width: 75%;
}
.three_item .three_one,
.three_two,
.three_three {
  width: 65%;
  height: 765px;
  display: flex;
  flex-direction: column;
  justify-content: space-around;
  align-items: center;
}
.three_item p {
  text-align: center;
  font-size: 20px;
}
@media only screen and (max-width: 767px) {
  .content_three {
    height: 1140px;
    padding-top: 10px;
    
  }
  .content_three .three_title {
    width: 100%;
    font-size: 25px;
    display: flex;
    align-items: center;
    justify-content: center;
  }
  .three_item {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
  }
  .three_item img {
    width: 80%;
  }
  .three_item .three_one,
  .three_two,
  .three_three {
    width: 60%;
    padding-top: 30px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
  }
  .three_item p {
    font-size: 13px;
  }
}
.books{
    position: relative;
    background: #000;
    height: 1500px;
}
.books .books_title{
    width: 100%;
    font-size: 63px;
    font-weight: bold;
    display: flex;
    align-items: center;
    justify-content: right;
    height: 116px;
}
.books_item{
width: 100%;
}
.books_item .one{
    width: 68%;
    padding-top: 224px;
    padding-left: 255px;
}
.books_item .two{
    width: 40%;
    padding-top: 157px;
    padding-left: 798px;
}
.books_item .three{
width: 68%;
padding-top: 176px;
padding-left: 150px;
}
.books_item .four{
width: 42%;
padding-top: 185px;
padding-left: 620px;
}
.books_item .five{
width: 60%;
padding-top: 175px;
padding-left: 55px;
}
@media only screen and (max-width: 767px) {
    .books{
        height: 500px;
    }
    .books .books_title{
        font-size: 30px;
        justify-content: center;
    }
    .books_item .one{
        padding-top: 50px;
        padding-left: 50px;
    }
    .books_item .two{

        padding-top: 50px;
        padding-left: 110px;
    }
    .books_item .three{
        padding-top: 50px;
        padding-left: 50px;
    }
    .books_item .four{

        
        padding-top: 50px;
        padding-left: 110px;
    }
    .books_item .five{
        padding-top: 50px;
        padding-left: 50px;

    }
}
.footer {
    background: #000;
    width: 100%;
    height: 500px;
    display: flex;
    align-items: center;
    justify-content: center;
  }
  .footer  img{
      width: 15%;
  }
  @media only screen and (max-width: 767px){
 
    .footer{
        height: 200px;
    }
    .footer  img{
        width: 35%;
    }
  }