.ppcb-top-banner {
  height: 600px;
  background: url(https://lstyty.oss-cn-hangzhou.aliyuncs.com/51tyty/officialWebsite/productService/jxiaofw/img_school_home_banner.png)
    no-repeat center center;
  background-size: cover;
}
.ppcb-top-banner .free-use-btn {
  width: 222px;
  height: 70px;
  line-height: 70px;
  font-size: 20px;
  border-radius: 36px;
  margin-left: 0;
  margin-top: 60px;
}
.index-free-box {
  overflow: hidden;
}
.banner-title {
  /* width: 320px; */
  height: 112px;
  font-size: 80px;
  color: #ffffff;
  line-height: 112px;
  font-weight: 600;
  margin-top: 160px;
  margin-bottom: 30px;
}
.banner-info {
  width: 588px;
  height: 33px;
  font-size: 24px;
  color: #ffffff;
  line-height: 33px;
  letter-spacing: 4px;
}
.ppcb-top-banner .shadow-btn {
  width: 222px;
  height: 70px;
  background: #fff;
  opacity: 0.2;
  border-radius: 36px;
  position: absolute;
  top: 9px;
  left: 10px;
}

.zsyx-box li:nth-child(odd){
  background: #fff;
}
.zsyx-box li:nth-child(even){
  background: #F9FAFF;
}


.flex-box {
  width: 1200px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin: 0 auto;
}
.img1 {
  margin: 112px 0;
  width: 714px;
  height: 452px;
}
.img2 {
  margin: 112px 0;
  width: 714px;
  height: 449px;
}
.img3 {
  margin: 112px 0;
  width: 730px;
  height: 602px;
}
.img4 {
  margin: 112px 0;
  width: 730px;
  height: 602px;
}

.item-title { 
  color: #333333;
  font-weight: 600;
  font-size: 36px;
}
.item-content {
  color: #222222;
  font-size: 26px;
  margin: 16px 0 30px 0;
}
.videoBtn {
  width: 186px;
  height: 48px;
  font-size: 16px;
  line-height: 48px;
  border: 1px solid #3097FF;
  border-radius: 24px;
  color: #1890FF;
  text-align: center;
  cursor: pointer;
  margin: 0 auto;
}
.right-video {
  float: right;
}
.left-video {
  float: left;
}

.qrcodeAndBtn {
  display: flex;
  justify-content: flex-end;
}
.qrcodeBox {
  width: 162px;
  box-sizing: border-box;
  padding: 10px;
  background: #F2F2F2;
  border-radius: 14px;
  text-align: center;
}
.qrcodeAndBtn img {
  width: 142px;
  height: 142px;
  margin-bottom: 10px;
}
.qrcodeTitle {
  color: #222222;
  font-size: 20px;
}
.specialBtn {
  margin: 0;
  margin-right: 23px;
}

@media screen and (max-width: 1440px) {
  .ppcb-top-banner {
    height: 450px;
  }
  .ppcb-top-banner .free-use-btn {
    width: 166px;
    height: 52px;
    line-height: 52px;
    font-size: 15px;
    margin-top: 44px;
  }
  .free-use-btn img {
    width: 12px;
    height: 13px;
    margin-top: -2px;
  }
  .banner-title {
    /* width: 240px; */
    height: 84px;
    font-size: 60px;
    color: #ffffff;
    line-height: 84px;
    font-weight: 600;
    margin-bottom: 23px;
    margin-top: 120px;
  }
  .banner-info {
    width: 441px;
    height: 25px;
    font-size: 18px;
    color: #ffffff;
    line-height: 25px;
    letter-spacing: 3px;
  }
  .ppcb-top-banner .shadow-btn {
    width: 166px;
    height: 52px;
    line-height: 52px;
    top: 6px;
    left: 7px;
  }
  
  .flex-box {
    width: 900px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin: 0 auto;
  }
  .img1 {
    margin: 84px 0;
    width: 536px;
    height: 339px;
  }
  .img2 {
    margin: 84px 0;
    width: 536px;
    height: 338px;
  }
  .img3 {
    margin: 84px 0;
    width: 501px;
    height: 413px;
  }
  .img4 {
    margin: 84px 0;
    width: 531px;
    height: 440px;
  }
  
  .item-title { 
    font-size: 30px;
  }
  .item-content {
    font-size: 20px;
    margin: 16px 0 20px 0;
  }

  .videoBtn {
    width: 140px;
    height: 36px;
    font-size: 14px;
    line-height: 36px;
    border-radius: 18px;
  }

  .qrcodeAndBtn {
    display: flex;
    justify-content: flex-end;
  }
  .qrcodeBox {
    width: 121px;
    box-sizing: border-box;
    padding: 8px;
    background: #F2F2F2;
    border-radius: 11px;
    text-align: center;
  }
  .qrcodeAndBtn img {
    width: 107px;
    height: 107px;
    margin-bottom: 6px;
  }
  .qrcodeTitle {
    font-size: 16px;
  }
  .specialBtn {
    margin: 0;
    margin-right: 21px;
  }

}