.intro_content {
  width: 100%;
  margin: 0 auto;
  padding-top: 40px;
}
.intro_content .content_items {
  width: 100%;
  margin: 0 auto;
}
.intro_content .content_items .content_item {
  margin-bottom: 70px;
  border: 1px solid transparent;
}
.intro_content .content_items .knowledge{
    margin-bottom: 0 !important;
}

.intro_content .content_items .content_item .item_title {
  width: 100%;
  text-align: center;
  display: -webkit-flex;
  display: flex;
  -webkit-justify-content: center;
  justify-content: center;
  margin: 30px 0;
}
.content_item .item_title span {
  position: relative;
  float: left;
  font: 60px '宋体';
  font-weight: 300;
  line-height: 1;
  color: #63c7f2;
  padding-right: 9px;
}
.content_item .item_title span::before {
  content: '';
  display: block;
  position: absolute;
  top: 8px;
  right: 0;
  width: 2px;
  height: 80%;
  background-color: #63c7f2;
}
.content_item .item_title .title_text {
  float: left;
  text-align: left;
  padding-left: 10px;
}
.content_item .item_title .title_text h2,
.content_item .item_title .title_text p {
  margin: 0;
  color: #4a4a4a;
}
.content_item .item_title .title_text h2 {
  font-size: 30px;
}
.content_item .item_title .title_text p {
  font-size: 20px;
  text-transform: uppercase;
}
.content_item .item_title::after {
  content: '';
  display: block;
  clear: both;
}
.item_1 {
  width: 70%;
  margin: 0 auto;
}
.item_1 .item_1_top .top_1_left {
  width: 63%;
  float: left;
  font-size: 16px;
  line-height: 1.6;
  margin-right: 2%;
}
.item_1 .item_1_top .top_1_left p {
  text-indent: 2em;
}
.item_1 .item_1_top .top_1_right {
  width: 35%;
  float: right;
  position: relative;
}
.jianjie-swiper img{
    display: block;
    width: 100%;
    height: auto;
}
.item_1 .item_1_top .top_1_right video {
  display: block;
  width: 100%;
}
.item_1 .item_1_top .top_1_right .video_mask {
  position: absolute;
  top: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.5);
  display: flex;
  display: -webkit-flex;
  justify-content: center;
  -webkit-justify-content: center;
  align-items: center;
  opacity: 1;
  transition: all 2.2s;
  z-index: 99;
}
.item_1 .item_1_top .top_1_right .video_mask img {
  width: 15%;
  height: auto;
}
.item_1 .item_1_top::after {
  content: '';
  display: block;
  clear: both;
}
.item_1 .item_1_bottom {
  margin-top: 30px;
}
.item_1 .item_1_bottom ul li {
  float: left;
  width: 20%;
  text-align: center;
}
.item_1 .item_1_bottom ul li .li_1_img {
  display: block;
  width: 30%;
  border-radius: 50%;
  padding: 10px;
  margin: 0 auto;
  margin-bottom: 15px;
  box-shadow: 0px 11px 30px 8px rgba(240, 240, 240, 0.75);
}
.item_1 .item_1_bottom ul li .li_1_img img {
  display: block;
  width: 100%;
  height: auto;
}
.item_1 .item_1_bottom ul::after {
  content: '';
  clear: both;
  display: block;
}
.item_2 {
  width: 100%;
}
.item_2 .item_2_top p {
  width: 50%;
  line-height: 1.5;
  font-size: 16px;
  margin: 0 auto;
  margin-bottom: 30px;
}

.item_2 .item_2_bottom {
  text-align: center;
}

.item_2_bg {
  background: #f5f5f5;
}
.item_3 .item_3_top p {
  width: 39%;
  line-height: 1.5;
  font-size: 16px;
  margin: 0 auto;
  margin-bottom: 30px;
}
.item_3 .item_3_middle {
  width: 70%;
  margin: 0 auto;
  margin-bottom: 30px;
}
.item_3 .item_3_middle ul li {
  float: left;
  width: 25%;
  padding: 0 2%;
  box-sizing: border-box;
}
.item_3 .item_3_middle ul li .li_item {
  transition: all 0.5s;
}
.item_3 .item_3_middle ul li .li_item .li_img img {
  width: 100%;
  display: block;
  height: auto;
}
.item_3 .item_3_middle ul li .li_item .li_text {
  background-color: #f4f4f4;
  box-sizing: border-box;
  padding: 10px;
  color: #939393;
}
.item_3 .item_3_middle ul li .li_item .li_text h4 {
  margin-bottom: 10px;
  color: #5d5d5d;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.item_3 .item_3_middle ul li .li_item .li_text p {
  display: -webkit-box;
  overflow: hidden;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
}
.item_3 .item_3_middle ul li .li_item:hover {
  transform: scale(1.01);
  box-shadow: 0px 8px 22px 2px #bbbbbb;
}
.item_3 .item_3_middle ul li .li_item:hover .li_text {
  background-color: #63c7f2;
  color: #fff;
}
.item_3 .item_3_middle ul li .li_item:hover .li_text p,
.item_3 .item_3_middle ul li .li_item:hover .li_text h4 {
  color: #fff;
}
.item_3 .item_3_middle ul::after {
  content: '';
  display: block;
  clear: both;
}
.gd_btn {
  width: 13%;
  border: 1px solid transparent;
  background-color: #63c7f2;
  border-radius: 16px;
  margin: 0 auto;
  text-align: center;
  margin-top: 30px;
  padding: 5px;
  color: #fff;
}
.gd_btn a {
  color: #fff;
}
.item_3 .item_3_bottom {
  position: relative;
}
.item_3 .item_3_bottom .item_3_img img {
  display: block;
  width: 100%;
  height: auto;
}
.item_3 .item_3_bottom .item_3_img img:nth-of-type(2) {
  display: none;
}
.item_3 .item_3_bottom .item_3_mask {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  width: 100%;
}
.item_3 .item_3_bottom .item_3_mask .mask_img {
    display: block;
  width: 585px;
  margin: 50px auto;
}
.item_3 .item_3_bottom .item_3_mask .mask_img img {
  display: block;
  width: 100%;
  height: auto;
}
.item_3 .item_3_bottom .item_3_mask .mask_text {
  margin: 0 auto;
  text-align: center;
  font: 25px '宋体';
  color: #fff;
}
.item_3 .item_3_bottom .item_3_mask .mask_text span {
  display: inline-block;
  transform: translate(-1300px, -550px);
}
.item_3
  .item_3_bottom
  .item_3_mask
  .mask_text
  .mask_active
  span:nth-of-type(1) {
  animation: flyInLeftTop 1.83s ease;
  animation-fill-mode: forwards;
}
.item_3
  .item_3_bottom
  .item_3_mask
  .mask_text
  .mask_active
  span:nth-of-type(2) {
  animation: flyInLeftTop 1.7s ease;
  animation-fill-mode: forwards;
}
.item_3
  .item_3_bottom
  .item_3_mask
  .mask_text
  .mask_active
  span:nth-of-type(3) {
  animation: flyInLeftTop 1.53s ease;
  animation-fill-mode: forwards;
}
.item_3
  .item_3_bottom
  .item_3_mask
  .mask_text
  .mask_active
  span:nth-of-type(4) {
  animation: flyInLeftTop 1.94s ease;
  animation-fill-mode: forwards;
}
.item_3
  .item_3_bottom
  .item_3_mask
  .mask_text
  .mask_active
  span:nth-of-type(5) {
  animation: flyInLeftTop 1.97s ease;
  animation-fill-mode: forwards;
}
.item_3
  .item_3_bottom
  .item_3_mask
  .mask_text
  .mask_active
  span:nth-of-type(6) {
  animation: flyInLeftTop 1.8s ease;
  animation-fill-mode: forwards;
}
.item_3
  .item_3_bottom
  .item_3_mask
  .mask_text
  .mask_active
  span:nth-of-type(7) {
  animation: flyInLeftTop 1.75s ease;
  animation-fill-mode: forwards;
}
.item_3
  .item_3_bottom
  .item_3_mask
  .mask_text
  .mask_active
  span:nth-of-type(8) {
  animation: flyInLeftTop 1.91s ease;
  animation-fill-mode: forwards;
}
.item_3
  .item_3_bottom
  .item_3_mask
  .mask_text
  .mask_active
  span:nth-of-type(9) {
  animation: flyInLeftTop 1.64s ease;
  animation-fill-mode: forwards;
}
.item_3
  .item_3_bottom
  .item_3_mask
  .mask_text
  .mask_active
  span:nth-of-type(10) {
  animation: flyInLeftTop 1.78s ease;
  animation-fill-mode: forwards;
}
.item_3
  .item_3_bottom
  .item_3_mask
  .mask_text
  .mask_active
  span:nth-of-type(11) {
  animation: flyInLeftTop 1.95s ease;
  animation-fill-mode: forwards;
}
.item_3
  .item_3_bottom
  .item_3_mask
  .mask_text
  .mask_active
  span:nth-of-type(12) {
  animation: flyInLeftTop 1.9s ease;
  animation-fill-mode: forwards;
}
.item_3
  .item_3_bottom
  .item_3_mask
  .mask_text
  .mask_active
  span:nth-of-type(13) {
  animation: flyInLeftTop 1.82s ease;
  animation-fill-mode: forwards;
}
.item_3
  .item_3_bottom
  .item_3_mask
  .mask_text
  .mask_active
  span:nth-of-type(14) {
  animation: flyInLeftTop 1.87s ease;
  animation-fill-mode: forwards;
}
.item_3
  .item_3_bottom
  .item_3_mask
  .mask_text
  .mask_active
  span:nth-of-type(15) {
  animation: flyInLeftTop 1.68s ease;
  animation-fill-mode: forwards;
}
.item_3
  .item_3_bottom
  .item_3_mask
  .mask_text
  .mask_active
  span:nth-of-type(16) {
  animation: flyInLeftTop 1.64s ease;
  animation-fill-mode: forwards;
}
.item_3
  .item_3_bottom
  .item_3_mask
  .mask_text
  .mask_active
  span:nth-of-type(17) {
  animation: flyInLeftTop 1.81s ease;
  animation-fill-mode: forwards;
}
.item_3
  .item_3_bottom
  .item_3_mask
  .mask_text
  .mask_active
  span:nth-of-type(18) {
  animation: flyInLeftTop 1.66s ease;
  animation-fill-mode: forwards;
}
.item_3
  .item_3_bottom
  .item_3_mask
  .mask_text
  .mask_active
  span:nth-of-type(19) {
  animation: flyInLeftTop 1.71s ease;
  animation-fill-mode: forwards;
}
.item_3
  .item_3_bottom
  .item_3_mask
  .mask_text
  .mask_active
  span:nth-of-type(20) {
  animation: flyInLeftTop 1.91s ease;
  animation-fill-mode: forwards;
}
@keyframes flyInLeftTop {
  0% {
    transform: translate(-1300px, -550px);
  }
  100% {
    transform: translate(0, 0);
  }
}
.item_4 .item_4_left {
  width: 40%;
  float: left;
  text-align: right;
  margin-top: 100px;
}
.item_4 .item_4_left .item_4_title {
  float: right;
  width: 100%;
  margin-bottom: 35px;
}
.item_4 .item_4_left .item_4_title span {
  position: relative;
  float: right;
  font: 60px '宋体';
  font-weight: 300;
  line-height: 1;
  color: #63c7f2;
  padding-right: 9px;
}
.item_4 .item_4_left .item_4_title span::before {
  content: '';
  display: block;
  position: absolute;
  top: 8px;
  right: 0;
  width: 2px;
  height: 82%;
  background-color: #63c7f2;
}
.item_4 .item_4_left .item_4_title span:nth-of-type(1) {
  display: none;
}
.item_4 .item_4_left .item_4_title .title_text {
  float: right;
  text-align: left;
  padding-left: 10px;
}
.item_4 .item_4_left .item_4_title .title_text h2,
.item_4 .item_4_left .item_4_title .title_text p {
  margin: 0;
  color: #4a4a4a;
}
.item_4 .item_4_left .item_4_title .title_text h2 {
  font-size: 30px;
}
.item_4 .item_4_left .item_4_title .title_text p {
  font-size: 20px;
  text-transform: uppercase;
}
.item_4 .item_4_left .item_4_title::after {
  content: '';
  display: block;
  clear: both;
}
.item_4 .item_4_left ul {
  width: 100%;
  float: right;
}
.item_4 .item_4_left ul li {
  line-height: 1.8;
  font-size: 18px;
}
.item_4 .item_4_right {
  width: 33%;
  float: left;
  padding: 10px;
  margin-left: 2%;
  box-sizing: border-box;
}
.item_4 .item_4_right .right_4_top .top_4_item {
  width: 49%;
  float: left;
  margin: 0.5%;
  box-sizing: border-box;
  position: relative;
  overflow: hidden;
}
.item_4 .item_4_right .right_4_top .top_4_item img {
  display: block;
  width: 100%;
  height: auto;
}
.item_4 .item_4_right .right_4_top .top_4_item span {
  position: absolute;
  bottom: 0;
  line-height: 35px;
  text-align: center;
  width: 100%;
  color: #fff;
  background-color: rgba(99, 199, 242, 0.8);
  transition: all 0.7s;
  transform: translateY(100%);
  opacity: 0;
}
.item_4 .item_4_right .right_4_top .top_4_item:hover span {
  transform: translateY(0);
  opacity: 1;
}
.item_4 .item_4_right .right_4_top::after {
  content: '';
  display: block;
  clear: both;
}
.item_4 .item_4_right .right_4_bottom .bottom_4_item {
  width: 32.33%;
  float: left;
  position: relative;
  margin: 0.5%;
  box-sizing: border-box;
  overflow: hidden;
}
.item_4 .item_4_right .right_4_bottom .bottom_4_item img {
  display: block;
  width: 100%;
  height: auto;
}
.item_4 .item_4_right .right_4_bottom .bottom_4_item span {
  position: absolute;
  bottom: 0;
  width: 100%;
  line-height: 35px;
  text-align: center;
  color: #fff;
  background-color: rgba(99, 199, 242, 0.8);
  transition: all 0.7s;
  transform: translateY(100%);
  opacity: 0;
}
.item_4 .item_4_right .right_4_bottom .bottom_4_item:nth-of-type(3) span {
  height: 100%;
  line-height: unset;
  padding-top: 60%;
  box-sizing: border-box;
}
.item_4 .item_4_right .right_4_bottom .bottom_4_item:hover span {
  transform: translateY(0);
  opacity: 1;
}
.item_4 .item_4_right .right_4_bottom::after {
  content: '';
  display: block;
  clear: both;
}
.item_4::after {
  content: '';
  display: block;
  clear: both;
}
@media screen and (max-width: 1600px) {
  .item_4 .item_4_left {
    margin-top: 40px;
  }
}
@media screen and (max-width: 1444px) {
  .item_1 {
    width: 85%;
  }
  .item_1 .item_1_top .top_1_left {
    width: 58%;
    margin-right: 1%;
    font-size: 16px;
  }
  .item_1 .item_1_top .top_1_right {
    width: 40%;
  }
  .item_1 .item_1_bottom ul li img {
    width: 40%;
  }
  .item_4 .item_4_left {
    width: 45%;
    margin-top: 30px;
  }
  .item_4 .item_4_right {
    width: 40%;
  }
  .item_3 .item_3_bottom .item_3_mask .mask_img {
    width: 17%;
    margin: 75px auto;
  }
  .item_2 .item_2_top p,
  .item_3 .item_3_top p {
    width: 55%;
  }
}
@media screen and (max-width: 1200px) {
  .item_1 {
    width: 90%;
  }
  .item_3 .item_3_middle {
    width: 90%;
  }
}
@media screen and (max-widht: 1144px) {
  .item_4 .item_4_left {
    margin-top: 6px;
  }
}
@media screen and (max-width: 1010px) {
  .item_1,
  .item_3 .item_3_middle {
    width: 96%;
  }
  .item_3 .item_3_bottom .item_3_mask .mask_img {
    width: 19%;
    margin: 50px auto;
  }
}
@media screen and (max-width: 950px) {
  .item_1 .item_1_top .top_1_left {
    width: 90%;
    float: unset;
    margin-right: 0;
    margin: 0 auto;
    font-size: 18px;
  }
  .item_1 .item_1_top .top_1_right {
    width: 70%;
    margin: 0 auto;
    float: unset;
    margin-top: 20px;
  }
  .item_2 .item_2_top p,
  .item_3 .item_3_top p {
    width: 75%;
  }
  .item_4 .item_4_right {
    width: 46%;
  }
  .item_4 .item_4_left {
    width: 52%;
    margin-top: 10px;
  }
  .item_4 .item_4_left .item_4_title {
    margin-bottom: 10px;
  }
  .item_4 .item_4_left ul li {
    line-height: 1.5;
    font-size: 16px;
  }
}
@media screen and (max-width: 768px) {
  .item_1,
  .item_3 .item_3_middle {
    width: 90%;
  }
  .item_1 .item_1_top .top_1_right,
  .item_1 .item_1_top .top_1_left {
    width: 100%;
  }
  .item_1 .item_1_top .top_1_left {
    margin-top: 20px;
  }
  .item_1 .item_1_bottom ul li .li_1_img {
    width: 66%;
  }

  .item_2 .item_2_bottom img{
    width: 100%;
  }

  .item_3 .item_3_middle ul li {
    float: left;
    width: 50%;
    padding: 0 1%;
    margin-bottom: 2%;
  }
  .item_3 .item_3_bottom .item_3_mask .mask_img {
      display: none;
    margin: 60px auto;
    width: 45%;
  }
  .gd_btn {
    width: 15%;
    margin-top: 15px;
  }
  .item_3 .item_3_bottom .item_3_img img:nth-of-type(1) {
    display: none;
  }
  .item_3 .item_3_bottom .item_3_img img:nth-of-type(2){
    display: block;
  }
  .intro_content {
    padding-top: 0;
  }
  .item_4 .item_4_left .item_4_title {
    text-align: center;
  }
  .item_4 .item_4_left .item_4_title span:nth-of-type(1) {
    display: inline-block;
    float: none;
  }
  .content_item .item_title span,
  .item_4 .item_4_left .item_4_title span:nth-of-type(1) {
    font: 48px '宋体';
    line-height: 50px;
  }
  .content_item .item_title .title_text h2,
  .item_4 .item_4_left .item_4_title .title_text h2 {
    font-size: 24px;
    font-weight: 200;
  }
  .content_item .item_title .title_text p,
  .item_4 .item_4_left .item_4_title .title_text p {
    font-size: 16px;
  }
  .item_4 .item_4_left .item_4_title span:nth-of-type(2) {
    display: none;
  }
  .item_4 .item_4_left .item_4_title .title_text {
    float: none;
    display: inline-block;
  }
  .item_4 .item_4_left ul li {
    font-size: 20px;
  }
  .item_4 .item_4_right {
    width: 90%;
    margin: 0 auto;
    float: none;
  }
  .item_4 .item_4_left .item_4_title .title_text h2 {
    font-size: 25px;
  }
  .item_4 .item_4_left .item_4_title .title_text p {
    font-size: 13px;
    line-height: 22px;
  }
  .item_4 .item_4_left {
    width: 90%;
    margin-top: 10px;
    margin: 0 auto;
    float: unset;
  }
  .item_4 .item_4_left::after {
    content: '';
    display: block;
    clear: both;
  }
  .item_4 .item_4_left ul {
    width: 100%;
    text-align: center;
  }
  .intro_content .content_items .content_item {
    margin-bottom: 0;
  }
  .item_4 .item_4_left .item_4_title {
    text-align: center;
    margin: 30px 0;
  }
}
@media screen and (max-width: 668px) {
  .item_3 .item_3_bottom .item_3_mask .mask_text {
    font: 22px '宋体';
  }
  .item_2 .item_2_top p,
  .item_3 .item_3_top p {
    width: 90%;
  }
  .item_1 .item_1_top .top_1_left {
    font-size: 17px;
  }
  .gd_btn {
    width: 20%;
  }
}
@media screen and (max-width: 540px) {
  .item_4 .item_4_left ul li {
    font-size: 16px;
  }
  .item_1 .item_1_bottom ul li .li_1_img {
    width: 70%;
  }
}
@media screen and (max-width: 414px) {
  .item_4 .item_4_left,
  .item_1,
  .item_3 .item_3_middle,
  .item_4 .item_4_right {
    width: 96%;
  }
  .item_1 .item_1_bottom ul li span {
    font-size: 14px;
  }
  .item_1 .item_1_top .top_1_left p {
    font-size: 16px;
  }
  .item_3 .item_3_middle ul li .li_item .li_text p {
    font-size: 14px;
  }
  .item_1 .item_1_bottom ul li .li_1_img {
    width: 70%;
    margin-bottom: 5px;
  }
  .item_1 .item_1_bottom {
    margin-bottom: 30px;
  }
  .gd_btn {
    width: 100px;
  }
}
@media screen and (max-width: 375px) {
  .item_4 .item_4_left ul li {
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
  }
}