.main {
  padding-top: 90px;
  padding-bottom: 80px;
}

.knowledge1 {
  display: -webkit-flex;
  display: flex;
  -webkit-align-items: center;
  align-items: center;
}

.knowledge1 .txt {
  -webkit-flex: 1;
  flex: 1;
  margin-right: 80px;
}

.knowledge1 .txt h1 {
  font-size: 34px;
  color: #2e2e2e;
  line-height: 1;
  font-weight: 700;
}

.knowledge1 .txt p {
  color: #666;
  font-size: 18px;
  line-height: 2.2;
  margin: 20px 0 0;
}

.knowledge1 .txt p strong {
  color: #333;
}

.knowledge1 ul {
  width: 50%;
  display: -webkit-flex;
  display: flex;
  -webkit-justify-content: space-between;
  justify-content: space-between;
}

.knowledge1 ul li {
  width: calc(50% - 10px);
}

.knowledge1 ul li:last-child {
  margin-top: 30px;
}

.knowledge2 {
  padding: 120px 0;
  display: -webkit-flex;
  display: flex;
  -webkit-align-items: center;
  align-items: center;
}

.knowledge2 .pic {
  width: 580px;
  display: -webkit-flex;
  display: flex;
  -webkit-align-items: center;
  align-items: center;
  position: relative;
}

.knowledge2 .pic::after {
  content: "";
  background: #F8F8F8;
  position: absolute;
  left: 0;
  top: -30px;
  bottom: -30px;
  width: 430px;
}

.knowledge2 .pic h3 {
  writing-mode: vertical-rl;
  padding: 0 25px;
  font-size: 75px;
  color: #eaeaea;
  font-weight: bold;
  letter-spacing: 10px;
  text-align: center;
  position: relative;
  z-index: 10;
}

.knowledge2 .pic dl {
  width: 430px;
  position: relative;
  z-index: 10;
}

.knowledge2 .pic dl dd+dd {
  margin-top: 10px;
}

.knowledge2 .txt {
  -webkit-flex: 1;
  flex: 1;
  margin-left: 80px;
}

.knowledge2 .txt ul {}

.knowledge2 .txt ul li {
  display: -webkit-flex;
  display: flex;
}

.knowledge2 .txt ul li+li {
  margin-top: 170px;
}

.knowledge2 .txt ul li em {
  width: 43px;
  height: 43px;
  line-height: 43px;
  text-align: center;
  background: #212121;
  font-size: 20px;
  color: #fff;
  font-weight: bold;
  display: block;
}

.knowledge2 .txt ul li .t {
  -webkit-flex: 1;
  flex: 1;
  margin-left: 27px;
}

.knowledge2 .txt ul li .t h5 {
  font-size: 24px;
  color: #2e2e2e;
  line-height: 43px;
  font-weight: 700;
}

.knowledge2 .txt ul li .t p {
  color: #666;
  font-size: 18px;
  line-height: 2;
  margin: 5px 0 0;
}

.knowledge3 {
  display: -webkit-flex;
  display: flex;
  -webkit-align-items: center;
  align-items: center;
}

.knowledge3 .txt {
  -webkit-flex: 1;
  flex: 1;
  margin-right: 150px;
}

.knowledge3 .txt h3 {
  font-size: 34px;
  color: #2e2e2e;
  line-height: 1;
  font-weight: 700;
}

.knowledge3 .txt p {
  color: #666;
  font-size: 18px;
  line-height: 2.2;
  margin: 20px 0 0;
}

.knowledge3 .txt p strong {
  color: #333;
}

.knowledge3 .pic {
  width: 44.7%;
  overflow: hidden;
}

.knowledge3 .pic img {
  border-radius: 30px 30px 30px 0;
}

.knowledge4 {
  padding: 100px 0;
  background: url(https://okki-shop.oss-cn-hangzhou.aliyuncs.com/category/346014/279/a642a7f174423b1de15396bb39e19dff/1.jpg) no-repeat center;
}

.knowledge4 .wp {
  border-bottom: 1px solid #ccc;
  padding: 50px 0;
  display: -webkit-flex;
  display: flex;
  -webkit-align-items: center;
  align-items: center;
}

.knowledge4 .txt {
  -webkit-flex: 1;
  flex: 1;
  margin-right: 160px;
}

.knowledge4 .txt h3 {
  font-size: 30px;
  color: #333;
  line-height: 1;
  font-weight: 700;
}

.knowledge4 .txt p {
  color: #666;
  font-size: 18px;
  line-height: 1.8;
  margin: 20px 0 0;
}

.knowledge4 .more {
  width: 238px;
  position: relative;
}

@keyframes scale2 {
  from {
    top: 0;
    right: 0;
    bottom: 0;
    left: 0;
  }

  50% {
    top: -10px;
    right: -10px;
    bottom: -10px;
    left: -10px;
  }

  to {
    top: 0;
    right: 0;
    bottom: 0;
    left: 0;
  }
}

.knowledge4 .more::after {
  content: "";
  position: absolute;
  border-radius: 35px;
  background: rgba(0, 0, 21, 0.15);
  animation: scale2 1.5s linear infinite;
}

.knowledge4 .more a {
  color: #fff;
  font-size: 18px;
  width: 100%;
  height: 56px;
  line-height: 56px;
  border-radius: 35px;
  background: var(--btn-bg);
  display: inline-block;
  text-align: center;
  position: relative;
  z-index: 20;
}

.knowledge4 .more a:hover {
  background: var(--btn-bg-hover);
}

@media screen and (max-width:1550px) {
  .knowledge2 .txt ul li em {
    width: 40px;
    height: 40px;
    line-height: 40px;
    font-size: 18px;
  }

  .knowledge2 .txt ul li .t h5 {
    font-size: 22px;
    line-height: 40px;
  }

  .knowledge2 .txt ul li .t p {
    line-height: 1.6;
    margin: 2px 0 0;
  }
}

@media screen and (max-width:1400px) {
  .main {
    padding-top: 70px;
    padding-bottom: 60px;
  }

  .knowledge1 .txt h1,
  .knowledge3 .txt h3 {
    font-size: 32px;
  }

  .knowledge2 .txt {
    margin-left: 60px;
  }

  .knowledge2 .txt ul li em {
    width: 36px;
    height: 36px;
    line-height: 36px;
    font-size: 17px;
  }

  .knowledge2 .txt ul li .t h5 {
    font-size: 20px;
    line-height: 36px;
  }

  .knowledge2 .txt ul li .t p {
    line-height: 1.5;
  }

  .knowledge3 .txt {
    margin-right: 80px;
  }

  .knowledge4 {
    padding: 80px 0;
  }

  .knowledge4 .wp {
    padding: 40px 0;
  }
}

@media screen and (max-width:992px) {
  .main {
    padding-top: 30px;
    padding-bottom: 20px;
  }
}

@media screen and (max-width:768px) {
  .main {
    padding-top: 20px;
  }

  .knowledge1 .txt h1,
  .knowledge3 .txt h3 {
    font-size: 28px;
  }

  .knowledge1 {
    -webkit-flex-direction: column;
    flex-direction: column;
  }

  .knowledge1 .txt {
    margin-right: 0;
  }

  .knowledge1 .txt h1 {
    text-align: center;
  }

  .knowledge1 .txt p {
    font-size: 16px;
    line-height: 1.4;
    margin: 15px 0 0;
  }

  .knowledge1 ul {
    width: 100%;
    margin: 20px 0 0;
  }

  .knowledge1 ul li:last-child {
    margin-top: 0;
  }

  .knowledge2 {
    padding: 30px 0;
    -webkit-flex-direction: column;
    flex-direction: column;
  }

  .knowledge2 .pic {
    width: 100%;
    -webkit-flex-direction: column;
    flex-direction: column;
  }

  .knowledge2 .pic::after {
    display: none;
  }

  .knowledge2 .pic h3 {
    writing-mode: horizontal-tb;
    padding: 0;
    font-size: 30px;
    color: #2e2e2e;
    letter-spacing: 0;
    text-align: center;
  }

  .knowledge2 .pic dl {
    width: 100%;
    margin: 20px 0 0;
    position: relative;
    z-index: 10;
    display: -webkit-flex;
    display: flex;
    -webkit-justify-content: space-between;
    justify-content: space-between;
  }

  .knowledge2 .pic dl dd {
    width: 48%;
  }

  .knowledge2 .pic dl dd+dd {
    margin-top: 0;
  }

  .knowledge2 .txt {
    width: 100%;
    margin: 20px 0 0;
  }

  .knowledge2 .txt ul li+li {
    margin-top: 15px;
  }

  .knowledge2 .txt ul li em {
    width: 30px;
    height: 30px;
    line-height: 30px;
    font-size: 16px;
  }

  .knowledge2 .txt ul li .t {
    margin-left: 20px;
  }

  .knowledge2 .txt ul li .t h5 {
    font-size: 18px;
    line-height: 30px;
  }

  .knowledge2 .txt ul li .t p {
    font-size: 16px;
    line-height: 1.4;
  }

  .knowledge3 {
    -webkit-flex-direction: column;
    flex-direction: column;
  }

  .knowledge3 .txt {
    margin-right: 0;
  }

  .knowledge3 .txt h3 {
    text-align: center;
  }

  .knowledge3 .txt p {
    font-size: 16px;
    line-height: 1.4;
    margin: 15px 0 0;
  }

  .knowledge3 .pic {
    width: 100%;
    margin: 20px 0 0;
  }

  .knowledge4 {
    padding: 30px 0;
  }

  .knowledge4 .wp {
    padding: 0 10px;
    -webkit-flex-direction: column;
    flex-direction: column;
    border-bottom: none;
  }

  .knowledge4 .txt {
    -webkit-flex: 1;
    flex: 1;
    margin-right: 0;
    width: 100%;
    text-align: center;
  }

  .knowledge4 .txt h3 {
    font-size: 24px;
  }

  .knowledge4 .txt p {
    font-size: 16px;
    line-height: 1.4;
    margin: 15px 0 0;
  }

  .knowledge4 .more {
    width: 200px;
    margin: 20px 0 0;
  }

  .knowledge4 .more a {
    font-size: 16px;
    height: 48px;
    line-height: 48px;
  }
}

@media screen and (max-width:600px) {

  .knowledge1 .txt h1,
  .knowledge3 .txt h3 {
    font-size: 25px;
  }
}


@media screen and (max-width:480px) {

  .knowledge1 .txt h1,
  .knowledge3 .txt h3 {
    font-size: 24px;
  }
}