.header {
  height: 326px;
  background: #15d69e;
  color: #fff;
  text-align: center;
}
.header h1 {
  font-weight: 650;
  font-style: normal;
  color: #F0EFEF;
  font-size: 32px;
  padding: 90px 0 30px;
  margin: 0;
}
.header h3 {
  font-size: 24px;
  font-weight: 650;
  font-style: normal;
  color: #F0EFEF;
}
.to-user-letter {
  box-sizing: border-box;
  width: 1120px;
  margin: -100px auto 0;
  padding: 40px 100px;
  background: #eef7fc;
  border-radius: 5px;
}
.to-user-letter h3 {
  font-weight: 650;
  font-style: normal;
  color: #000000;
  font-size: 24px;
}
.to-user-letter p {
  text-indent: 2em;
  font-size: 18px;
  color: #797979;
  line-height: 32px;
  margin-top: 40px;
}
.develop-course {
  padding: 60px 0;
}
.develop-course .title {
  text-align: center;
  font-weight: 650;
  font-style: normal;
  color: #15D69E;
  font-size: 32px;
}
.develop-course .course {
  width: 325px;
  margin: 40px auto 0;
  position: relative;
  left: 125px;
}
.develop-course .course > div h4 {
  font-size: 20px;
  color: #15D69E;
  font-style: normal;
  font-weight: 400;
  padding: 15px 0;
  margin: 0;
  position: relative;
}
.develop-course .course > div h4:before {
  content: '';
  position: absolute;
  width: 20px;
  height: 20px;
  background: #15d69e;
  border-radius: 50px;
  left: -60px;
  top: 50%;
  transform: translateY(-50%);
}
.develop-course .course > div p {
  height: 110px;
  font-size: 14px;
  position: relative;
  margin: 0;
  color: #333333;
}
.develop-course .course > div p:before {
  content: '';
  position: absolute;
  left: -50px;
  top: 0;
  bottom: 0;
  width: 1px;
  background: #15d69e;
}
.develop-course .course > div:first-child h4:after {
  content: '';
  box-sizing: border-box;
  position: absolute;
  width: 50px;
  height: 50px;
  top: 50%;
  left: -75px;
  transform: translateY(-50%);
  border: 1px solid #15d69e;
  border-radius: 50px;
}
.develop-course .course > div:last-child p:after {
  content: '';
  position: absolute;
  border-top: 8px solid #15d69e;
  border-left: 8px solid transparent;
  border-right: 8px solid transparent;
  bottom: 0;
  left: -58px;
}
.join-us {
  width: 1154px;
  margin: 80px auto 20px;
}
.join-us .title {
  position: relative;
  margin-bottom: 50px;
}
.join-us .title:before {
  content: '';
  position: absolute;
  left: 50%;
  bottom: -20px;
  transform: translateX(-50%);
  width: 70px;
  height: 1px;
  background: #14D69E;
}
.join-us > div {
  margin-bottom: 10px;
  justify-content: space-between;
}
.join-us > div > div {
  display: flex;
  flex-direction: column;
  width: 550px;
  height: 266px;
}
.join-us > div > div:first-child {
  align-items: center;
  justify-content: center;
  background: #f2f2f2;
  font-weight: 650;
  color: #333;
}
.join-us > div > div:first-child .logo {
  line-height: 1;
}
.join-us > div > div:first-child .logo img {
  width: 39px;
  margin-right: 10px;
}
.join-us > div > div:first-child .logo p {
  font-size: 25px;
}
.join-us > div > div:first-child .logo span {
  font-size: 15px;
}
.join-us > div > div:last-child {
  box-sizing: border-box;
  background: #14d69e;
  color: #fff;
  padding: 30px;
  font-size: 16px;
  line-height: 32px;
}
.join-us > div > div:last-child h3 {
  font-size: 20px;
  font-weight: 600;
  margin-bottom: 40px;
}