.slider-img {
  margin-top: 60px;
  height: 100%;
  width: 100%;
}

.context-area {
  padding: 60px 0;
}

.dark {
  background: #F4F5F9;
}

.title {
  text-align: center;
  margin-bottom: 60px;
}

.type-flex {
  position: relative;
  display: inline-flex;
  margin: 0 auto;
}

.type-item img {
  height: 116px;
  margin: 0 125px;
}

.type-item h4 {
  margin-top: 30px;
  display: block;
}

.content {
  margin-right: 4%;
  display: inline-flex;
  text-align: center;
}

.advantage-content {
  width: 452px;
}

.advantage-right {
  margin-left: 10%;
}

.advantage-content h3, p {
  text-align: left;
}

.advantage-content p {
  margin-top: 30px;
}

.future {
  margin: 70px 13% 0 13%; 
}

.lesson-area {
  margin: 0 30px;
}

.lesson {
  width: 100%;
  overflow-x: scroll;
}

.class-img {
  margin: 0 30px 0 0; 
}

.slider {
  position: absolute;
  width: 40px;
  background: rgba(0,0,0,0.30);
  height: 260px;
  line-height: 260px;
}

.slider span {
  color: #fff;
}

.to-front {
  left: 30px;
  z-index: 9;
}

.to-back {
  right: 30px;
  z-index: 10;
}