.app_desc {
  margin-top: 20px;
  text-align: center;
  font-size: 20px;
  color: #3ddc9c;
}
#detail {
  background: #F5F6F7;
  width: 100%;
  display: flex;
  justify-content: center;
}
#detail .d_con {
  width: 1200px;
  text-align: center;
  padding: 20px 0;
}
#detail .d_con img {
  width: 300px;
}