.main-banner .main-titile {
  font-size: 28px;
}
.main-banner .des {
  font-size: 15px;
  margin-bottom: 35px;
}
.main-banner .btn_down {
  font-size: 12px;
  padding: 5px 20px;
}
@media (min-width: 768px) {
  .main-banner .main-titile {
    font-size: 52px;
  }
  .main-banner .des {
    font-size: 25px;
    margin-bottom: 77px;
  }
  .main-banner .btn_down {
    font-size: 18px;
    padding: 8px 36px;
  }
}