@media screen and (max-width: 768px) {
  body {
    padding-bottom: 40px;
  }
  .pc-kefu {
    display: none;
  }
  .mob-btn {
    position: fixed;
    bottom: 20px;
    width: 100%;
    display: flex;
  }
  .mob-btn .btn2 {
    height: 40px;
    font-size: 19px;
    padding: 0px;
    width: 50%;
    color: #fff;
    background: #2889e4;
    border-radius: 5px;
    border: none;
  }
  .mob-btn .mob-tel {
    width: 50%;
    background: #2889e4;
    font-size: 19px;
    color: #fff;
    line-height: 40px;
    text-align: center;
    border-radius: 5px;
  }
}

@media screen and (min-width: 768px) {
  .mob-btn {
    display: none;
  }
}