.sche_img {
  margin: 100px auto;
  display: -webkit-box;
  display: -ms-flexbox;
  display: flex;
  -ms-flex-wrap: wrap;
      flex-wrap: wrap;
  -webkit-box-pack: justify;
      -ms-flex-pack: justify;
          justify-content: space-between;
}
.sche_img .box {
  width: 48%;
}
.sche_img img {
  width: 100%;
  height: auto;
}

@media screen and (max-width: 800px) {
  .sche_img .box {
    width: 100%;
    margin-bottom: 3em;
  }
}