.banner img {
  width: 100%;
  height: auto;
}
.image_slide_1 {
  margin: 20px 0;
}
.image_slide_1 img {
  width: 100%;
  height: auto;
}
.section_hint {
  display: flex;
  width: 100%;
  margin: 3em 0;
  align-items: center;
}
.section_hint .video {
  width: 50%;
}
.section_hint .video video {
  width: 100%;
  height: auto;
}
.hint {
  margin-left: 2em;
}
.hint li {
  font-size: 1.1em;
}
.hint ol {
  margin-bottom: 2em;
}
@media only screen and (max-width: 650px) {
  .section_hint {
    flex-wrap: wrap;
  }
  .section_hint .video {
    width: 80%;
    margin: 2em auto;
  }
}