body {
  font-family: "Helvetica Neue",
    Arial,
    "Hiragino Kaku Gothic ProN",
    "Hiragino Sans",
    Meiryo,
    sans-serif;
}

#hero {
  background: url('https://placehold.jp/1280x720.png') no-repeat center center/cover;
  height: 70vh;
}

.form-group {
  margin-bottom: 1rem;
}

.over-left {
  margin-left: -120px;
  background: #fff;
}

.over-right {
  margin-right: -120px;
  background: #fff;
}

@media (max-width: 768px) {
  #hero {
    height: 50vh;
  }
  .over-left {
    margin-left: 0px;
  }
  .over-right {
    margin-right: 0px;
  }
}