.concept {
  position: relative;
  width: 100%;
  padding: 2rem 0 3rem;
  background-color: #212121;
  background-image:
    url(../img/concept/bg-lead.png),
    url(../img/concept/bg-lead-left.png),
    url(../img/concept/bg-lead-left.png);
  background-position: top 66% center, center left, center right;
  background-size: 40% auto, 28% auto, 28% auto;
  background-repeat: no-repeat;
  z-index: 4;
}

.concept-top {
  position: relative;
  width: 100%;
  aspect-ratio: 1 / 0.02;
  background-image: url(../img/common/bg-btm.png);
  background-repeat: repeat-x;
  background-size: auto 100%;
  z-index: 4;
}

.concept-bottom {
  position: relative;
  width: 100%;
  aspect-ratio: 1 / 0.02;
  background-image: url(../img/common/bg-btm-2.png);
  background-repeat: repeat-x;
  background-size: auto 100%;
  z-index: 4;
}

.concept-heading {
  width: 100%;
  margin: 0 0 3rem;
  text-align: center;
}

.concept-heading img {
  width: 34%;
}

.lead {
  width: 50%;
  margin: 0 auto;
}

@media screen and (min-width: 1px) and (max-width: 743px) {
  .concept {
    position: relative;
    width: 100%;
    padding: 2rem 0 2rem;
    background-image:url(../img/concept/sp-bg-lead.png);
    background-position: center;
    background-size: 90% auto;
    background-repeat: no-repeat;
    z-index: 4;
  }

  .concept-top {
    aspect-ratio: 1 / 0.03;
  }

  .concept-bottom {
    aspect-ratio: 1 / 0.03;
  }

  .concept-heading {
    margin: 0 0 2rem;
  }

  .concept-heading img {
    width: 60%;
  }

  .lead {
    width: 90%;
  }
}

@media screen and (min-width: 744px) and (max-width: 1024px) {

  .concept-heading img {
    width: 38%;
  }

  .lead {
    width: 60%;
    margin: 0 auto;
  }
}