.sub_visual_area {
  position: relative;
  width: 100%;
  height: 302px;
  background: url("../../images/main/visual01.jpg") no-repeat;
  background-position: center center;
  background-size: cover;
}

.sub_visual_box {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  width: 100%;
  height: 100%;
  justify-content: flex-end;
}

.sub_visual_box h2 {
  position: relative;
  color: #fff;
  font-size: 60px;
  font-weight: 800;
  line-height: 90%;
  width: 90%;
  max-width: 1200px;
  margin: 0 auto;
  text-align: center;
  padding-bottom: 50px;
}

.sub_content {
  position: relative;
  width: 90%;
  max-width: 1200px;
  padding: 4rem 0;
  margin: 0 auto;
}

.sub_header_btn {
  position: relative;
  width: 100%;
  background: #13172f;
}

.sub_header_btn ul {
  display: flex;
  flex-direction: row;
  flex-wrap: nowrap;
  align-items: center;
  justify-content: space-between;
  width: 90%;
  max-width: 1200px;
  margin: 0 auto;
}

.sub_header_btn ul li {
  width: calc(100% / 2);
}

.sub_header_btn ul li a {
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 15px;
  color: rgba(255, 255, 255, 0.5);
  height: 72px;
  border-left: 1px solid rgba(255, 255, 255, 0.2);
  border-bottom: 5px solid #13172f;
}

.sub_header_btn ul li:last-of-type a {
  border-right: 1px solid rgba(255, 255, 255, 0.2);
}

.sub_menu_on {
  border-bottom: 5px solid #3770fb !important;
  color: #fff !important;
}

/*************************introducition****************************/

.vision,
.structure {
  max-width: 1280px;
}

.vision_img,
.structure_img {
  width: 100%;
}

/*************************media****************************/

@media screen and (max-width: 1080px) {
  .sub_visual_area {
    background-position: right 30% center;
  }
}

@media screen and (max-width: 640px) {
  .sub_visual_area {
    height: 260px;
  }
  .sub_visual_box h2 {
    font-size: 44px;
  }
  .sub_header_btn ul li a {
    height: 60px;
  }
}

@media screen and (max-width: 500px) {
  .sub_visual_area {
    background-position: right 20% center;
  }
  .sub_visual_area {
    height: 240px;
  }
  .sub_visual_box h2 {
    font-size: 40px;
  }
  .sub_header_btn ul li a {
    height: 54px;
  }
}

@media screen and (max-width: 440px) {
  .sub_visual_area {
    height: 220px;
  }
  .sub_visual_box h2 {
    font-size: 34px;
  }
  .sub_header_btn ul li a {
    height: 44px;
  }
}

@media screen and (max-width: 330px) {
  .sub_visual_area {
    height: 200px;
  }
  .sub_visual_box h2 {
    font-size: 30px;
  }
  .sub_header_btn ul li a {
    height: 40px;
  }
}