.container {
  overflow-x: hidden;
}
.part {
  padding: 0 30px;
}

.banner_part {
  position: relative;
  overflow: hidden;
  min-width: 100vw;
  max-width: 100vw;
  height: calc((100vw * 9 / 16) - 80px);
  /* max-height: calc(100vh - 80px); */
  max-height:100vh;
  min-height: 666px;
  background-color: #272727;
}

.banner {
  position: absolute;
  left: 0;
  top: 0;
  width: 100%;
  height: 100%;
}
.banner > video {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.banner_content {
  position: relative;
  z-index: 2;
  height: 100%;
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.banner_title {
  font-size: 48px;
  background-color: #000000;
  color: #ffff;
  margin-bottom: 20px;
  width: fit-content;
  padding: 5px 20px;
  font-weight: 300;
  letter-spacing: 2px;
}
.banner_des {
  font-size: 20px;
  background-color: #dddde4;
  color: #000;
  width: fit-content;
  padding: 5px;
  font-weight: 300;
  letter-spacing: 2px;
}

.about_part {
  background-color: #000;
  padding: 80px 30px;
}
.about_box {
  display: flex;
  align-items: center;
  justify-content: space-between;
  color: #fff;
}
.about_part_l > h2 {
  font-size: 50px;
  margin-bottom: 20px;
}
.about_part_l > p {
  font-size: 14px;
  margin-bottom: 30px;
  letter-spacing: 2px;
}

.presentation_part{
  padding: 50px 0;
}
/* presentation_item */
.presentation_item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 50px 0;
}
.presentation_item:nth-child(2n) {
  /* 置换顺序位置 */
  flex-flow: row-reverse;
}

.presentation_item_l,
.presentation_item_r {
  width: 45%;
}
.presentation_item_l {
  display: flex;
  justify-content: start;
}
.presentation_item:nth-child(2n) .presentation_item_l {
  justify-content: end;
}

.presentation_item_r {
  /* max-width: 570px; */
}

.presentation_image {
  cursor: pointer;
  /* width: 40vw; */
  /* max-width: 500px; */
  /* max-height: 400px; */
  /* height: calc(40vw * 4 / 5); */
  overflow: hidden;
  background-color: #272727;
  /* background: #2f80af; */
  transition: 0.3s ease;
  transform-origin: background-color;
}

.presentation_image > video {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.presentation_image:hover {
  /* background-color: #2F80AF; */
}

.presentation_image > img {
  width: 100%;
  height: 100%;
  object-fit: contain;
}

.presentation_name {
  font-size: 50px;
  letter-spacing: 2px;
}

.presentation_des {
  font-weight: lighter;
  letter-spacing: 2px;
  line-height: 40px;
  padding: 30px 0 60px 0;
}

.presentation_item_btn {
  position: relative;
  z-index: 2;
  cursor: pointer;
  width: 240px;
  height: 60px;
  line-height: 59px;
  background-color: #000;
  color: #ffff;
  text-align: center;
  letter-spacing: 2px;
  font-weight: 300;
  overflow: hidden;
  border: 1px solid #fff;
}

.presentation_item_btn:hover::after {
  opacity: 1;
  transform: translate3d(0, 0, 0);
}
.presentation_item_btn::after {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  z-index: -1;
  width: 100%;
  height: 100%;
  background-color: #2ba0e3;
  transform: translate3d(-70%, 0, 0);
  transition: 0.3s ease;
  opacity: 0;
  transform-origin: transform opacity;
}

/* person_part */
.person_bg {
  position: absolute;
  left: 0;
  width: 100%;
  /* filter: blur(2px); */
  opacity: 0.9;
  top: 50%;
  transform: translateY(-50%);
}
.person_part {
  position: relative;
  overflow: hidden;
  background-color: #e9e5e6;
  padding: 120px 30px 200px 30px;
}
.person_box {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.person_part_l > h2 {
  width: fit-content;
  background-color: #fff;
  padding: 5px 10px;
  font-size: 50px;
  letter-spacing: 2px;
  margin-bottom: 18px;
}
.person_part_l > p {
  background-color: #fff;
  padding: 5px 10px;
  width: fit-content;
  margin-bottom: 5px;
}
.person_btn {
  user-select: none;
  border: none;
  margin-top: 50px;
}

.person_switch_box {
  height: 725px;
  display: flex;
  align-items: center;
}
.switch_box {
  position: relative;
  height: 100%;
}
.switch_box > img {
  height: 100%;
}

.move_in {
  animation: move_in var(--s) ease forwards;
}
@keyframes move_in {
  from {
    opacity: 0;
    transform: translateX(-100%);
  }
  to {
    opacity: 1;
    transform: translateX(0%);
  }
}
.move_out {
  animation: move_out var(--s) ease forwards;
}
@keyframes move_out {
  from {
    opacity: 1;
    transform: translateX(0%);
  }
  to {
    opacity: 0;
    transform: translateX(100%);
  }
}

/* contect_part */
.contect_part {
  display: flex;
  justify-content: space-around;
}

.enter_box {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  width: 100%;
  padding: 120px 0;
  color: #fff;
  letter-spacing: 3px;
  cursor: pointer;

  will-change: transform;
  transition: 0.3s ease;
  transform-origin: transform;
}
.enter_box.active {
  z-index: 2;
  transform: scale(3);
}
.enter_box > p {
  font-size: 30px;
  font-weight: 300;
}
.enter_box_one {
  background-color: #2ba0e3;
}
.enter_box_two {
  background-color: #000000;
}

.enter_title {
  display: flex;
  align-items: center;
  padding-bottom: 10px;
}
.enter_title > h2,
.enter_title > p {
  font-size: 40px;
  font-weight: 300;
}

.enter_box:hover .is_enter {
  opacity: 1;
  transform: translate3d(5px, -5px, 0) rotate(10deg);
}
.is_enter {
  opacity: 0;
  transition: 0.3s ease;
  transform-origin: opacity transform;
}

/* frame */
.contact_frame {
  position: fixed;
  z-index: 99;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  display: none;
}
.contact_frame.active {
  display: block;
  animation: show_frame 0.3s ease;
}
@keyframes show_frame {
  0% {
    opacity: 0;
  }
  100% {
    opacity: 1;
  }
}

/* group_part */
.group_part {
  background-color: #d3d3d5;
}
.group_image {
  width: 100%;
  height: 100%;
}
.group_image > img {
  width: 100%;
  height: 100%;
}

/* mobile */
@media screen and (max-width: 767px) {
  .banner_title {
    font-size: 32px;
  }
  .banner_des {
    font-size: 20px;
  }
  .about_box {
    flex-direction: column;
  }
  .about_part_l {
    width: 100%;
    /* margin-bottom: 50px; */
  }

  .about_part_l > h2 {
    font-size: 30px;
  }
  .about_part_l > p {
    font-size: 14px;
    margin-bottom: 14px;
  }
  .about_part_r {
    width: 100%;
  }
  .presentation_item_btn {
    width: 100%;
  }

  .presentation_part {
    padding: 30px;
  }
  .presentation_item {
    flex-direction: column;
    padding-bottom: 50px;
  }
  .presentation_item:nth-child(2n) {
    /* 置换顺序位置 */
    flex-flow: unset;
    flex-direction: column;
  }
  .presentation_item:nth-child(2n) .presentation_item_l {
    justify-content: unset;
  }
  .presentation_item_l,
  .presentation_item_r {
    width: 100%;
    max-width: 100%;
  }
  .presentation_item_l {
    display: flex;
    justify-content: center;
    margin-bottom: 40px;
  }
  .presentation_image {
    width: 100vw;
    max-width: 100%;
    /* height: calc(90vw * 4 / 5); */
  }
  .presentation_name {
    font-size: 30px;
  }
  .presentation_des {
    padding: 10px 0 20px 0;
    line-height: 40px;
    font-size: 14px;
    font-weight: 300;
  }
  .contect_part {
    flex-direction: column;
  }
  .enter_box {
    padding: 30px 0;
  }
  .enter_title > h2,
  .enter_title > p {
    font-size: 24px;
  }
  .enter_box > p {
    font-size: 18px;
  }

  .person_part {
    position: relative;
  }
  .person_box {
    position: unset;
  }
  .person_part_l {
    position: relative;
    z-index: 2;
    margin-top: 200px;
  }
  .person_part_r {
    position: absolute;
    width: 100%;
    left: 0;
  }
  .person_switch_box {
    justify-content: center;
    height: 500px;
  }
}