* {
  padding: 0;
  margin: 0;
}

body {
  display: flex;
  overflow-x: scroll; 
  overflow-y: hidden;  /* 禁止竖直滚动 */
  /* height: 100vh !important; */
  width: 2880px; /* 这里设置body的宽度为视口宽度的两倍，因为你有两个页面。 */
  margin: 0;
  padding: 0;
}
section {
  width: 1440px; /* 这里设置iframe的宽度为其父元素（即body）的宽度。 */
  /* height: 100%; */
  border: none;
}


section {
  display: flex;
  justify-content: space-around;
  /* align-items: center; */
  /* min-height: 100vh; */

  /* background: #333; */
  background: #0f172a;
  background-image: url(https://xiabb.chat/assets/first_dark_bg-a4ba899b.jpg);
  background-size: cover;
  background-attachment: fixed;
  background-repeat: no-repeat;
}
 
.circle {
  cursor: pointer;
  overflow: hidden;
}

.container:hover {
  /*transform: scale(1.05);*/
  transition: transform 0.5s;
}

.circle:active {
  transform: translateY(1px);
}

.circle {
  width: 200px;
  height: 200px;
  /* background: black; */
  background-color: #ffffff26;
  border-radius: 50%;
}

.rectangle {
  opacity: 0;
  width: 200px;
  color: white;
  /* height: 200px; */
  /* background-color: black; */
  background-color: #ffffff26;

  opacity: 0;
  max-height: 0;
  overflow: hidden;
  transition: all 1s;
}
/* 
.rectangle_up {
    border-bottom-left-radius: 10px;
    border-bottom-right-radius: 10px;
}
.rectangle_down {
    border-top-left-radius: 10px;
    border-top-right-radius: 10px;
} 
*/
@keyframes slideDown {
  0% {
    opacity: 0;
    max-height: 0;
  }
  20% {
    opacity: 0;
    max-height: 0;
  }

  100% {
    opacity: 1;
    max-height: 300px;
  }
}

.rectangle p {
  padding: 12px;
  margin: 0;
  font-size: 16px;
  line-height: 1.4;
  font-weight: 600;
}

.circle_up {
  margin-top: 8vw;
}

.circle_up_img.expand {
  border-radius: 50% 50% 0 0;
}


.circle_down {
  margin-bottom: 8vw;
  display: flex;
  flex-direction: column-reverse;
}

.circle_down_img.expand {
  border-radius:  0 0 50% 50%;
}

.half_circle {
  width: 200px;
  height: 100px;
  background-color: #ffffff26;
  opacity: 0;
  transition: all 1s;
  text-align: center;
}

.half_circle_up {
  border-bottom-left-radius: 200px;
  border-bottom-right-radius: 200px;
}

.half_circle_down {
  border-top-left-radius: 200px;
  border-top-right-radius: 200px;
}

.half_circle.half_circle_down {
  padding-top: 1.3vw;
}

/* 
.container:hover + .rectangle {
  opacity: 1;
  transition: all 0.5s;
  animation: slideDown 0.5s forwards;
} 
*/


/* 
.circle_down_img:hover {
  border-radius:  0 0 50% 50%;
  transition: all 0.3s;
}

.circle_up_img:hover {
  border-radius: 50% 50% 0 0;
  transition: all 0.3s;
}
.circle:hover + .rectangle,
.circle:hover + .rectangle + .half_circle {
  opacity: 1;
  transition: all 0.5s;
  animation: slideDown 0.5s forwards;
}   
*/


.expand {
  opacity: 1;
  transition: all 0.5s;
  animation: slideDown 0.5s forwards;
} 



.model_item {
  display: block;
  font-family: iconfont;
  content: "";
  font-size: 120px !important;
  text-align: center;
  padding-top: 34px;
}
.model_item_1{
  color: #71a799;
}
.model_item_2{
  color: #4093d4;
}
.model_item_3{
  color: #1975ff;
}
.model_item_4{
  color: #738ba1;
}
.model_item_5{
  color: #4a4ab3;
}
.half_circle_icon{
  font-size: 50px !important;
  padding-top: 30px;
}

.btn-next {
  background: none;
  border: none;
  color: inherit;
  cursor: pointer;
  padding: 0;
  text-align: inherit;
  padding: 16px;
  border-radius: 12px;
  background-color: #ffffff26;
  color: white;
  font-size: 14px;
  font-weight: 600;
  transition: background-color 0.3s ease, transform 0.3s ease;
}

.btn-next:active {
  background-color: #ffffff66;
  transform: scale(0.95);
}



.title {
  text-align: center;
  padding-top: 10px;
  font-size: 28px;
  font-weight: 900;
  line-height: 60px;
}
.half_circle.half_circle_up {
  padding-top: -60px
}
.half_circle.half_circle_down {
  padding-top: 60px;
}
.title-down {
  padding-top: 16px;
}
.title-up {
  padding-top: 20px;
}