html, body {
  margin: 0;
  padding: 0;
  width: 100svw;
  height: 100svh;
  overflow-x: hidden;
  overflow-y: hidden;
}

.container {
  width: 100%;
  min-height: 100vh;
  min-height: 100svh; /* safe viewport height for mobile browsers */
  box-sizing: border-box;
  background: #ffffff;
  background-size: cover;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: flex-start; /* 垂直居中整个内容组 */
  gap: 10px;
}
.top{
  width: 100%;
  margin-top: 6%;
}
.top-logo{
  width: 50%;
  margin: 0 auto;
  img{
    width: 100%;
  }
}

.center{
  width: 100%;
  height: 100svh;
  /* 禁止长按时选中文字，避免和“保存图片”冲突 */
  user-select: none;
  -webkit-user-select: none;
  -webkit-touch-callout: none;
}

/* .demo-wrapper {
  position: relative;
  display: inline-block;
} */

.center .demo{
  width: 100%;
  height: 100svh;
  object-fit: contain;
  /* 禁止图片被选中、拖拽，长按只触发保存 */
  user-select: none;
  -webkit-user-select: none;
  -webkit-user-drag: none;
  pointer-events: auto;
}


.bottom{
  width: 100%;
  height: 22%;
  position: absolute;
  bottom: 0;
}

.bottom_text_1{
  width: 130px;
  position: absolute;
  bottom: 18svh;
  left: 50%;
  transform: translateX(-53%);
  img{
    width: 100%;
  }
}
.bottom-btn{
  width: 130px;
  position: absolute;
  bottom: 11svh;
  left: 50%;
  transform: translateX(-53%);
  img{
    width: 100%;
  }
}
.bottom_text_2{
  width: 210px;
  position: absolute;
  bottom: 5svh;
  left: 50%;
  transform: translateX(-53%);
  img{
    width: 100%;
  }
}