body,
html {
  background-color: #071c55;
}
.case {
  position: relative;
  width: 100%;
  height: 100vh;
  background: url(../images/4.jpg) no-repeat top center;
}
.case_box_title {
  width: 100%;
  font-size: 45px;
  font-weight: bold;
  color: #fff;
  text-align: center;
  padding-top: 170px;
}

.blinds-container {
  display: flex;
  width: 90%;
  height: 510px;
  margin: 0 auto;
  margin-top: 50px;
  overflow: hidden;
  gap: 0.5%; /* 添加间隙防止贴边 */
}

.blind-item {
  position: relative;
  flex: 0 0 16%; /* 修改为固定基础尺寸 */
  transition: all 0.5s ease;
  background-size: cover;
  background-position: center;
  transform: translateZ(0); /* 优化动画性能 */
  user-select: none; /* 禁止文本选择 */
  -webkit-user-select: none; /* Safari兼容 */
  cursor: pointer; /* 统一鼠标样式 */
}
.blind-item_name {
  font-size: 20px;
  color: #fff;
  font-weight: bold;
  text-align: center;
  padding-top: 120px;
}
.blind-item.active {
  flex: 0 0 50%; /* 展开时占50%宽度 */
}

.content-layer {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  opacity: 0;
  transition: opacity 0.3s ease;
  display: flex;
  align-items: center;
  justify-content: center;

  font-weight: bold;
}
.content-inner-box {
  margin-top: 260px;
  color: #333;
}
.content-inner-box .content-inner-box-title {
  font-size: 24px;
  padding-bottom: 6px;
}
.content-inner-box .content-inner-box-com {
  font-size: 14px;
  font-weight: 400;
  text-align: justify;
  line-height: 22px;
}

.blind-item.active .content-layer {
  opacity: 1;
}

/* 为每个项目设置不同颜色 */
.blind-item:nth-child(1) .content-layer {
  background: url(../images/case01-big.jpg) no-repeat top center;
  color: black;
}
.blind-item:nth-child(2) .content-layer {
  background: url(../images/case02-big.jpg) no-repeat top center;
  color: white;
}
.blind-item:nth-child(3) .content-layer {
  background: url(../images/case03-big.jpg) no-repeat top center;
  color: white;
}
.blind-item:nth-child(4) .content-layer {
  background: url(../images/case04-big.jpg) no-repeat top center;
  color: white;
}

.content-inner {
  position: relative;
  text-align: center;
  max-width: 800px; /* 限制最大内容宽度 */
  width: 100%; /* 充满容器 */
  padding: 20px;
}

.close-btn {
  position: absolute;
  top: 10px;
  right: 20px;
  font-size: 2rem;
  cursor: pointer;
  display: none;
}

.blind-item.active .close-btn {
  display: block;
}