/* 首页横幅轮播 */
#page-header.full_page {
  position: relative;
  /* 横幅底部渐隐，融入全站背景，消除割裂感 */
  -webkit-mask-image: linear-gradient(to bottom, #000 78%, transparent 100%);
  mask-image: linear-gradient(to bottom, #000 78%, transparent 100%);
}

/* 全站背景压暗：弱化背景图的喧闹感，让卡片和横幅更突出 */
#web_bg::after {
  content: '';
  position: absolute;
  inset: 0;
  background: rgba(0, 0, 0, 0.22);
  pointer-events: none;
}

#page-header .banner-ghost {
  position: absolute;
  inset: 0;
  background-size: cover;
  background-position: center center;
  background-repeat: no-repeat;
  transition: opacity 1.2s ease;
  pointer-events: none;
  z-index: 0;
}

/* 保证标题和向下滚动按钮浮在轮播层之上 */
#page-header #site-info,
#page-header .scroll-down {
  position: relative;
  z-index: 1;
}