/* ===== 三级导航条（专题页顶部固定菜单）=====
   全局加载，任意页面 URL 命中导航树才渲染。样式全部钉死（px + !important），
   不继承页面字号/字体/链接色，保证在项目任何页面里外观一致不受干扰 */
body .topic-subnav {
  position: fixed !important;
  top: 64px !important;
  left: 0 !important;
  right: 0 !important;
  z-index: 998 !important; /* 低于 .header(999)：hover 一级菜单的下拉面板自然盖住三级条 */
  background: rgba(255, 255, 255, 0.8) !important; /* 半透明磨砂 */
  -webkit-backdrop-filter: blur(20px) !important;
  backdrop-filter: blur(20px) !important;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.04) !important;
  transition: top 0.3s ease;
  margin: 0 !important;
  padding: 0 !important;
}
body .topic-subnav * {
  box-sizing: border-box !important;
  margin: 0 !important;
  padding: 0 !important;
  font-family: '微软雅黑', 'HarmonyOS Sans SC', 'HarmonyOS_Sans_SC', sans-serif !important;
}
body .topic-subnav__inner {
  display: flex !important;
  align-items: center !important;
  justify-content: center !important;
  gap: 56px !important;
  height: 44px !important;
  max-width: 1920px !important;
  margin: 0 auto !important;
  background: transparent !important;
}
body .topic-subnav__item {
  display: inline-block !important;
  font-size: 14px !important;
  font-weight: 400 !important;
  line-height: 1 !important;
  letter-spacing: normal !important;
  color: #1D1D1F !important;
  text-decoration: none !important;
  white-space: nowrap !important;
  transition: color 0.2s !important;
}

/* ===== 滚动隐藏主导航（仅渲染了三级条的页面，由 topic-subnav.js 给 body 加 .subnav-scrolled）=====
   滚动 >120px：主导航上滑隐藏、三级条吸顶；回到顶部(<80px)恢复主导航 */
.header {
  transition: transform 0.3s ease;
}
.subnav-scrolled .header {
  transform: translateY(-100%) !important;
}
.subnav-scrolled .topic-subnav {
  top: 0 !important;
}
body .topic-subnav__item {
  border: none !important;
  background: transparent !important;
}
body .topic-subnav__item:hover,
body .topic-subnav__item.active {
  color: #999999 !important;
  text-decoration: none !important;
}
/* 页面主体让位：body 加类后首屏下移 */
body.topic-subnav-page {
  padding-top: 44px !important;
}