/* ==========================================================================
   站点导航栏样式 —— 全站唯一来源
   主站（Astro 页面）在 Layout.astro 里 <link> 引入；
   产品页（static HTML）在构建时由 scripts/sync-product-nav.mjs 注入 <link>。
   所有选择器都收在 .site-nav 之下，避免和产品页自己的样式互相污染。
   ========================================================================== */

.site-nav {
  /* 导航只依赖这几个变量，单独定义，不依赖各页面的 :root */
  --primary: #00897b;
  --text: #212121;
  --text-secondary: #616161;
  --border: #e0e0e0;
  --bg-gray: #f5f5f5;
  --shadow: 0 2px 12px rgba(0, 0, 0, 0.08);
  --shadow-lg: 0 8px 30px rgba(0, 0, 0, 0.12);

  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: rgba(255, 255, 255, 0.95);
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
  transition: all 0.3s;
  border-bottom: 1px solid transparent;
  font-family: -apple-system, BlinkMacSystemFont, 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'Source Han Sans SC', 'Noto Sans SC', sans-serif;
  line-height: 1.7;
  text-align: left;
}

.site-nav.scrolled {
  box-shadow: var(--shadow);
  border-bottom-color: var(--border);
}

.site-nav .header-inner {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 40px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}

.site-nav .logo { display: flex; align-items: center; }
.site-nav .logo-img { height: 68px; width: auto; }

.site-nav .nav-list { display: flex; gap: 6px; list-style: none; margin: 0; padding: 0; }
.site-nav .nav-item { position: relative; }

.site-nav .nav-item > a {
  display: block;
  padding: 24px 18px;
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--text);
  text-decoration: none;
  transition: color 0.3s;
}
.site-nav .nav-item > a:hover,
.site-nav .nav-item.active > a { color: var(--primary); }

.site-nav .nav-item.active::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 24px;
  height: 3px;
  background: var(--primary);
  border-radius: 2px;
}

.site-nav .dropdown {
  position: absolute;
  top: 100%;
  left: 50%;
  transform: translateX(-50%) translateY(10px);
  background: #fff;
  min-width: 160px;
  border-radius: 8px;
  box-shadow: var(--shadow-lg);
  padding: 8px 0;
  opacity: 0;
  visibility: hidden;
  transition: all 0.3s;
}
.site-nav .nav-item:hover .dropdown {
  opacity: 1;
  visibility: visible;
  transform: translateX(-50%) translateY(0);
}
.site-nav .dropdown a {
  display: block;
  padding: 10px 24px;
  font-size: 0.9rem;
  color: var(--text-secondary);
  text-decoration: none;
  white-space: nowrap;
}
.site-nav .dropdown a:hover { color: var(--primary); background: var(--bg-gray); }

.site-nav .nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
}

/* 菜单展开时锁住页面滚动（主站与产品页共用这一条） */
body.nav-open { overflow: hidden; }
.site-nav .nav-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--text);
  margin: 6px 0;
  transition: 0.3s;
}

@media (max-width: 768px) {
  .site-nav .header-inner { padding: 0 20px; }
  .site-nav .nav-list { display: none; }
  /* 静态产品页自带一份 `header.site-nav .nav-list{display:flex}`，特异性比
     `.site-nav .nav-list` 高、且它那份样式排在 site-nav.css 之后，
     会把桌面导航硬抬到手机屏幕上（导航条目被挤成 15px、汉堡按钮跑到屏幕外）。
     这里用三分类名双写提高特异性压回去。 */
  header.site-nav .nav-list.nav-list { display: none !important; }
  header.site-nav .main-nav.open .nav-list { display: flex !important; }
  header.site-nav .nav-item > a { padding: 13px 0; }
  header.site-nav .nav-item.active > a::after { display: none; }
  /* 移动端下拉菜单：
     1) 21 个链接堆起来接近 1250px，比手机屏（640~844）高，
        所以必须给 max-height + 内部滚动，否则底部「联系我们」永远点不到；
     2) 左右内边距收紧，二三级链接用左侧竖线区分层级；
     3) 当前页的下划线（::after）在竖排下会跑到中间，直接隐藏。 */
  .site-nav .main-nav.open .nav-list {
    display: flex;
    flex-direction: column;
    position: absolute;
    top: 72px;
    left: 0;
    right: 0;
    max-height: calc(100dvh - 72px);
    overflow-y: auto;
    -webkit-overflow-scrolling: touch;
    overscroll-behavior: contain;
    background: #fff;
    box-shadow: var(--shadow-lg);
    padding: 12px 20px calc(24px + env(safe-area-inset-bottom));
  }
  .site-nav .nav-toggle { display: block; }
  .site-nav .nav-item > a { padding: 13px 0; }
  .site-nav .nav-item.active > a::after { display: none; }
  .site-nav .dropdown {
    position: static;
    transform: none;
    opacity: 1;
    visibility: visible;
    box-shadow: none;
    padding: 2px 0 6px 14px;
    border-left: 2px solid var(--border);
    margin-left: 2px;
  }
  .site-nav .dropdown a { padding: 9px 8px; }
}