/* ============================================================
   导航下拉菜单 — 方案 C 混合型
   二级分组标题 + 三级国旗链接网格，居中收窄面板
   ============================================================ */

/* ── 下拉外层容器 ── */
.nav-cont {
  position: absolute;
  top: 100%;
  left: 0;
  width: 100%;
  z-index: 1000;
  overflow: hidden;
  transition: height 0.25s ease-out;
  height: 0;
  pointer-events: none; /* 左右空白区域不拦截鼠标 */
}

/* ── 下拉内层 —— 居中收窄面板 ── */
.nav-dropdown-inner {
  display: flex;
  justify-content: center;
  padding: 0;
}

/* ── 每个一级导航对应的菜单面板 ── */
.nav-cont-menu {
  display: none;
  width: 100%;
  max-width: 900px;
  margin: 0 auto;
  background: rgba(14, 16, 26, 0.98);
  backdrop-filter: blur(24px);
  -webkit-backdrop-filter: blur(24px);
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-top: none;
  border-radius: 0 0 14px 14px;
  box-shadow: 0 20px 48px rgba(0, 0, 0, 0.55),
              0 0 0 1px rgba(255, 255, 255, 0.04) inset;
  padding: 20px 0 12px;
  pointer-events: auto; /* 只有实际内容区域可交互 */
}

.nav-cont-menu.nav-cont-empty {
  display: none !important;
}

/* ── 分组容器 (方案 C 核心) ── */
.nav-groups {
  padding: 0 24px;
}

.nav-group {
  margin-bottom: 8px;
}

.nav-group:last-child {
  margin-bottom: 0;
}

/* ── 二级分组标题行 ── */
.nav-group-title {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 8px 6px;
  font-size: 12px;
  font-weight: 600;
  color: rgba(148, 163, 184, 0.7);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  border-bottom: 1px solid rgba(255, 255, 255, 0.05);
  margin-bottom: 6px;
  user-select: none;
}

.nav-group-icon {
  width: 18px;
  height: 18px;
  object-fit: contain;
  opacity: 0.7;
}

.nav-group-desc {
  font-weight: 400;
  font-size: 11px;
  color: rgba(148, 163, 184, 0.45);
  letter-spacing: 0;
  text-transform: none;
}

/* ── 三级链接网格 ── */
.nav-group-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 2px;
}

/* ── 三级链接项 ── */
.nav-grid-link {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 12px;
  border-radius: 8px;
  color: rgba(226, 232, 240, 0.85);
  font-size: 14px;
  font-weight: 500;
  text-decoration: none;
  transition: background 0.15s ease, color 0.15s ease;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.nav-grid-link:hover {
  background: rgba(255, 255, 255, 0.07);
  color: #fff;
}

/* ── 国旗图标 ── */
.country-flag {
  width: 22px;
  height: 16px;
  flex-shrink: 0;
  object-fit: cover;
  border-radius: 3px;
  box-shadow: 0 1px 4px rgba(0, 0, 0, 0.4);
}

/* ── 纯二级：简单网格 ── */
.nav-simple-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 2px;
  padding: 4px 24px 8px;
}

.nav-simple-item {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 10px 12px;
  border-radius: 8px;
  color: rgba(226, 232, 240, 0.85);
  font-size: 14px;
  font-weight: 500;
  text-decoration: none;
  transition: background 0.15s ease, color 0.15s ease;
  background: transparent;
  border: none;
}

.nav-simple-item:hover {
  background: rgba(255, 255, 255, 0.07);
  color: #fff;
}

.nav-simple-icon {
  width: 24px;
  height: 24px;
  flex-shrink: 0;
}

.nav-simple-icon img {
  width: 100%;
  height: 100%;
  object-fit: contain;
}

.nav-simple-title {
  font-size: 14px;
  font-weight: 500;
  color: inherit;
}

.nav-simple-desc {
  font-size: 12px;
  color: rgba(148, 163, 184, 0.6);
  margin-top: 2px;
}

/* ── 空菜单 ── */
.nav-cont-menu.nav-cont-empty {
  display: none;
}

/* ── 响应式 ── */
@media (max-width: 768px) {
  .nav-cont {
    display: none !important;
  }

  .nav-group-grid {
    grid-template-columns: 1fr;
  }
}