/* ===== 顶部导航栏：深红→浅红→浅蓝→深蓝渐变 ===== */
        .navbar.navbar-inverse.navbar-fixed-top {
            background: linear-gradient(90deg, #8B0000 0%, #C8102E 25%, #4a7fc1 70%, #003366 100%) !important;
            border: none !important;
            box-shadow: 0 2px 12px rgba(0,0,0,0.35);
            min-height: 64px;
            padding: 0 2rem !important; 
            display: flex;
            align-items: center;}
        .navbar.navbar-inverse .navbar-brand,
        .navbar.navbar-inverse .navbar-nav > li > a {
            color: #fff !important;
            font-family: 'Noto Sans SC', 'Microsoft YaHei', sans-serif;
            font-size: 14px;
            letter-spacing: 0.04em;}
        .navbar.navbar-inverse .navbar-nav > li > a:hover,
        .navbar.navbar-inverse .navbar-nav > li > a:focus {
            color: #ffe0e0 !important;
            background: rgba(255,255,255,0.12) !important;}
        .navbar.navbar-inverse .navbar-nav > li.active > a {
            background: rgba(255,255,255,0.18) !important;
            color: #fff !important;}
        /* 下拉菜单 */
        .navbar.navbar-inverse .dropdown-menu {
            background: linear-gradient(135deg, #C8102E 0%, #003366 100%);
            border: none;
            border-radius: 0 0 6px 6px;
            box-shadow: 0 6px 20px rgba(0,0,0,0.25);
            min-width: 160px;}
        .navbar.navbar-inverse .dropdown-menu > li > a {
            color: #fff !important;
            font-size: 13px;
            padding: 9px 18px;
            transition: background 0.2s;}
        .navbar.navbar-inverse .dropdown-menu > li > a:hover {
            background: rgba(255,255,255,0.18) !important;
            color: #ffe0e0 !important;}
        .navbar.navbar-inverse .navbar-toggle .icon-bar { background: #fff;}
        .navbar.navbar-inverse .navbar-toggle { border-color: rgba(255,255,255,0.4);}

        /* ===== Header 轮播区 ===== */
        header#head {
            margin-top: 64px;
            position: relative;
            width: 100%;
            min-height: 480px;
            background-size: cover !important;
            background-position: center !important;
            overflow: hidden;}
        header#head::after {
            content: '';
            position: absolute;
            bottom: 0; left: 0; right: 0;
            height: 80px;
            background: linear-gradient(to top, rgba(0,0,0,0.45), transparent);
            pointer-events: none;}
        header#head .container { position: relative; z-index: 2;}
        #bgnav { text-align: center;}
        #bgnav img { max-width: 100%; border-radius: 4px; box-shadow: 0 4px 24px rgba(0,0,0,0.3);}