/* 滚动后调整body的padding-top */
        body.scrolled {
            padding-top: 60px; /* 原--navbar-scrolled-height */
        }

        /* 导航栏外层包裹section */
        section.index-navbar {
            position: fixed; /* 固定在顶部 */
            top: 0;
            left: 0;
            width: 100%;
            z-index: 999; /* 确保在最上层 */
            background: rgba(0, 0, 0, 0.8); /* 原--navbar-bg */
            box-shadow: 0 2px 10px rgba(0, 0, 0, 0.3);
            height: 80px; /* 原--navbar-height */
            transition: height 0.3s ease; /* 高度变化过渡 */
        }

        /* 滚动后导航栏高度变小 */
        section.index-navbar.scrolled {
            height: 60px; /* 原--navbar-scrolled-height */
            background: rgba(0, 0, 0, 0.9); /* 滚动后背景更不透明，增强视觉 */
        }

        /* 导航栏容器，居中限制宽度 */
        .navbar-container {
            max-width: 1600px;
            margin: 0 auto;
            display: flex;
            justify-content: space-between;
            align-items: center;
            height: 100%; /* 改为100%，继承父元素高度 */
            padding: 0 20px;
        }

        .navbar-logo {
            display: block;
            width: 150px; 
            transition: all 0.3s ease; 
        }

        /* 滚动后Logo变小 */
        .index-navbar.scrolled .navbar-logo {
            width: 100px;  
        }

        .navbar-logo img {
            width: 100%;
            height: 100%;
            object-fit: contain; /* 保持图片比例，不拉伸 */
        }

        /* 主导航菜单 */
        .navbar-menu {
            display: flex;
            align-items: center;
        }

        /* 导航菜单项 */
        .menu-item {
            position: relative; /* 为二级菜单定位做准备 */
            margin: 0 15px;
        }

        .menu-item > a {
            display: block;
            color: #fff; /* 原--text-color */
            font-size: 16px;
            padding: 10px 15px;
            transition: all 0.3s ease;
            position: relative; /* 为下划线伪元素定位 */
        }

        /* 主导航项悬浮：底部出现下划线 */
        .menu-item > a::after {
            content: "";
            position: absolute;
            bottom: 0;
            left: 0;
            width: 0;
            height: 2px;
            background-color: #39FF14; /* 原--highlight-color */
            transition: width 0.3s ease;
        }

        .menu-item > a:hover::after {
            width: 100%;
        }

        .menu-item > a:hover {
            color: #39FF14; 
            background: transparent; 
        }

     
        .submenu {
    position: fixed;
    left: 50%;
    top:  50px;
    transform: translateX(-50%) translateY(10px);
    background: rgba(0, 0, 0, 0.95);
    border-radius: 4px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.5);
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
    padding: 15px;
    display: flex; 
    gap: 15px; 
    width: auto;
    min-width: 1200px; 
    z-index: 1000; 
    flex-wrap: wrap;
}

 
.index-navbar.scrolled ~ .submenu {
    top: 80px;  
}

 
.menu-item.has-submenu:hover .submenu {
    opacity: 1;
    visibility: visible;
    transform: translateX(-50%) translateY(0);  
} 

 
        .submenu-item {
            flex: 0 0 calc(20% - 12px); 
            text-align: center;
        }

        .submenu-item a {
            display: flex;
            flex-direction: column;  
            align-items: center;
            color: #fff;  
            padding: 10px;
            border-radius: 4px;
            transition: background 0.3s ease;
            position: relative;  
        }

        /* 二级菜单项悬浮下划线 */
        .submenu-item a::after {
            content: "";
            position: absolute;
            bottom: 0;
            left: 0;
            width: 0;
            height: 2px;
            background-color: #39FF14;  
            transition: width 0.3s ease;
        }

        .submenu-item a:hover::after {
            width: 100%;  
        }

        .submenu-item a:hover {
            background: rgba(57, 255, 20, 0.2); 
            color: #39FF14; 
        }
 
        .submenu-img {
            width: 100%;   
            border-radius: 0;  
            margin-bottom: 8px;  
            object-fit: cover;
            border: 2px solid transparent;
            transition: border-color 0.3s ease;
        }

        .submenu-item a:hover .submenu-img {
            border-color: #39FF14;  
        }

        /* 二级菜单标题 */
        .submenu-title {
            font-size: 14px;
            transition: color 0.3s ease;
            white-space: nowrap; /* 标题不换行 */
        }

        .submenu-item a:hover .submenu-title {
            color: #39FF14; /* 原--highlight-color */
        }

        /* 搜索+语言切换容器 */
        .navbar-actions {
            display: flex;
            align-items: center;
            gap: 20px;
        }

        /* 搜索框样式 */
        .search-box {
            position: relative;
        }

        .search-input {
            height: 40px;
            width: 200px;
            padding: 0 15px 0 40px;
            border: 1px solid rgba(255, 255, 255, 0.2);
            background: rgba(0, 0, 0, 0.1);
            color: #fff; /* 原--text-color */
            border-radius: 20px;
            outline: none;
            transition: all 0.3s ease;
        }

        .search-input:focus {
            border-color: #39FF14; /* 原--highlight-color */
            background: rgba(0, 0, 0, 0.15);
            width: 250px;
        }

        /* 搜索图标伪元素 */
        .search-box::before {
            content: "🔍";
            position: absolute;
            left: 15px;
            top: 50%;
            transform: translateY(-50%);
            color: #fff; /* 原--text-color */
            font-size: 16px;
        }



        /* 汉堡菜单（移动端） */
        .hamburger {
            display: none;
            flex-direction: column;
            gap: 4px;
            cursor: pointer;
        }

        .hamburger-line {
            width: 25px;
            height: 3px;
            background: #fff; /* 原--text-color */
            border-radius: 2px;
            transition: all 0.3s ease;
        }

        .hamburger:hover .hamburger-line {
            background: #39FF14; /* 原--highlight-color */
        }

        /* 媒体查询：适配移动端（768px以下） */
        @media (max-width: 768px) {
            /* 隐藏PC端菜单和操作区 */
            .navbar-menu,
            .navbar-actions {
                display: none;
            }

            /* 显示汉堡菜单 */
            .hamburger {
                display: flex;
            }

            /* 移动端展开菜单样式 */
            .navbar-container.active .navbar-menu {
                display: flex;
                flex-direction: column;
                position: absolute;
                top: 80px; /* 原--navbar-height */
                left: 0;
                width: 100%;
                background: rgba(0, 0, 0, 0.95);
                padding: 20px 0;
                transition: top 0.3s ease; /* 配合导航栏高度变化 */
            }

            /* 滚动后调整移动端展开菜单的top值 */
            .index-navbar.scrolled .navbar-container.active .navbar-menu {
                top: 60px; /* 原--navbar-scrolled-height */
            }

            .navbar-container.active .navbar-actions {
                display: flex;
                flex-direction: column;
                position: absolute;
                top: calc(80px + 300px); /* 原--navbar-height + 300px */
                left: 0;
                width: 100%;
                background: rgba(0, 0, 0, 0.95);
                padding: 20px;
                gap: 15px;
                transition: top 0.3s ease; /* 配合导航栏高度变化 */
            }

            /* 滚动后调整移动端操作区的top值 */
            .index-navbar.scrolled .navbar-container.active .navbar-actions {
                top: calc(60px + 300px); /* 原--navbar-scrolled-height + 300px */
            }

            /* 移动端二级菜单调整为竖向排列 */
            .submenu {
                flex-direction: column;
                width: 200px;
                min-width: auto;
                gap: 5px;
            }

            .submenu-item {
                flex: none;
                width: 100%;
            }
 

            .menu-item {
                margin: 10px 0;
            }

            .search-input {
                width: 100%;
            }

            .search-input:focus {
                width: 100%;
            }
        }