/* 公共头部样式 - 提取自 index.css, about_us.css 等 */

/* 顶部导航栏 */
.header {
    background: #fff;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    padding: 15px 0;
    width: 100%;
    margin: 0;
}

.header-container {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 20px;
    width: 100%;
    box-sizing: border-box; /* 确保padding不会撑大宽度 */
}

/* Logo容器 */
.logo-container {
    display: flex;
    align-items: center;
    gap: 12px;
}

/* Logo图标 */
.logo-icon {
    width: 20px;
    height: 20px;
    object-fit: contain;
    transition: transform 0.3s ease;
}

.logo-icon:hover {
    transform: scale(1.1);
}

img.logo {
    font-size: 24px;
    font-weight: bold;
    color: #1a73e8;
    text-decoration: none;
    max-width: 350px; /* 统一设置最大宽度 */
    min-width: 250px;
    height: auto;
    object-fit: contain;
}

.nav-menu {
    display: flex;
    list-style: none;
    margin: 0;
    padding: 0;
    gap: 30px;
    align-items: center;
}

.nav-menu li a {
    text-decoration: none;
    color: #333;
    font-weight: 600;
    font-size: 16px;
    transition: all 0.3s ease;
    padding: 10px 20px;
    border-radius: 6px;
    position: relative;
}

.nav-menu li a:hover {
    color: #1a73e8;
    background: #e8f0fe;
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(26, 115, 232, 0.15);
}

.nav-menu li a.active {
    color: #1a73e8;
    background: #e8f0fe;
    font-weight: 700;
}

/* 下拉菜单样式 */
.dropdown {
    position: relative;
}

.dropdown-toggle {
    position: relative;
    padding: 10px 30px 10px 20px !important; /* 增加右侧内边距，给箭头留出空间 */
    cursor: pointer;
}

.dropdown-toggle::after {
    content: '';
    position: absolute;
    right: 10px; /* 调整右侧位置 */
    top: 50%;
    margin-top: 2px; /* 微调垂直位置 */
    transform: translateY(-50%);
    border-left: 5px solid transparent;
    border-right: 5px solid transparent;
    border-top: 5px solid #666;
    transition: transform 0.3s ease;
}

.dropdown:hover .dropdown-toggle::after {
    transform: translateY(-50%) rotate(180deg);
}

/* 移除原有的伪元素样式，避免冲突 */
.nav-menu li a::after {
    display: none;
}


.dropdown-menu {
    position: absolute;
    top: 100%;
    left: 50%;
    transform: translateX(-50%);
    background: #fff;
    min-width: 200px;
    box-shadow: 0 4px 20px rgba(0,0,0,0.1);
    border-radius: 8px;
    padding: 8px 0;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    z-index: 1001;
    border: 1px solid #e0e0e0;
    margin-top: 0; /* 移除可能的 margin-top */
}

/* 增加透明伪元素填充间隙，防止鼠标移出 */
.dropdown-menu::before {
    content: '';
    position: absolute;
    top: -10px; /* 向上延伸，覆盖间隙 */
    left: 0;
    width: 100%;
    height: 10px;
    background: transparent;
}

.dropdown:hover .dropdown-menu {
    opacity: 1;
    visibility: visible;
    transform: translateX(-50%);
    top: 100%; /* 确保紧贴父元素底部 */
}

.dropdown-submenu {
    position: relative;
}

.dropdown-submenu > a {
    display: block;
    padding: 10px 20px;
    color: #333;
    text-decoration: none;
    transition: all 0.2s ease;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.dropdown-submenu > a:hover {
    background: #f8f9fa;
    color: #1a73e8;
    padding-left: 25px;
}

.dropdown-submenu > a::after {
    content: '›';
    font-size: 18px;
    line-height: 1;
    margin-left: 10px;
    transition: transform 0.3s ease;
}

.dropdown-submenu:hover > a::after {
    transform: translateX(3px);
}

.submenu {
    position: absolute;
    top: 0;
    left: 100%;
    margin-left: 0; /* 移除 margin-left */
    background: #fff;
    min-width: 180px;
    box-shadow: 0 4px 20px rgba(0,0,0,0.1);
    border-radius: 8px;
    padding: 8px 0;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    border: 1px solid #e0e0e0;
}

/* 增加透明伪元素填充子菜单间隙 */
.submenu::before {
    content: '';
    position: absolute;
    top: 0;
    left: -10px; /* 向左延伸，覆盖间隙 */
    width: 10px;
    height: 100%;
    background: transparent;
}

.dropdown-submenu:hover .submenu {
    opacity: 1;
    visibility: visible;
    transform: translateX(0);
}

.submenu li a {
    display: block;
    padding: 10px 20px;
    color: #666;
    text-decoration: none;
    transition: all 0.2s ease;
    font-size: 14px;
    position: relative;
}

.submenu a:hover {
    background: linear-gradient(135deg, #f8f9fa 0%, #e8f0fe 100%);
    color: #1a73e8;
    padding-left: 25px;
}

.submenu a:hover::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 3px;
    background: #1a73e8;
    border-radius: 0 2px 2px 0;
}

/* 汉堡菜单按钮 - 默认隐藏 */
    .mobile-menu-toggle {
        display: none;
    }

    /* 响应式设计 - 移动设备适配 (从 page_public.css 中提取并整合) */
    @media (max-width: 768px) {
    /* 强制头部单行显示 */
    .header {
        height: 120px; /* 固定头部高度 */
        padding: 0 15px !important;
        display: flex;
        align-items: center;
        overflow: visible; /* 允许菜单溢出显示 */
        position: fixed !important; /* 强制固定定位 */
        top: 0 !important;
        left: 0 !important;
        right: 0 !important;
        z-index: 1000 !important;
        background-color: #fff !important;
        box-shadow: 0 2px 4px rgba(0,0,0,0.05) !important;
    }

    /* 占位元素，防止内容被固定头部遮挡 - 注意：这通常需要放在 body 上，这里作为提示 */
    /* body { padding-top: 60px; } */

    .header-container {
        flex-direction: row;
        align-items: center;
        justify-content: space-between;
        padding: 0 !important;
        position: relative;
        width: 100%;
        height: 100%;
        margin: 0 !important;
    }
    
    .logo-container {
        margin-bottom: 0 !important;
        height: 100%;
        display: flex;
        align-items: center;
    }
    
    img.logo, .logo {
        min-width: 500px !important;
        width: auto !important;
        height: auto !important;
    }


        /* 汉堡菜单按钮 */
        .mobile-menu-toggle {
            display: block !important;
            background: none !important;
            border: none !important;
            font-size: 24px !important;
            color: #333 !important;
            cursor: pointer !important;
            padding: 10px !important;
            line-height: 1 !important;
            position: absolute !important;
            right: 0 !important;
            top: 50% !important;
            transform: translateY(-50%) !important;
            margin: 0 !important;
            z-index: 1002 !important;
        }
    
    /* 确保 nav 标签不影响布局 */
    nav {
        display: contents;
    }

    /* 移动端菜单样式 */
    .nav-menu {
        flex-direction: column !important;
        width: 100% !important;
        gap: 0 !important;
        margin-top: 0 !important;
        display: none !important; /* 默认隐藏 */
        position: absolute !important;
        top: 120px !important; /* 紧贴 Header 底部 */
        left: -15px !important; /* 抵消 header padding */
        right: -15px !important; /* 抵消 header padding */
        width: calc(100% + 30px) !important;
        background: #fff !important;
        box-shadow: 0 4px 6px rgba(0,0,0,0.1) !important;
        padding: 0 !important;
        z-index: 1001 !important;
    }
    
    .nav-menu.active {
        display: flex !important; /* 激活时显示 */
    }

    .nav-menu li {
        width: 100% !important;
        border-bottom: 1px solid #f0f0f0 !important;
        display: block !important;
    }

    .nav-menu li:last-child {
        border-bottom: none !important;
    }

    .nav-menu li a {
        display: block !important;
        padding: 15px 20px !important;
        font-size: 16px !important;
        text-align: left !important;
    }
    
    /* 移动端下拉菜单优化 */
    .dropdown-menu {
        position: static;
        opacity: 1;
        visibility: visible;
        transform: none;
        box-shadow: none;
        border: 1px solid #e0e0e0;
        margin-top: 5px;
        display: none;
        width: 100%;
        padding-left: 20px; /* 增加层级感 */
    }
    
    .dropdown.active .dropdown-menu {
        display: block;
    }
    
    .submenu {
        position: static;
        opacity: 1;
        visibility: visible;
        transform: none;
        box-shadow: none;
        border-left: 3px solid #e0e0e0;
        margin-left: 20px;
        display: none;
        width: calc(100% - 20px);
    }
    
    .dropdown-submenu.active .submenu {
        display: block;
    }
    
    .dropdown-toggle::after {
        content: '▼';
    }
    
    .dropdown-submenu > a::after {
        content: '▶';
    }
}

/* Logo文字样式 */
.logo-link {
    display: flex;
    align-items: center;
    text-decoration: none !important;
}

.logo-text {
    font-size: 22px;
    font-weight: 800;
    color: #1a73e8;
    margin-left: 10px;
    white-space: nowrap;
    letter-spacing: 0.5px;
}

@media (max-width: 768px) {
    .logo-text {
        display: block; /* 移动端显示文字 */
        font-size: 16px; /* 减小字体大小 */
        margin-left: 6px;
    }
    
    img.logo {
        max-width: 80px !important; /* 稍微减小 Logo 图片大小 */
    }
}