/* ============================================
   杭州鼎腾实业有限公司 官网
   布局与导航栏样式
   ============================================ */

/* ========== 导航栏 ========== */

.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--nav-height);
    background: rgba(255, 255, 255, 0.9);
    backdrop-filter: blur(14px);
    border-bottom: 1px solid rgba(232, 230, 240, 0.6);
    box-shadow: 0 12px 30px rgba(39, 31, 63, 0.08);
    z-index: var(--z-fixed);
    transition: all var(--transition-normal);
}

.navbar-container {
    max-width: var(--container-max-width);
    margin: 0 auto;
    padding: 0 var(--container-padding);
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.navbar-brand {
    display: flex;
    align-items: center;
    gap: 0;
    text-decoration: none;
    color: var(--color-primary);
    font-weight: var(--font-weight-bold);
    font-size: 1.25rem;
    transition: color var(--transition-fast);
    white-space: nowrap;
}

.navbar-brand:hover {
    color: var(--color-primary-dark);
}

.navbar-brand-logo {
    width: 40px;
    height: 40px;
    background: var(--gradient-primary);
    border-radius: var(--border-radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-weight: var(--font-weight-bold);
    font-size: 1.25rem;
}

.navbar-menu {
    display: flex;
    list-style: none;
    gap: var(--spacing-lg);
    align-items: center;
    padding-top: 6px;
}

.navbar-item {
    position: relative;
}

.navbar-link {
    display: block;
    padding: var(--spacing-sm) 0;
    color: var(--color-text-dark);
    text-decoration: none;
    font-weight: var(--font-weight-medium);
    transition: color var(--transition-fast);
    position: relative;
}

.navbar-link:hover,
.navbar-link.active {
    color: var(--color-primary);
}

.navbar-link::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 0;
    width: 0;
    height: 2px;
    background-color: var(--color-accent);
    transition: width var(--transition-fast);
}

.navbar-link:hover::after,
.navbar-link.active::after {
    width: 100%;
}

/* ========== 下拉菜单 ========== */

.dropdown {
    position: relative;
}

.dropdown-menu {
    position: absolute;
    top: calc(100% + 8px);
    left: 0;
    background-color: var(--color-background);
    border: 1px solid var(--color-border-light);
    border-radius: var(--border-radius-md);
    box-shadow: var(--box-shadow-lg);
    min-width: 200px;
    list-style: none;
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px);
    transition: all var(--transition-normal);
    z-index: var(--z-dropdown);
}

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

.dropdown-item {
    display: block;
    padding: var(--spacing-sm) var(--spacing-md);
    color: var(--color-text-dark);
    text-decoration: none;
    transition: all var(--transition-fast);
    border-left: 3px solid transparent;
}

.dropdown-item:hover {
    background-color: var(--color-background-secondary);
    color: var(--color-primary);
    border-left-color: var(--color-accent);
    padding-left: calc(var(--spacing-md) + 4px);
}

.dropdown-item:first-child {
    border-radius: var(--border-radius-md) var(--border-radius-md) 0 0;
}

.dropdown-item:last-child {
    border-radius: 0 0 var(--border-radius-md) var(--border-radius-md);
}

/* ========== 页面内容区域 ========== */

main {
    margin-top: var(--nav-height);
    min-height: calc(100vh - var(--nav-height));
}

.page-section {
    padding: var(--spacing-3xl) var(--container-padding);
    position: relative;
    overflow: hidden;
}

.page-section.light {
    background-color: var(--color-background-secondary);
}

.page-section.dark {
    background-color: var(--color-background);
}

.page-section.gradient {
    background: var(--gradient-soft);
}

.section-title {
    text-align: center;
    margin-bottom: var(--spacing-2xl);
}

.section-title h2 {
    position: relative;
    display: inline-block;
}

.section-title h2::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 4px;
    background: var(--gradient-primary);
    border-radius: 2px;
}

.section-subtitle {
    text-align: center;
    color: var(--color-text-light);
    margin-top: var(--spacing-md);
}

/* ========== 页脚 ========== */

footer {
    background: linear-gradient(140deg, rgba(74, 15, 111, 0.95) 0%, rgba(106, 27, 154, 0.95) 45%, rgba(0, 172, 193, 0.85) 100%);
    color: white;
    padding: var(--spacing-3xl) var(--container-padding) var(--spacing-xl);
    margin-top: var(--spacing-3xl);
}

.footer-content {
    max-width: var(--container-max-width);
    margin: 0 auto;
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: var(--spacing-2xl);
    margin-bottom: var(--spacing-2xl);
}

.footer-section h4 {
    color: white;
    margin-bottom: var(--spacing-md);
}

.footer-section ul {
    list-style: none;
    margin: 0;
    padding: 0;
}

.footer-section li {
    margin-bottom: var(--spacing-sm);
}

.footer-section a {
    color: rgba(255, 255, 255, 0.8);
    transition: color var(--transition-fast);
}

.footer-section a:hover {
    color: var(--color-accent);
    text-decoration: none;
}

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.2);
    padding-top: var(--spacing-lg);
    text-align: center;
    color: rgba(255, 255, 255, 0.7);
    font-size: var(--font-size-sm);
}

.footer-bottom p {
    margin: 0;
}

/* ========== 面包屑导航 ========== */

.breadcrumb {
    display: flex;
    list-style: none;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-lg);
    padding: var(--spacing-md) 0;
    border-bottom: 1px solid var(--color-border-light);
}

.breadcrumb-item {
    color: var(--color-text-light);
}

.breadcrumb-item a {
    color: var(--color-primary);
}

.breadcrumb-item.active {
    color: var(--color-text-dark);
    font-weight: var(--font-weight-semibold);
}

.breadcrumb-item::after {
    content: '/';
    margin-left: var(--spacing-sm);
    color: var(--color-border);
}

.breadcrumb-item:last-child::after {
    content: '';
    margin-left: 0;
}

/* ========== 侧边栏 ========== */

.sidebar {
    background-color: var(--color-background-secondary);
    border-radius: var(--border-radius-lg);
    padding: var(--spacing-lg);
    box-shadow: var(--box-shadow-sm);
}

.sidebar-section {
    margin-bottom: var(--spacing-lg);
}

.sidebar-section:last-child {
    margin-bottom: 0;
}

.sidebar-title {
    font-size: var(--font-size-h5);
    font-weight: var(--font-weight-bold);
    margin-bottom: var(--spacing-md);
    color: var(--color-primary);
    border-bottom: 2px solid var(--color-accent);
    padding-bottom: var(--spacing-sm);
}

.sidebar-list {
    list-style: none;
    margin: 0;
    padding: 0;
}

.sidebar-list li {
    margin-bottom: var(--spacing-sm);
}

.sidebar-list a {
    display: block;
    padding: var(--spacing-sm);
    border-radius: var(--border-radius-md);
    transition: all var(--transition-fast);
}

.sidebar-list a:hover {
    background-color: var(--color-background);
    color: var(--color-accent);
    text-decoration: none;
    padding-left: calc(var(--spacing-sm) + 4px);
}

/* ========== 卡片 ========== */

.card {
    background-color: var(--color-background);
    border: 1px solid var(--color-border-light);
    border-radius: var(--border-radius-lg);
    overflow: hidden;
    transition: all var(--transition-normal);
    box-shadow: var(--box-shadow-sm);
}

.card:hover {
    box-shadow: var(--box-shadow-lg);
    transform: translateY(-4px);
}

.card-image {
    width: 100%;
    height: 200px;
    object-fit: cover;
    display: block;
}

.card-body {
    padding: var(--spacing-lg);
}

.card-title {
    font-size: var(--font-size-h4);
    font-weight: var(--font-weight-bold);
    margin-bottom: var(--spacing-md);
    color: var(--color-text-dark);
}

.card-text {
    color: var(--color-text-light);
    margin-bottom: var(--spacing-md);
    line-height: 1.8;
}

.card-footer {
    padding: var(--spacing-md) var(--spacing-lg);
    background-color: var(--color-background-secondary);
    border-top: 1px solid var(--color-border-light);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

/* ========== 响应式导航栏 ========== */

.navbar-toggle {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    color: var(--color-primary);
    font-size: 1.5rem;
}

@media (max-width: 768px) {
    .navbar-menu {
        position: fixed;
        top: var(--nav-height);
        left: -100%;
        flex-direction: column;
        background-color: var(--color-background);
        width: 100%;
        text-align: center;
        transition: 0.3s;
        box-shadow: var(--box-shadow-md);
        gap: 0;
        padding: var(--spacing-lg) 0;
    }

    .navbar-menu.active {
        left: 0;
    }

    .navbar-item {
        width: 100%;
    }

    .navbar-link {
        display: block;
        padding: var(--spacing-md);
        border-bottom: 1px solid var(--color-border-light);
    }

    .navbar-toggle {
        display: block;
    }

    .dropdown-menu {
        position: static;
        opacity: 0;
        visibility: hidden;
        transform: none;
        box-shadow: none;
        border: none;
        background-color: var(--color-background-secondary);
        max-height: 0;
        overflow: hidden;
        transition: max-height var(--transition-normal);
    }

    .dropdown:hover .dropdown-menu,
    .dropdown.active .dropdown-menu {
        opacity: 1;
        visibility: visible;
        max-height: 500px;
    }

    .footer-content {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 480px) {
    .footer-content {
        grid-template-columns: 1fr;
    }

    .page-section {
        padding: var(--spacing-xl) var(--container-padding);
    }
}