/* 导航栏样式 */
.custom-nav {
    background-color: var(--wuda-blue);
    color: var(--text-light);
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    box-shadow: var(--shadow-md);
    transition: background-color var(--transition-normal), box-shadow var(--transition-normal);
    height: 60px;
}

/* 全局页面内容顶部边距，避免被固定导航栏遮挡 */
body {
    margin-top: 60px;
}

.custom-nav.scrolled {
    background-color: rgba(0, 51, 102, 0.95);
    box-shadow: var(--shadow-lg);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 100%;
}

.nav-brand {
    font-size: 1.5rem;
    font-weight: bold;
    color: var(--text-light);
    text-decoration: none;
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    transition: transform var(--transition-fast);
}

.nav-brand:hover {
    transform: scale(1.05);
}

/* 移动端菜单按钮 */
.mobile-menu-btn {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    padding: var(--spacing-sm);
    z-index: 1001;
}

.menu-icon {
    display: block;
    width: 24px;
    height: 2px;
    background-color: var(--text-light);
    margin: 5px 0;
    transition: all var(--transition-normal);
}

.mobile-menu-btn.active .menu-icon:nth-child(1) {
    transform: rotate(45deg) translate(5px, 5px);
}

.mobile-menu-btn.active .menu-icon:nth-child(2) {
    opacity: 0;
}

.mobile-menu-btn.active .menu-icon:nth-child(3) {
    transform: rotate(-45deg) translate(7px, -6px);
}

/* 导航链接 */
.nav-links {
    display: flex;
    gap: var(--spacing-md);
    align-items: center;
    transition: all var(--transition-normal);
}

.nav-link {
    color: var(--text-light);
    text-decoration: none;
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--radius-sm);
    transition: all var(--transition-fast);
    position: relative;
}

.nav-link:hover {
    background-color: rgba(255, 255, 255, 0.1);
    transform: translateY(-2px);
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    width: 0;
    height: 2px;
    background-color: var(--gold);
    transition: all var(--transition-fast);
    transform: translateX(-50%);
}

.nav-link:hover::after {
    width: 80%;
}

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

.dropdown-menu {
    position: absolute;
    top: 100%;
    left: 0;
    background-color: var(--wuda-blue);
    border-radius: var(--radius-sm);
    box-shadow: var(--shadow-lg);
    display: none;
    min-width: 200px;
    z-index: 1000;
    margin-top: var(--spacing-xs);
    opacity: 0;
    transform: translateY(-10px);
    transition: all var(--transition-normal);
}

.nav-dropdown:hover .dropdown-menu,
.dropdown-menu.active {
    display: block;
    opacity: 1;
    transform: translateY(0);
}

.dropdown-item {
    display: block;
    color: var(--text-light);
    text-decoration: none;
    padding: var(--spacing-sm) var(--spacing-md);
    transition: all var(--transition-fast);
    border-radius: var(--radius-sm);
}

.dropdown-item:hover {
    background-color: rgba(255, 255, 255, 0.1);
    padding-left: calc(var(--spacing-md) + var(--spacing-xs));
}

/* 移动端菜单覆盖层 */
.mobile-menu-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: rgba(0, 0, 0, 0.5);
    z-index: 999;
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-normal);
}

.mobile-menu-overlay.active {
    opacity: 1;
    visibility: visible;
}

/* 媒体查询 - 移动端 */
@media (max-width: 992px) {
    .mobile-menu-btn {
        display: block;
    }
    
    .nav-links {
        position: fixed;
        top: 60px;
        right: -300px;
        width: 280px;
        height: calc(100vh - 60px);
        background-color: var(--wuda-blue);
        flex-direction: column;
        align-items: flex-start;
        padding: 20px;
        gap: 8px;
        box-shadow: -5px 0 15px rgba(0, 0, 0, 0.2);
        z-index: 1000;
    }
    
    .nav-links.active {
        right: 0;
    }
    
    .nav-link {
        width: 100%;
        padding: 12px 16px;
        font-size: 16px;
        line-height: 1.4;
    }
    
    .nav-dropdown {
        width: 100%;
    }
    
    .dropdown-menu {
        position: static;
        min-width: 100%;
        box-shadow: none;
        margin-top: 4px;
        background-color: rgba(0, 0, 0, 0.2);
    }
    
    .dropdown-item {
        padding: 10px 20px;
        font-size: 14px;
        line-height: 1.3;
    }
    
    body.menu-open {
        overflow: hidden;
    }
}

/* 媒体查询 - 小屏移动端 */
@media (max-width: 480px) {
    .nav-links {
        width: 240px;
        padding: 16px;
    }
    
    .nav-link {
        padding: 10px 14px;
        font-size: 15px;
    }
    
    .dropdown-item {
        padding: 8px 16px;
        font-size: 13px;
    }
    
    .nav-brand {
        font-size: 1.2rem;
    }
}

/* 容器样式 */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

/* 网格系统 */
.row {
    display: flex;
    flex-wrap: wrap;
    margin: 0 calc(-1 * var(--spacing-sm));
}

.col-md {
    flex: 1;
    padding: 0 var(--spacing-sm);
}

.col-md-2 {
    flex: 0 0 16.666667%;
    max-width: 16.666667%;
    padding: 0 var(--spacing-sm);
}

.col-md-3 {
    flex: 0 0 25%;
    max-width: 25%;
    padding: 0 var(--spacing-sm);
}

.col-md-4 {
    flex: 0 0 33.333333%;
    max-width: 33.333333%;
    padding: 0 var(--spacing-sm);
}

.col-md-5 {
    flex: 0 0 41.666667%;
    max-width: 41.666667%;
    padding: 0 var(--spacing-sm);
}

.col-md-6 {
    flex: 0 0 50%;
    max-width: 50%;
    padding: 0 var(--spacing-sm);
}

.col-md-8 {
    flex: 0 0 66.666667%;
    max-width: 66.666667%;
    padding: 0 var(--spacing-sm);
}

.col-md-12 {
    flex: 0 0 100%;
    max-width: 100%;
    padding: 0 var(--spacing-sm);
}

.col-lg-3 {
    flex: 0 0 25%;
    max-width: 25%;
    padding: 0 var(--spacing-sm);
}

/* 间距工具类 */
.mt-2 {
    margin-top: var(--spacing-sm) !important;
}

.mt-4 {
    margin-top: var(--spacing-lg) !important;
}

.mt-5 {
    margin-top: var(--spacing-xxl) !important;
}

.mt-20 {
    margin-top: 10rem !important;
}

.mb-3 {
    margin-bottom: var(--spacing-md) !important;
}

.mb-4 {
    margin-bottom: var(--spacing-lg) !important;
}

.mb-5 {
    margin-bottom: var(--spacing-xxl) !important;
}

.my-4 {
    margin-top: var(--spacing-lg) !important;
    margin-bottom: var(--spacing-lg) !important;
}

/* 文本对齐工具类 */
.text-center {
    text-align: center !important;
}

.text-sm-start {
    text-align: left !important;
}

.text-end {
    text-align: right !important;
}

/* 文本颜色工具类 */
.text-light {
    color: var(--text-light) !important;
}

.text-dark {
    color: var(--text-dark) !important;
}

.text-warning {
    color: var(--gold) !important;
}

.text-muted {
    color: var(--text-muted) !important;
}

.text-primary {
    color: var(--wuda-blue) !important;
}

/* 背景颜色工具类 */
.bg-dark {
    background-color: var(--dark) !important;
    color: var(--text-light) !important;
}

.bg-dark h1, .bg-dark h2, .bg-dark h3, .bg-dark h4, .bg-dark h5, .bg-dark h6 {
    color: var(--text-light) !important;
}

.bg-dark p {
    color: rgba(255, 255, 255, 0.9) !important;
    line-height: 1.7;
}

.bg-dark .lead {
    color: rgba(255, 255, 255, 0.95) !important;
}

.bg-light {
    background-color: var(--light) !important;
}

.bg-info {
    background-color: #17a2b8 !important;
}

.bg-secondary {
    background-color: var(--gray) !important;
}

/* 弹性布局工具类 */
.d-flex {
    display: flex !important;
}

.flex-column {
    flex-direction: column !important;
}

.align-items-center {
    align-items: center !important;
}

.align-items-end {
    align-items: flex-end !important;
}

.justify-content-center {
    justify-content: center !important;
}

.justify-content-between {
    justify-content: space-between !important;
}

/* 宽度工具类 */
.w-25 {
    width: 25% !important;
}

.w-50 {
    width: 50% !important;
}

.w-100 {
    width: 100% !important;
}

/* 圆角工具类 */
.rounded {
    border-radius: var(--radius-md) !important;
}

.rounded-circle {
    border-radius: var(--radius-full) !important;
}

/* 阴影工具类 */
.shadow-lg {
    box-shadow: var(--shadow-lg) !important;
}

/* 显示/隐藏工具类 */
.d-none {
    display: none !important;
}

.d-md-block {
    display: block !important;
}

/* 实用工具类 */
.p-5 {
    padding: var(--spacing-xxl) !important;
}

.pt-20 {
    padding-top: 2rem !important;
}

/* 页脚样式 */
footer {
    background-color: var(--wuda-blue);
    color: var(--text-light);
    padding: var(--spacing-xxl) 0;
    position: relative;
    overflow: hidden;
}

footer::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--wuda-blue), var(--wuda-red), var(--wuda-blue));
}

footer .container {
    position: relative;
    z-index: 1;
}

footer p {
    margin: 0;
    font-size: 0.875rem;
    opacity: 0.8;
}