/* ===================================
   网站页脚样式
   =================================== */

/* 页脚主容器 */
.site-footer {
    background-color: #f8f9fa;
    border-top: 1px solid #e9ecef;
    padding: 60px 0 20px;
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
}

/* 页脚容器 */
.footer-container {
    max-width: 1320px;
    margin: 0 auto;
    padding: 0 20px;
}

/* 页脚主要内容区域 */
.footer-main {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 40px;
    gap: 100px;
}

/* 左侧Logo区域 */
.footer-logo {
    flex: 0 0 auto;
    min-width: 200px;
}

.footer-logo-img {
    height: 50px;
    width: auto;
    max-width: 200px;
    object-fit: contain;
}

/* 右侧导航链接区域 */
.footer-nav {
    flex: 1;
    display: flex;
    gap: 4rem;
    justify-content: space-between;
}

/* 导航列 */
.footer-nav-column {
    flex: 0 1 auto;
    min-width: 0;
    text-align: center;
}

/* 导航标题 */
.footer-nav-title {
    font-size: 16px;
    font-weight: 600;
    color: #333;
    margin: 0 0 20px 0;
    padding-bottom: 8px;
    border-bottom: 2px solid #1369a8;
    display: inline-block;
    min-width: 80px;
}

/* 导航列表 */
.footer-nav-list {
    list-style: none;
    margin: 0;
    padding: 0;
}

.footer-nav-list li {
    margin-bottom: 12px;
}

.footer-nav-list li:last-child {
    margin-bottom: 0;
}

/* 导航链接 */
.footer-nav-list a {
    color: #333;
    text-decoration: none;
    font-size: 14px;
    line-height: 1.5;
    transition: color 0.3s ease;
    display: block;
    padding: 2px 0;
}

.footer-nav-list a:hover {
    color: #295ca8;
    text-decoration: none;
}

/* 页脚底部 */
.footer-bottom {
    border-top: 1px solid #e9ecef;
    padding-top: 20px;
    text-align: center;
}

/* 版权信息 */
.footer-copyright {
    margin: 0;
}

.footer-copyright p {
    color: #999;
    font-size: 13px;
    line-height: 1.5;
    margin: 0;
}

.footer-copyright a {
    color: #999;
    text-decoration: none;
    transition: color 0.3s ease;
}

.footer-copyright a:hover {
    color: #1369a8;
    text-decoration: underline;
}

/* 滚动进度指示器 */
.scroll-indicator {
    position: fixed;
    top: 0;
    left: 0;
    width: 0%;
    height: 3px;
    background: linear-gradient(90deg, #1369a8, #0c947b);
    z-index: 9999;
    transition: width 0.1s ease;
}

/* 回到顶部按钮 */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    background: #1369a8;
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    text-decoration: none;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
    z-index: 1000;
    box-shadow: 0 4px 12px rgba(19, 105, 168, 0.3);
}

.back-to-top:hover {
    background: #0f5a94;
    transform: translateY(-2px);
    box-shadow: 0 6px 16px rgba(19, 105, 168, 0.4);
    color: white;
    text-decoration: none;
}

.back-to-top.show {
    opacity: 1;
    visibility: visible;
}

.back-to-top i {
    font-size: 18px;
}

/* ===================================
   响应式设计
   =================================== */

/* 平板设备 */
@media (max-width: 1024px) {
    .footer-main {
        gap: 40px;
    }
    
    .footer-nav {
        gap: 30px;
    }
    
    .footer-logo {
        min-width: 160px;
    }
    
    .footer-logo-img {
        height: 45px;
        max-width: 160px;
    }
}

/* 小平板设备 */
@media (max-width: 768px) {
    .site-footer {
        padding: 40px 0 20px;
        margin-top: 80px;
    }
    
    .footer-main {
        flex-direction: column;
        gap: 40px;
        text-align: center;
        align-items: center;
    }
    
    .footer-logo {
        min-width: auto;
        align-self: center;
    }
    
    .footer-nav {
        width: 100%;
        flex-wrap: wrap;
        justify-content: center;
        gap: 30px 40px;
        text-align: center;
    }
    
    .footer-nav-column {
        flex: 0 0 calc(50% - 20px);
        min-width: 140px;
        text-align: center;
    }
    
    .footer-nav-title {
        text-align: center;
    }
    
    .back-to-top {
        bottom: 20px;
        right: 20px;
        width: 45px;
        height: 45px;
    }
    
    .back-to-top i {
        font-size: 16px;
    }
}

/* 手机设备 */
@media (max-width: 480px) {
    .site-footer {
        padding: 30px 0 15px;
        margin-top: 80px;
    }
    
    .footer-container {
        padding: 0 15px;
    }
    
    .footer-main {
        gap: 30px;
        margin-top: 3rem;
    }
    
    .footer-nav {
        flex-direction: column;
        gap: 25px;
        align-items: center;
    }
    
    .footer-nav-column {
        flex: none;
        width: 100%;
        max-width: 200px;
    }
    
    .footer-logo-img {
        height: 40px;
        max-width: 140px;
    }
    
    .footer-nav-title {
        font-size: 15px;
        margin-bottom: 15px;
    }
    
    .footer-nav-list a {
        font-size: 13px;
    }
    
    .footer-nav-list li {
        margin-bottom: 10px;
    }
    
    .footer-copyright p {
        font-size: 12px;
        line-height: 1.6;
    }
    
    .back-to-top {
        bottom: 15px;
        right: 15px;
        width: 40px;
        height: 40px;
    }
    
    .back-to-top i {
        font-size: 14px;
    }
}

/* 超小屏幕设备 */
@media (max-width: 360px) {
    .footer-container {
        padding: 0 10px;
    }
    
    .footer-nav-column {
        max-width: 180px;
    }
    
    .footer-copyright p {
        font-size: 11px;
    }
}

/* ===================================
   打印样式
   =================================== */
@media print {
    .site-footer {
        background: white !important;
        border-top: 1px solid #ccc !important;
        margin-top: 20px !important;
        padding: 20px 0 !important;
    }
    
    .scroll-indicator,
    .back-to-top {
        display: none !important;
    }
    
    .footer-nav-list a {
        color: #333 !important;
    }
    
    .footer-copyright a {
        color: #666 !important;
    }
}

/* ===================================
   无障碍访问优化
   =================================== */
@media (prefers-reduced-motion: reduce) {
    .footer-nav-list a,
    .footer-copyright a,
    .back-to-top,
    .scroll-indicator {
        transition: none;
    }
}

/* 高对比度模式 */
@media (prefers-contrast: high) {
    .site-footer {
        background-color: white;
        border-top: 2px solid #000;
    }
    
    .footer-nav-title {
        color: #000;
        border-bottom-color: #000;
    }
    
    .footer-nav-list a {
        color: #000;
    }
    
    .footer-nav-list a:hover {
        color: #000;
        background-color: #ffff00;
    }
    
    .footer-copyright p,
    .footer-copyright a {
        color: #000;
    }
}