/* ===== 全局样式 ===== */
:root {
    --primary-color: #1890ff;
    --text-color: #333;
    --text-secondary: #666;
    --text-light: #999;
    --border-color: #e5e5e5;
    --bg-color: #f5f5f5;
    --white: #fff;
    --shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
    --radius: 8px;
}

body {
    background-color: var(--bg-color);
    min-height: 100vh;
}

/* ===== PC端顶部导航 ===== */
.nav-header {
    background: var(--white);
    box-shadow: var(--shadow);
    position: sticky;
    top: 0;
    z-index: 100;
    display: block;
}

.nav-header .container {
    display: flex;
    align-items: center;
    height: 60px;
    max-width: 1200px;
}

.nav-logo a {
    font-size: 1.5rem;
    font-weight: bold;
    color: var(--primary-color);
}

.nav-menu {
    display: flex;
    margin-left: 40px;
}

.nav-menu a {
    padding: 0 20px;
    height: 60px;
    line-height: 60px;
    color: var(--text-color);
    transition: color 0.3s;
}

.nav-menu a:hover,
.nav-menu a.active {
    color: var(--primary-color);
}

.nav-search {
    margin-left: auto;
}

.nav-search form {
    display: flex;
}

.nav-search input {
    width: 200px;
    height: 36px;
    padding: 0 12px;
    border: 1px solid var(--border-color);
    border-radius: var(--radius) 0 0 var(--radius);
    outline: none;
    transition: border-color 0.3s;
}

.nav-search input:focus {
    border-color: var(--primary-color);
}

.nav-search button {
    width: 60px;
    height: 36px;
    background: var(--primary-color);
    color: var(--white);
    border-radius: 0 var(--radius) var(--radius) 0;
    transition: background 0.3s;
}

.nav-search button:hover {
    background: #40a9ff;
}

/* ===== 移动端顶部导航 ===== */
.mobile-header {
    display: none;
    background: var(--white);
    box-shadow: var(--shadow);
    position: sticky;
    top: 0;
    z-index: 100;
    padding: 10px 15px;
}

.mobile-logo a {
    font-size: 1.2rem;
    font-weight: bold;
    color: var(--primary-color);
}

.mobile-menu-btn {
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    width: 24px;
    height: 18px;
    cursor: pointer;
}

.mobile-menu-btn span {
    display: block;
    width: 100%;
    height: 2px;
    background: var(--text-color);
    border-radius: 1px;
}

.mobile-search-btn {
    color: var(--text-color);
}

/* 移动端搜索框 */
.mobile-search-box {
    display: none;
    padding: 10px 15px;
    background: var(--white);
    border-top: 1px solid var(--border-color);
}

.mobile-search-box form {
    display: flex;
}

.mobile-search-box input {
    flex: 1;
    height: 36px;
    padding: 0 12px;
    border: 1px solid var(--border-color);
    border-radius: var(--radius) 0 0 var(--radius);
    outline: none;
}

.mobile-search-box button {
    width: 60px;
    height: 36px;
    background: var(--primary-color);
    color: var(--white);
    border-radius: 0 var(--radius) var(--radius) 0;
}

/* 移动端菜单 */
.mobile-menu {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    z-index: 200;
}

.mobile-menu-content {
    position: absolute;
    left: 0;
    top: 0;
    width: 280px;
    height: 100%;
    background: var(--white);
    transform: translateX(-100%);
    transition: transform 0.3s;
}

.mobile-menu.open {
    display: block;
}

.mobile-menu.open .mobile-menu-content {
    transform: translateX(0);
}

.mobile-menu-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px;
    border-bottom: 1px solid var(--border-color);
}

.mobile-menu-header .close-btn {
    font-size: 24px;
    cursor: pointer;
}

.mobile-menu-content a {
    display: block;
    padding: 15px;
    border-bottom: 1px solid var(--border-color);
    color: var(--text-color);
}

.mobile-menu-content a.active {
    color: var(--primary-color);
    background: #f0f0f0;
}

/* ===== 主容器布局 ===== */
.nav-container {
    display: flex;
    max-width: 1200px;
    margin: 20px auto;
    padding: 0 15px;
    gap: 20px;
}

/* ===== 侧边栏 ===== */
.nav-sidebar {
    width: 280px;
    flex-shrink: 0;
}

.sidebar-section {
    background: var(--white);
    border-radius: var(--radius);
    padding: 15px;
    margin-bottom: 15px;
    box-shadow: var(--shadow);
}

.sidebar-title {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 12px;
    padding-bottom: 8px;
    border-bottom: 1px solid var(--border-color);
    color: var(--text-color);
}

/* 分类图标 */
.category-icons {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 10px;
}

.category-icon-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 10px 5px;
    border-radius: var(--radius);
    transition: background 0.3s;
}

.category-icon-item:hover {
    background: #f5f5f5;
}

.category-icon-item .icon {
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--primary-color), #40a9ff);
    color: var(--white);
    font-size: 1.2rem;
    border-radius: 50%;
    margin-bottom: 6px;
}

.category-icon-item .name {
    font-size: 0.75rem;
    color: var(--text-secondary);
    text-align: center;
}

/* 国家列表 */
.country-list {
    max-height: 300px;
    overflow-y: auto;
}

.continent-group {
    margin-bottom: 12px;
}

.continent-group:last-child {
    margin-bottom: 0;
}

.continent-name {
    font-size: 0.85rem;
    font-weight: 500;
    color: var(--primary-color);
    margin-bottom: 6px;
}

.country-items {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
}

.country-item {
    display: inline-block;
    padding: 2px 8px;
    font-size: 0.75rem;
    color: var(--text-secondary);
    background: #f5f5f5;
    border-radius: 4px;
    transition: all 0.3s;
}

.country-item:hover {
    color: var(--white);
    background: var(--primary-color);
}

/* 热门网站 */
.hot-sites {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 10px;
}

.hot-site-item {
    display: flex;
    align-items: center;
    padding: 8px;
    border-radius: var(--radius);
    transition: background 0.3s;
}

.hot-site-item:hover {
    background: #f5f5f5;
}

.hot-site-item img {
    width: 32px;
    height: 32px;
    border-radius: 4px;
    margin-right: 8px;
    object-fit: contain;
}

.hot-site-item span {
    font-size: 0.8rem;
    color: var(--text-secondary);
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

/* 最新更新 */
.latest-sites {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.latest-site-item {
    display: flex;
    align-items: center;
    padding: 6px 0;
    transition: color 0.3s;
}

.latest-site-item:hover .site-name {
    color: var(--primary-color);
}

.new-tag {
    font-size: 0.65rem;
    padding: 1px 4px;
    background: #ff4d4f;
    color: var(--white);
    border-radius: 2px;
    margin-right: 8px;
}

.site-name {
    font-size: 0.85rem;
    color: var(--text-secondary);
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

/* ===== 主内容区 ===== */
.nav-main {
    flex: 1;
    min-width: 0;
}

/* 筛选栏 */
.filter-bar {
    display: flex;
    gap: 15px;
    padding: 15px;
    background: var(--white);
    border-radius: var(--radius);
    margin-bottom: 15px;
    box-shadow: var(--shadow);
}

.filter-item {
    display: flex;
    align-items: center;
    gap: 8px;
}

.filter-item label {
    font-size: 0.85rem;
    color: var(--text-secondary);
}

.filter-item select {
    height: 32px;
    padding: 0 8px;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    outline: none;
    cursor: pointer;
}

.filter-item select:focus {
    border-color: var(--primary-color);
}

/* 网站卡片网格 */
.sites-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 15px;
}

.site-card {
    background: var(--white);
    border-radius: var(--radius);
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: transform 0.3s, box-shadow 0.3s;
}

.site-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
}

.site-link {
    display: flex;
    padding: 15px;
}

.site-logo {
    width: 64px;
    height: 64px;
    flex-shrink: 0;
    margin-right: 12px;
}

.site-logo img {
    width: 100%;
    height: 100%;
    object-fit: contain;
    border-radius: 8px;
}

.site-info {
    flex: 1;
    min-width: 0;
}

.site-title {
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-color);
    margin-bottom: 4px;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.site-desc {
    font-size: 0.8rem;
    color: var(--text-light);
    margin-bottom: 8px;
    overflow: hidden;
    text-overflow: ellipsis;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
}

.site-meta {
    display: flex;
    gap: 10px;
}

.site-category,
.site-country {
    font-size: 0.7rem;
    padding: 2px 6px;
    background: #f5f5f5;
    color: var(--text-secondary);
    border-radius: 4px;
}

/* 空状态 */
.empty-state {
    grid-column: 1 / -1;
    padding: 60px 20px;
    text-align: center;
    color: var(--text-light);
}

/* ===== Footer ===== */
.nav-footer {
    background: var(--white);
    margin-top: 40px;
    padding: 20px 0;
    border-top: 1px solid var(--border-color);
}

.footer-content {
    text-align: center;
}

.footer-links {
    margin-bottom: 10px;
}

.footer-links a {
    display: inline-block;
    padding: 0 15px;
    color: var(--text-secondary);
    transition: color 0.3s;
}

.footer-links a:hover {
    color: var(--primary-color);
}

.footer-copyright p {
    font-size: 0.8rem;
    color: var(--text-light);
}

/* ===== 响应式适配 ===== */
@media (max-width: 1024px) {
    .nav-sidebar {
        width: 240px;
    }
}

@media (max-width: 768px) {
    /* 显示移动端导航 */
    .nav-header {
        display: none;
    }

    .mobile-header {
        display: flex;
        justify-content: space-between;
        align-items: center;
    }

    /* 主容器布局调整 */
    .nav-container {
        flex-direction: column;
        margin-top: 10px;
    }

    /* 侧边栏 */
    .nav-sidebar {
        width: 100%;
        order: 2;
    }

    .nav-main {
        order: 1;
    }

    /* 分类图标调整 */
    .category-icons {
        grid-template-columns: repeat(4, 1fr);
    }

    /* 筛选栏 */
    .filter-bar {
        flex-wrap: wrap;
    }

    .filter-item {
        width: calc(50% - 8px);
    }

    .filter-item label {
        display: none;
    }

    /* 网站网格 */
    .sites-grid {
        grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
        gap: 10px;
    }

    .site-link {
        flex-direction: column;
        align-items: center;
        text-align: center;
    }

    .site-logo {
        width: 48px;
        height: 48px;
        margin-right: 0;
        margin-bottom: 8px;
    }

    .site-title {
        font-size: 0.9rem;
    }

    .site-desc {
        display: none;
    }

    .site-meta {
        justify-content: center;
    }
}

@media (max-width: 480px) {
    .category-icons {
        grid-template-columns: repeat(3, 1fr);
    }

    .category-icon-item {
        padding: 8px 3px;
    }

    .category-icon-item .icon {
        width: 36px;
        height: 36px;
        font-size: 1rem;
    }

    .filter-item {
        width: 100%;
    }

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

/* ===== 滚动条美化 ===== */
.country-list::-webkit-scrollbar,
.sidebar-section::-webkit-scrollbar {
    width: 4px;
}

.country-list::-webkit-scrollbar-thumb,
.sidebar-section::-webkit-scrollbar-thumb {
    background: var(--border-color);
    border-radius: 2px;
}

.country-list::-webkit-scrollbar-track,
.sidebar-section::-webkit-scrollbar-track {
    background: transparent;
}