:root {
            --primary: #4361ee;
            --primary-light: #5e72e4;
            --secondary: #ff6b6b;
            --accent: #06d6a0;
            --dark: #1e293b;
            --light: #f8fafc;
            --gray: #94a3b8;
            --card-shadow: 0 5px 15px rgba(0, 0, 0, 0.08);
            --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
            
            /* 浅色主题变量 */
            --bg-body: #f8fafc;
            --text-color: #1e293b;
            --card-bg: #ffffff;
            --header-bg: linear-gradient(135deg, var(--primary), var(--primary-light));
            --card-border: #e2e8f0;
            --icon-color: #3a56d4;
            --navbar-bg: rgba(255, 255, 255, 0.95);
        }
        
        .dark-theme {
            /* 深色主题变量 */
            --bg-body: #0f172a;
            --text-color: #f1f5f9;
            --card-bg: #1e293b;
            --header-bg: linear-gradient(135deg, #0f172a, #1e293b);
            --card-border: #334155;
            --icon-color: #94a3b8;
            --navbar-bg: rgba(30, 41, 59, 0.95);
        }
        
        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
            font-family: 'Inter', 'Segoe UI', sans-serif;
        }
        
        body {
            background: var(--bg-body);
            color: var(--text-color);
            line-height: 1.6;
            min-height: 100vh;
            padding: 0;
            transition: background 0.5s ease, color 0.3s ease;
            overflow-x: hidden;
        }
        
        /* 顶部介绍区域 */
        .hero {
            background: var(--header-bg);
            color: white;
            padding: 80px 20px 60px;
            text-align: center;
            position: relative;
            overflow: hidden;
            margin-bottom: 40px;
        }
        
        .hero::before {
            content: "";
            position: absolute;
            top: -50%;
            left: -50%;
            width: 200%;
            height: 200%;
            background: radial-gradient(circle, rgba(255,255,255,0.1) 0%, rgba(255,255,255,0) 70%);
            transform: rotate(30deg);
            pointer-events: none;
        }
        
        .hero-content {
            max-width: 900px;
            margin: 0 auto;
            position: relative;
            z-index: 2;
        }
        
        .hero-icon {
            font-size: 3.5rem;
            margin-bottom: 20px;
            color: white;
            background: rgba(255, 255, 255, 0.2);
            width: 100px;
            height: 100px;
            border-radius: 50%;
            display: inline-flex;
            align-items: center;
            justify-content: center;
        }
        
        .hero h1 {
            font-size: 2.8rem;
            font-weight: 800;
            margin-bottom: 20px;
            letter-spacing: -0.5px;
            text-shadow: 0 2px 4px rgba(0,0,0,0.1);
        }
        
        .hero p {
            font-size: 1.2rem;
            max-width: 700px;
            margin: 0 auto 30px;
            opacity: 0.9;
        }
        
        .hero-stats {
            display: flex;
            justify-content: center;
            gap: 40px;
            margin-top: 40px;
            flex-wrap: wrap;
        }
        
        .stat-item {
            display: flex;
            flex-direction: column;
            align-items: center;
        }
        
        .stat-number {
            font-size: 2.2rem;
            font-weight: 700;
            margin-bottom: 5px;
        }
        
        .stat-label {
            font-size: 1rem;
            opacity: 0.9;
        }
        
        /* 导航栏 */
        .navbar {
            background: var(--navbar-bg);
            backdrop-filter: blur(10px);
            padding: 12px 0;
            position: sticky;
            top: 0;
            z-index: 100;
            box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
            border-bottom: 1px solid rgba(0, 0, 0, 0.05);
        }
        
        .nav-container {
            max-width: 1200px;
            margin: 0 auto;
            display: flex;
            justify-content: space-between;
            align-items: center;
            padding: 0 20px;
        }
        
        .logo {
            display: flex;
            align-items: center;
            gap: 10px;
            font-weight: 700;
            font-size: 1.3rem;
            color: var(--text-color);
            text-decoration: none;
        }
        
        .dark-theme .logo {
            color: #f1f5f9;
        }
        
        .nav-controls {
            display: flex;
            gap: 15px;
            align-items: center;
        }
        
        /* 菜单按钮 */
        .menu-toggle {
            display: none;
            background: none;
            border: none;
            color: var(--text-color);
            font-size: 1.5rem;
            cursor: pointer;
            margin-right: 10px;
            transition: var(--transition);
        }
        
        .dark-theme .menu-toggle {
            color: #f1f5f9;
        }
        
        /* 昼夜切换按钮 */
        .theme-switcher {
            position: relative;
            width: 50px;
            height: 26px;
            background: rgba(0, 0, 0, 0.1);
            border-radius: 13px;
            cursor: pointer;
            transition: var(--transition);
            display: flex;
            align-items: center;
            padding: 0 3px;
        }
        
        .dark-theme .theme-switcher {
            background: rgba(255, 255, 255, 0.15);
        }
        
        .theme-switcher:hover {
            transform: scale(1.05);
        }
        
        .theme-toggle {
            position: absolute;
            width: 20px;
            height: 20px;
            border-radius: 50%;
            background: white;
            transition: transform 0.3s ease;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 0.7rem;
            box-shadow: 0 2px 4px rgba(0, 0, 0, 0.2);
        }
        
        .light .theme-toggle {
            transform: translateX(0);
            background: #f59e0b;
        }
        
        .dark .theme-toggle {
            transform: translateX(24px);
            background: #94a3b8;
        }
        
        /* 主内容区 */
        .container {
            max-width: 1200px;
            margin: 0 auto 40px;
            padding: 0 20px;
            display: flex;
            gap: 30px;
        }
        
        .section-title {
            text-align: center;
            margin-bottom: 30px;
            position: relative;
            padding-bottom: 15px;
        }
        
        .section-title h2 {
            font-size: 2rem;
            color: var(--primary);
            font-weight: 700;
            letter-spacing: -0.5px;
        }
        
        .section-title::after {
            content: "";
            position: absolute;
            bottom: 0;
            left: 50%;
            transform: translateX(-50%);
            width: 60px;
            height: 4px;
            background: linear-gradient(90deg, var(--primary), var(--accent));
            border-radius: 2px;
        }
        
        /* 响应式网格布局 - 修复高度问题 */
        .posts-grid {
            display: grid;
            grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
            gap: 20px;
        }
        
        /* 帖子卡片 - 高度由内容决定 */
        .post-card {
            background: var(--card-bg);
            border-radius: 12px;
            overflow: hidden;
            box-shadow: var(--card-shadow);
            transition: var(--transition);
            display: flex;
            flex-direction: column;
            border: 1px solid var(--card-border);
            height: auto; /* 高度自适应 */
        }
        
        .post-card:hover {
            transform: translateY(-5px);
            box-shadow: 0 10px 20px rgba(0, 0, 0, 0.15);
        }
        
        .post-image-container {
            height: 160px;
            position: relative;
            overflow: hidden;
        }
        
        .post-image {
            position: absolute;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            object-fit: cover;
            transition: transform 0.7s ease;
            opacity: 0;
            transform: scale(0.95);
        }
        
        .post-image.active {
            opacity: 1;
            transform: scale(1);
        }
        
        .post-card:hover .post-image {
            transform: scale(1.05);
        }
        
        .carousel-controls {
            position: absolute;
            bottom: 10px;
            left: 50%;
            transform: translateX(-50%);
            display: flex;
            gap: 6px;
            z-index: 10;
        }
        
        .carousel-dot {
            width: 8px;
            height: 8px;
            border-radius: 50%;
            background: rgba(255, 255, 255, 0.5);
            cursor: pointer;
            transition: var(--transition);
        }
        
        .carousel-dot.active {
            background: white;
            transform: scale(1.2);
        }
        
        .post-badge {
            position: absolute;
            top: 10px;
            right: 10px;
            background: var(--secondary);
            color: white;
            padding: 5px 12px;
            border-radius: 16px;
            font-size: 0.8rem;
            font-weight: 600;
            box-shadow: 0 2px 8px rgba(0, 0, 0, 0.15);
            z-index: 2;
        }
        
        .post-content {
            padding: 16px;
            flex-grow: 1;
            display: flex;
            flex-direction: column;
        }
        
        .post-category {
            display: inline-block;
            background: rgba(6, 214, 160, 0.15);
            color: var(--accent);
            padding: 3px 10px;
            border-radius: 16px;
            font-size: 0.8rem;
            font-weight: 600;
            margin-bottom: 12px;
            align-self: flex-start;
        }
        
        .post-title {
            font-size: 1.15rem;
            margin-bottom: 10px;
            color: var(--text-color);
            line-height: 1.3;
            font-weight: 700;
            transition: var(--transition);
        }
        
        .post-card:hover .post-title {
            color: var(--primary);
        }
        
        .post-excerpt {
            color: var(--gray);
            margin-bottom: 12px;
            line-height: 1.5;
            flex-grow: 1;
            font-size: 0.9rem;
            overflow: hidden;
            display: -webkit-box;
            -webkit-line-clamp: 3;
            -webkit-box-orient: vertical;
        }
        
        .post-meta {
            display: flex;
            justify-content: space-between;
            color: var(--gray);
            font-size: 0.8rem;
            padding-top: 12px;
            margin-top: auto;
            border-top: 1px solid var(--card-border);
        }
        
        .post-meta span {
            display: flex;
            align-items: center;
            gap: 5px;
        }
        
        /* 特色功能区域 */
        .features-section {
            background: linear-gradient(135deg, var(--primary), var(--primary-light));
            color: white;
            border-radius: 16px;
            padding: 40px 30px;
            margin: 60px 0 40px;
            position: relative;
            overflow: hidden;
        }
        
        .features-section::before {
            content: "";
            position: absolute;
            top: -50%;
            right: -50%;
            width: 200%;
            height: 200%;
            background: radial-gradient(circle, rgba(255,255,255,0.1) 0%, rgba(255,255,255,0) 70%);
            transform: rotate(30deg);
            pointer-events: none;
        }
        
        .features-section h3 {
            font-size: 1.8rem;
            margin-bottom: 30px;
            text-align: center;
            position: relative;
            z-index: 2;
        }
        
        .features {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
            gap: 20px;
            position: relative;
            z-index: 2;
        }
        
        .feature {
            background: rgba(255, 255, 255, 0.12);
            padding: 20px;
            border-radius: 12px;
            text-align: center;
            transition: var(--transition);
            backdrop-filter: blur(5px);
            border: 1px solid rgba(255, 255, 255, 0.1);
        }
        
        .feature:hover {
            transform: translateY(-5px);
            background: rgba(255, 255, 255, 0.2);
            box-shadow: 0 8px 15px rgba(0, 0, 0, 0.1);
        }
        
        .feature i {
            font-size: 2.2rem;
            margin-bottom: 15px;
            color: #ffd166;
        }
        
        .feature h4 {
            font-size: 1.2rem;
            margin-bottom: 8px;
            font-weight: 600;
        }
        
        .feature p {
            opacity: 0.85;
            font-size: 0.9rem;
        }
        
        /* 底部区域 */
        footer {
            background: var(--dark);
            color: #94a3b8;
            padding: 25px 20px;
            text-align: center;
            font-size: 0.9rem;
        }
        
        .copyright {
            max-width: 1200px;
            margin: 0 auto;
        }
        
        /* === 新增侧边栏样式 === */
        .sidebar {
            flex: 0 0 250px;
            background: var(--card-bg);
            border-radius: 12px;
            padding: 20px;
            box-shadow: var(--card-shadow);
            border: 1px solid var(--card-border);
            align-self: flex-start;
            position: sticky;
            top: 80px;
            z-index: 50;
            transition: transform 0.4s ease-in-out;
            position: relative; /* 为关闭按钮定位 */
        }
        
        .main-content {
            flex: 1;
        }
        
        .sidebar h3 {
            font-size: 1.2rem;
            margin-bottom: 15px;
            padding-bottom: 10px;
            border-bottom: 1px solid var(--card-border);
        }
        
        .categories {
            list-style: none;
        }
        
        .category-item {
            padding: 8px 12px;
            margin-bottom: 8px;
            border-radius: 8px;
            cursor: pointer;
            transition: var(--transition);
        }
        
        .category-item:hover {
            background: rgba(67, 97, 238, 0.1);
        }
        
        .category-item.active {
            background: var(--primary);
            color: white;
        }
        
        /* 关闭按钮样式 */
        .sidebar-close {
            position: absolute;
            top: 15px;
            right: 15px;
            background: none;
            border: none;
            color: var(--text-color);
            font-size: 1.5rem;
            cursor: pointer;
            z-index: 101;
            display: none; /* 默认隐藏 */
        }
        
        .dark-theme .sidebar-close {
            color: #f1f5f9;
        }
        
        /* 加载更多按钮样式 */
        .load-more-container {
            grid-column: 1 / -1;
            text-align: center;
            padding: 30px 0;
        }
        
        .load-more-btn {
            background: var(--primary);
            color: white;
            border: none;
            padding: 12px 30px;
            border-radius: 30px;
            font-size: 1rem;
            font-weight: 600;
            cursor: pointer;
            transition: all 0.3s ease;
            box-shadow: 0 4px 10px rgba(67, 97, 238, 0.3);
            display: inline-flex;
            align-items: center;
            gap: 8px;
        }
        
        .load-more-btn:hover {
            background: var(--primary-light);
            transform: translateY(-2px);
            box-shadow: 0 6px 15px rgba(67, 97, 238, 0.4);
        }
        
        .load-more-btn:active {
            transform: translateY(0);
        }
        
        .load-more-btn:disabled {
            opacity: 0.7;
            cursor: not-allowed;
        }
        
        /* 移动端侧边栏 */
        .overlay {
            display: none;
            position: fixed;
            top: 0;
            left: 0;
            right: 0;
            bottom: 0;
            background: rgba(0, 0, 0, 0.5);
            z-index: 98;
            backdrop-filter: blur(3px);
        }
        
        /* 响应式设计 - 修复移动端布局问题 */
        @media (max-width: 992px) {
            .hero h1 {
                font-size: 2.3rem;
            }
            
            .hero p {
                font-size: 1.1rem;
            }
            
            .posts-grid {
                grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
                gap: 18px;
            }
            
            .post-image-container {
                height: 150px;
            }
            
            .post-content {
                padding: 14px;
            }
        }
        
        @media (max-width: 768px) {
            .hero {
                padding: 60px 20px 40px;
            }
            
            .hero h1 {
                font-size: 2rem;
            }
            
            .hero-stats {
                gap: 25px;
            }
            
            .stat-number {
                font-size: 1.8rem;
            }
            
            .section-title h2 {
                font-size: 1.8rem;
            }
            
            /* 确保手机端每行两列 - 强制两列布局 */
            .posts-grid {
                grid-template-columns: repeat(2, minmax(140px, 1fr)); /* 强制每行两列 */
                gap: 15px;
            }
            
            .post-image-container {
                height: 160px;
            }
            
            .features {
                grid-template-columns: 1fr;
                gap: 15px;
            }
            
            /* 移动端侧边栏调整 */
            .menu-toggle {
                display: block;
            }
            
            .sidebar {
                position: fixed;
                top: 0;
                left: 0;
                height: 100vh;
                width: 280px;
                border-radius: 0;
                z-index: 100;
                box-shadow: 5px 0 15px rgba(0, 0, 0, 0.1);
                transform: translateX(-100%);
                overflow-y: auto;
            }
            
            .sidebar.active {
                transform: translateX(0);
            }
            
            .overlay.active {
                display: block;
            }
            
            .sidebar-close {
                display: block; /* 在移动端显示关闭按钮 */
            }
            
            .container {
                flex-direction: column;
            }
            
            .sidebar {
                flex: 0 0 auto;
                margin-bottom: 0;
            }
        }
        
        @media (max-width: 480px) {
            .hero {
                padding: 50px 15px 30px;
            }
            
            .hero-icon {
                width: 80px;
                height: 80px;
                font-size: 2.5rem;
            }
            
            .hero h1 {
                font-size: 1.7rem;
            }
            
            .hero p {
                font-size: 1rem;
            }
            
            .hero-stats {
                gap: 15px;
                margin-top: 30px;
            }
            
            .stat-item {
                flex: 1;
                min-width: 120px;
            }
            
            .nav-container {
                flex-direction: row;
                gap: 15px;
            }
            
            .section-title h2 {
                font-size: 1.5rem;
            }
            
            .post-content {
                padding: 12px;
            }
            
            .post-title {
                font-size: 1.1rem;
            }
            
            .features-section {
                padding: 30px 20px;
                margin: 40px 0 30px;
            }
            
            .features-section h3 {
                font-size: 1.5rem;
                margin-bottom: 20px;
            }
            
            /* 超小屏幕单列显示 */
            .posts-grid {
                grid-template-columns: 1fr;
            }
        }
        
        /* 小屏幕优化 */
        @media (max-width: 360px) {
            .post-image-container {
                height: 140px;
            }
            
            .nav-container {
                flex-wrap: wrap;
                justify-content: center;
            }
            
            .logo {
                font-size: 1.1rem;
            }
        }