:root {
            --primary-color: #3498db;
            --secondary-color: #2ecc71;
            --accent-color: #9b59b6;
            --dark-color: #2c3e50;
            --light-color: #ecf0f1;
            --text-color: #333;
            --shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
            --transition: all 0.3s ease;
        }
        
        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
            font-family: 'Helvetica Neue', Arial, sans-serif;
        }
        
        body {
            background-color: #f9f9f9;
            color: var(--text-color);
            line-height: 1.6;
        }
        
        .container {
            width: 100%;
            max-width: 1200px;
            margin: 0 auto;
            padding: 0 20px;
        }
        
        /* 导航栏样式 */
        header {
            background: linear-gradient(135deg, var(--primary-color), var(--dark-color));
            color: white;
            padding: 1rem 0;
            position: sticky;
            top: 0;
            z-index: 100;
            box-shadow: var(--shadow);
        }
        
        nav {
            display: flex;
            justify-content: space-between;
            align-items: center;
        }
        
        .logo {
            font-size: 1.8rem;
            font-weight: bold;
            display: flex;
            align-items: center;
        }
        
        .logo i {
            margin-right: 10px;
            font-size: 2rem;
        }
        
        .nav-links {
            display: flex;
            list-style: none;
        }
        
        .nav-links li {
            margin-left: 1.5rem;
        }
        
        .nav-links a {
            color: white;
            text-decoration: none;
            font-weight: 500;
            transition: var(--transition);
            padding: 0.5rem 0;
            position: relative;
        }
        
        .nav-links a:after {
            content: '';
            position: absolute;
            width: 0;
            height: 2px;
            bottom: 0;
            left: 0;
            background-color: white;
            transition: var(--transition);
        }
        
        .nav-links a:hover:after {
            width: 100%;
        }
        
        .mobile-menu {
            display: none;
            font-size: 1.5rem;
            cursor: pointer;
        }
        
        /* 英雄区域 */
        .hero {
            background: linear-gradient(rgba(44, 62, 80, 0.8), rgba(44, 62, 80, 0.8)), url('gjjbj.jpg') no-repeat center center/cover;
            color: white;
            padding: 4rem 0;
            text-align: center;
        }
        
        .hero h1 {
            font-size: 2.5rem;
            margin-bottom: 1rem;
        }
        
        .hero p {
            font-size: 1.2rem;
            max-width: 800px;
            margin: 0 auto 2rem;
        }
        
        /* 计算器标签页 */
        .tabs {
            background-color: white;
            border-radius: 10px;
            overflow: hidden;
            box-shadow: var(--shadow);
            margin-top: -50px;
            position: relative;
            z-index: 10;
        }
        
        .tab-headers {
            display: flex;
            background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
        }
        
        .tab-header {
            padding: 1rem 2rem;
            cursor: pointer;
            color: white;
            font-weight: 500;
            flex: 1;
            text-align: center;
            transition: var(--transition);
        }
        
        .tab-header.active {
            background-color: rgba(255, 255, 255, 0.2);
        }
        
        .tab-content {
            padding: 2rem;
        }
        
        .tab-pane {
            display: none;
        }
        
        .tab-pane.active {
            display: block;
            animation: fadeIn 0.5s ease;
        }
        
        @keyframes fadeIn {
            from { opacity: 0; }
            to { opacity: 1; }
        }
        
        .calculator-form {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
            gap: 20px;
        }
        
        .form-group {
            margin-bottom: 1.5rem;
        }
        
        .form-group label {
            display: block;
            margin-bottom: 0.5rem;
            font-weight: 500;
        }
        
        .form-group input, .form-group select {
            width: 100%;
            padding: 0.8rem;
            border: 1px solid #ddd;
            border-radius: 5px;
            font-size: 1rem;
        }
        
        .btn {
            background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
            color: white;
            border: none;
            padding: 1rem 2rem;
            border-radius: 5px;
            cursor: pointer;
            font-size: 1rem;
            font-weight: 500;
            transition: var(--transition);
        }
        
        .btn:hover {
            transform: translateY(-3px);
            box-shadow: 0 10px 20px rgba(0, 0, 0, 0.1);
        }
        
        .result {
            background-color: var(--light-color);
            padding: 2rem;
            border-radius: 10px;
            margin-top: 2rem;
            display: none;
        }
        
        .result.show {
            display: block;
            animation: fadeIn 0.5s ease;
        }
        
        .result h3 {
            margin-bottom: 1rem;
            color: var(--primary-color);
        }
        
        .result-item {
            display: flex;
            justify-content: space-between;
            padding: 0.5rem 0;
            border-bottom: 1px solid #ddd;
        }
        
        /* 功能介绍 */
        .features {
            padding: 4rem 0;
        }
        
        .section-title {
            text-align: center;
            margin-bottom: 3rem;
        }
        
        .section-title h2 {
            font-size: 2.2rem;
            color: var(--dark-color);
            margin-bottom: 1rem;
        }
        
        .section-title p {
            color: #666;
            max-width: 800px;
            margin: 0 auto;
        }
        
        .features-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
            gap: 30px;
        }
        
        .feature-card {
            background-color: white;
            border-radius: 10px;
            overflow: hidden;
            box-shadow: var(--shadow);
            transition: var(--transition);
        }
        
        .feature-card:hover {
            transform: translateY(-10px);
        }
        
        .feature-img {
            height: 200px;
            overflow: hidden;
        }
        
        .feature-img img {
            width: 100%;
            height: 100%;
            object-fit: cover;
            transition: var(--transition);
        }
        
        .feature-card:hover .feature-img img {
            transform: scale(1.1);
        }
        
        .feature-content {
            padding: 1.5rem;
        }
        
        .feature-content h3 {
            margin-bottom: 1rem;
            color: var(--primary-color);
        }
        
        /* 常见问题 */
        .faq {
            background-color: var(--light-color);
            padding: 4rem 0;
        }
        
        .accordion {
            max-width: 800px;
            margin: 0 auto;
        }
        
        .accordion-item {
            background-color: white;
            border-radius: 5px;
            margin-bottom: 1rem;
            overflow: hidden;
            box-shadow: var(--shadow);
        }
        
        .accordion-header {
            padding: 1.5rem;
            cursor: pointer;
            display: flex;
            justify-content: space-between;
            align-items: center;
            font-weight: 500;
        }
        
        .accordion-content {
            padding: 0 1.5rem;
            max-height: 0;
            overflow: hidden;
            transition: max-height 0.3s ease;
        }
        
        .accordion-content.active {
            max-height: 300px;
            padding: 0 1.5rem 1.5rem;
        }
        
        /* 友情链接 */
        .friend-links {
            padding: 2rem 0;
            text-align: center;
            background-color: var(--dark-color);
            color: white;
        }
        
        .friend-links h3 {
            margin-bottom: 1.5rem;
        }
        
        .links-container {
            display: flex;
            justify-content: center;
            flex-wrap: wrap;
            gap: 20px;
        }
        
        .friend-link {
            color: white;
            text-decoration: none;
            transition: var(--transition);
        }
        
        .friend-link:hover {
            color: var(--secondary-color);
        }
        
        /* 页脚 */
        footer {
            background-color: #1a252f;
            color: white;
            padding: 2rem 0;
            text-align: center;
        }
        
        /* 响应式设计 */
        @media (max-width: 768px) {
            .nav-links {
                display: none;
                flex-direction: column;
                position: absolute;
                top: 100%;
                left: 0;
                width: 100%;
                background-color: var(--dark-color);
                padding: 1rem 0;
            }
            
            .nav-links.active {
                display: flex;
            }
            
            .nav-links li {
                margin: 0.5rem 0;
                text-align: center;
            }
            
            .mobile-menu {
                display: block;
            }
            
            .tab-headers {
                flex-direction: column;
            }
            
            .hero h1 {
                font-size: 2rem;
            }
            
            .hero p {
                font-size: 1rem;
            }
        }