:root {
            --primary-color: #2C3E50; /* 深蓝色，符合电子书阅读的沉稳感 */
            --secondary-color: #3498DB;
            --accent-color: #E74C3C;
            --light-color: #ECF0F1;
            --dark-color: #1A252F;
            --text-color: #333;
            --light-text: #666;
            --background-color: #f8f9fa;
            --white: #fff;
            --shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
            --border-radius: 8px;
            --transition: all 0.3s ease;
        }
        
        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
            font-family: 'Segoe UI', 'Microsoft YaHei', sans-serif;
        }
        
        body {
            line-height: 1.6;
            color: var(--text-color);
            background-color: var(--background-color);
            overflow-x: hidden;
        }
        
        /* 导航栏样式 */
        header {
            background-color: var(--white);
            box-shadow: var(--shadow);
            position: sticky;
            top: 0;
            z-index: 1000;
        }
        
        .container {
            width: 100%;
            max-width: 1200px;
            margin: 0 auto;
            padding: 0 20px;
        }
        
        .nav-container {
            display: flex;
            justify-content: space-between;
            align-items: center;
            padding: 15px 0;
        }
        
        .logo {
            display: flex;
            align-items: center;
            font-weight: 700;
            font-size: 28px;
            color: var(--primary-color);
            text-decoration: none;
        }
        
        .logo i {
            margin-right: 10px;
            font-size: 32px;
            color: var(--secondary-color);
        }
        
        .nav-links {
            display: flex;
            list-style: none;
        }
        
        .nav-links li {
            margin-left: 30px;
        }
        
        .nav-links a {
            text-decoration: none;
            color: var(--text-color);
            font-weight: 500;
            font-size: 16px;
            transition: var(--transition);
            position: relative;
        }
        
        .nav-links a:hover {
            color: var(--secondary-color);
        }
        
        .nav-links a:after {
            content: '';
            position: absolute;
            width: 0;
            height: 2px;
            background: var(--secondary-color);
            left: 0;
            bottom: -5px;
            transition: var(--transition);
        }
        
        .nav-links a:hover:after {
            width: 100%;
        }
        
        .download-btn-nav {
            background-color: var(--accent-color);
            color: var(--white);
            padding: 8px 20px;
            border-radius: var(--border-radius);
            font-weight: 600;
            transition: var(--transition);
        }
        
        .download-btn-nav:hover {
            background-color: #c0392b;
            color: var(--white);
            transform: translateY(-2px);
        }
        
        .mobile-menu-btn {
            display: none;
            background: none;
            border: none;
            font-size: 24px;
            color: var(--primary-color);
            cursor: pointer;
        }
        
        /* 英雄区域样式 */
        .hero {
            padding: 100px 0 80px;
            background: linear-gradient(135deg, var(--primary-color) 0%, #4A6491 100%);
            color: var(--white);
            position: relative;
            overflow: hidden;
        }
        
        .hero:before {
            content: '';
            position: absolute;
            top: 0;
            right: 0;
            width: 50%;
            height: 100%;
            background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100" preserveAspectRatio="none"><path d="M0,0 L100,0 L100,100 Z" fill="rgba(255,255,255,0.05)"/></svg>') no-repeat;
            background-size: cover;
        }
        
        .hero-content {
            display: flex;
            align-items: center;
            justify-content: space-between;
            position: relative;
            z-index: 1;
        }
        
        .hero-text {
            flex: 1;
            padding-right: 40px;
        }
        
        .hero-text h1 {
            font-size: 48px;
            line-height: 1.2;
            margin-bottom: 20px;
            color: var(--white);
        }
        
        .hero-text p {
            font-size: 18px;
            color: rgba(255, 255, 255, 0.9);
            margin-bottom: 30px;
            max-width: 600px;
        }
        
        .hero-image {
            flex: 1;
            text-align: center;
            animation: float 6s ease-in-out infinite;
        }
        
        @keyframes float {
            0% { transform: translateY(0px); }
            50% { transform: translateY(-15px); }
            100% { transform: translateY(0px); }
        }
        
        .hero-image img {
            max-width: 100%;
            height: auto;
            border-radius: var(--border-radius);
            box-shadow: 0 20px 40px rgba(0, 0, 0, 0.3);
            transition: var(--transition);
        }
        
        .hero-image img:hover {
            transform: scale(1.02);
        }
        
        /* 下载按钮样式 */
        .download-btn {
            display: inline-block;
            background-color: var(--accent-color);
            color: var(--white);
            padding: 15px 40px;
            font-size: 18px;
            font-weight: 600;
            border-radius: var(--border-radius);
            text-decoration: none;
            transition: var(--transition);
            box-shadow: 0 6px 20px rgba(231, 76, 60, 0.3);
            margin-top: 10px;
            margin-bottom: 20px;
        }
        
        .download-btn:hover {
            background-color: #c0392b;
            transform: translateY(-3px);
            box-shadow: 0 10px 25px rgba(231, 76, 60, 0.4);
        }
        
        .download-btn i {
            margin-right: 10px;
        }
        
        .platform-badges {
            display: flex;
            flex-wrap: wrap;
            gap: 15px;
            margin-top: 20px;
        }
        
        .platform-badge {
            background: rgba(255, 255, 255, 0.1);
            border-radius: 20px;
            padding: 5px 15px;
            font-size: 14px;
            display: flex;
            align-items: center;
            backdrop-filter: blur(10px);
        }
        
        .platform-badge i {
            margin-right: 5px;
        }
        
        /* 功能介绍区域 */
        .features {
            padding: 100px 0;
            background-color: var(--white);
        }
        
        .section-title {
            text-align: center;
            margin-bottom: 60px;
            font-size: 36px;
            color: var(--primary-color);
            position: relative;
        }
        
        .section-title:after {
            content: '';
            position: absolute;
            width: 80px;
            height: 4px;
            background-color: var(--accent-color);
            bottom: -15px;
            left: 50%;
            transform: translateX(-50%);
        }
        
        .feature-cards {
            display: grid;
            grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
            gap: 30px;
            margin-top: 40px;
        }
        
        .feature-card {
            background-color: var(--light-color);
            border-radius: var(--border-radius);
            padding: 30px;
            box-shadow: var(--shadow);
            transition: var(--transition);
            border-top: 4px solid var(--secondary-color);
            position: relative;
            overflow: hidden;
        }
        
        .feature-card:hover {
            transform: translateY(-10px);
            box-shadow: 0 15px 30px rgba(0, 0, 0, 0.15);
        }
        
        .feature-icon {
            background-color: var(--secondary-color);
            color: var(--white);
            width: 60px;
            height: 60px;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            margin-bottom: 20px;
            font-size: 24px;
        }
        
        .feature-card h3 {
            font-size: 22px;
            margin-bottom: 15px;
            color: var(--primary-color);
        }
        
        .feature-card p {
            color: var(--light-text);
        }
        
        /* 下载区域样式 */
        .download-section {
            padding: 100px 0;
            background-color: var(--light-color);
        }
        
        .download-options {
            display: flex;
            justify-content: center;
            align-items: stretch;
            flex-wrap: wrap;
            gap: 40px;
            margin-top: 40px;
        }
        
        .download-box {
            background-color: var(--white);
            border-radius: var(--border-radius);
            padding: 40px;
            box-shadow: var(--shadow);
            max-width: 500px;
            width: 100%;
            display: flex;
            flex-direction: column;
            transition: var(--transition);
        }
        
        .download-box:hover {
            transform: translateY(-10px);
            box-shadow: 0 15px 30px rgba(0, 0, 0, 0.15);
        }
        
        .download-box h3 {
            color: var(--primary-color);
            margin-bottom: 20px;
            font-size: 24px;
            display: flex;
            align-items: center;
        }
        
        .download-box h3 i {
            margin-right: 10px;
            color: var(--accent-color);
        }
        
        .quark-download {
            border-top: 4px solid var(--accent-color);
        }
        
        .qrcode {
            margin: 25px auto;
            text-align: center;
            padding: 15px;
            background: var(--light-color);
            border-radius: var(--border-radius);
            max-width: 220px;
        }
        
        .qrcode img {
            width: 180px;
            height: 180px;
            border-radius: 8px;
        }
        
        .quark-link {
            display: block;
            margin-top: 15px;
            color: var(--secondary-color);
            font-weight: 600;
            word-break: break-all;
            text-decoration: none;
            transition: var(--transition);
        }
        
        .quark-link:hover {
            color: var(--accent-color);
            text-decoration: underline;
        }
        
        /* 使用教程区域 */
        .tutorial {
            padding: 100px 0;
            background-color: var(--white);
        }
        
        .steps {
            max-width: 900px;
            margin: 50px auto 0;
            position: relative;
        }
        
        .steps:before {
            content: '';
            position: absolute;
            left: 30px;
            top: 0;
            bottom: 0;
            width: 4px;
            background: var(--light-color);
            z-index: 1;
        }
        
        .step {
            display: flex;
            margin-bottom: 50px;
            align-items: flex-start;
            position: relative;
            z-index: 2;
        }
        
        .step-number {
            background-color: var(--secondary-color);
            color: var(--white);
            width: 60px;
            height: 60px;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            font-weight: 700;
            font-size: 24px;
            margin-right: 30px;
            flex-shrink: 0;
            box-shadow: 0 5px 15px rgba(52, 152, 219, 0.3);
        }
        
        .step-content {
            background-color: var(--light-color);
            padding: 25px;
            border-radius: var(--border-radius);
            flex: 1;
            box-shadow: var(--shadow);
        }
        
        .step-content h3 {
            margin-bottom: 10px;
            color: var(--primary-color);
            font-size: 22px;
        }
        
        .step-content p {
            margin-bottom: 15px;
        }
        
        .code-snippet {
            background-color: var(--dark-color);
            color: var(--light-color);
            padding: 15px;
            border-radius: 5px;
            font-family: 'Courier New', monospace;
            margin-top: 10px;
            overflow-x: auto;
        }
        
        /* 常见问题区域 */
        .faq {
            padding: 100px 0;
            background-color: var(--light-color);
        }
        
        .faq-container {
            max-width: 900px;
            margin: 50px auto 0;
        }
        
        .faq-item {
            background-color: var(--white);
            margin-bottom: 15px;
            border-radius: var(--border-radius);
            overflow: hidden;
            box-shadow: 0 2px 10px rgba(0,0,0,0.05);
            transition: var(--transition);
        }
        
        .faq-item:hover {
            box-shadow: 0 5px 15px rgba(0,0,0,0.1);
        }
        
        .faq-question {
            padding: 20px;
            cursor: pointer;
            display: flex;
            justify-content: space-between;
            align-items: center;
            font-weight: 600;
            font-size: 18px;
            background-color: var(--white);
            transition: var(--transition);
        }
        
        .faq-question:hover {
            background-color: #f9f9f9;
        }
        
        .faq-question i {
            transition: transform 0.3s;
            color: var(--secondary-color);
        }
        
        .faq-answer {
            padding: 0 20px;
            max-height: 0;
            overflow: hidden;
            transition: max-height 0.3s, padding 0.3s;
        }
        
        .faq-item.active .faq-answer {
            padding: 0 20px 20px;
            max-height: 500px;
        }
        
        .faq-item.active .faq-question {
            background-color: #f9f9f9;
        }
        
        .faq-item.active .faq-question i {
            transform: rotate(180deg);
        }
        
        /* 页脚样式 */
        footer {
            background-color: var(--dark-color);
            color: var(--white);
            padding: 60px 0 20px;
        }
        
        .footer-content {
            display: flex;
            justify-content: space-between;
            flex-wrap: wrap;
            margin-bottom: 40px;
        }
        
        .footer-column {
            flex: 1;
            min-width: 250px;
            margin-bottom: 30px;
        }
        
        .footer-column h3 {
            font-size: 20px;
            margin-bottom: 20px;
            color: var(--light-color);
            position: relative;
            padding-bottom: 10px;
        }
        
        .footer-column h3:after {
            content: '';
            position: absolute;
            left: 0;
            bottom: 0;
            width: 40px;
            height: 2px;
            background-color: var(--accent-color);
        }
        
        .footer-links {
            list-style: none;
        }
        
        .footer-links li {
            margin-bottom: 12px;
        }
        
        .footer-links a {
            color: #ccc;
            text-decoration: none;
            transition: var(--transition);
            display: flex;
            align-items: center;
        }
        
        .footer-links a:hover {
            color: var(--secondary-color);
            padding-left: 5px;
        }
        
        .footer-links a i {
            margin-right: 8px;
            font-size: 14px;
        }
        
        .copyright {
            text-align: center;
            padding-top: 30px;
            border-top: 1px solid rgba(255, 255, 255, 0.1);
            font-size: 14px;
            color: #aaa;
        }
        
        /* 浮动下载按钮 */
        .floating-download-btn {
            position: fixed;
            bottom: 30px;
            right: 30px;
            background-color: var(--accent-color);
            color: var(--white);
            width: 60px;
            height: 60px;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 24px;
            box-shadow: 0 5px 20px rgba(0, 0, 0, 0.3);
            z-index: 999;
            cursor: pointer;
            transition: var(--transition);
            text-decoration: none;
        }
        
        .floating-download-btn:hover {
            background-color: #c0392b;
            transform: scale(1.1);
            box-shadow: 0 8px 25px rgba(0, 0, 0, 0.4);
        }
        
        /* 响应式设计 */
        @media (max-width: 992px) {
            .hero-content {
                flex-direction: column;
            }
            
            .hero-text {
                padding-right: 0;
                text-align: center;
                margin-bottom: 40px;
            }
            
            .hero-text h1 {
                font-size: 40px;
            }
            
            .hero:before {
                width: 100%;
                opacity: 0.3;
            }
        }
        
        @media (max-width: 768px) {
            .nav-links {
                display: none;
                position: absolute;
                top: 70px;
                left: 0;
                width: 100%;
                background-color: var(--white);
                flex-direction: column;
                padding: 20px;
                box-shadow: 0 10px 20px rgba(0,0,0,0.1);
            }
            
            .nav-links.active {
                display: flex;
            }
            
            .nav-links li {
                margin: 10px 0;
                margin-left: 0;
            }
            
            .mobile-menu-btn {
                display: block;
            }
            
            .hero-text h1 {
                font-size: 34px;
            }
            
            .section-title {
                font-size: 30px;
            }
            
            .step:before {
                left: 30px;
            }
            
            .steps:before {
                left: 30px;
            }
        }
        
        @media (max-width: 576px) {
            .hero {
                padding: 80px 0 60px;
            }
            
            .hero-text h1 {
                font-size: 28px;
            }
            
            .download-btn {
                padding: 12px 30px;
                font-size: 16px;
            }
            
            .section-title {
                font-size: 26px;
            }
            
            .feature-card, .download-box {
                padding: 20px;
            }
            
            .step {
                flex-direction: column;
            }
            
            .step-number {
                margin-right: 0;
                margin-bottom: 15px;
            }
            
            .steps:before {
                left: 30px;
            }
        }