/* 全局样式 */
        :root {
            --header-height: 72px;
            --primary-color: #3b82f6;
            --primary-light: #60a5fa;
            --primary-dark: #2563eb;
            --secondary-color: #1e40af;
            --accent-color: #10b981;
            --accent-light: #34d399;
            --text-primary: #f8fafc;
            --text-secondary: #94a3b8;
            --text-muted: #64748b;
            --bg-primary: #0f172a;
            --bg-secondary: #1e293b;
            --bg-card: #1e293b;
            --bg-card-hover: #263548;
            --border-color: #334155;
            --border-light: #475569;
            --success-color: #22c55e;
            --warning-color: #f59e0b;
            --error-color: #ef4444;
            --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
            --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -2px rgba(0, 0, 0, 0.1);
            --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -4px rgba(0, 0, 0, 0.1);
            --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 8px 10px -6px rgba(0, 0, 0, 0.1);
            --gradient-primary: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-dark) 100%);
            --gradient-accent: linear-gradient(135deg, var(--accent-color) 0%, #059669 100%);
        }

        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }

        html {
            scroll-behavior: smooth;
        }

        body {
            font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
            line-height: 1.7;
            color: var(--text-primary);
            background-color: var(--bg-primary);
            -webkit-font-smoothing: antialiased;
            -moz-osx-font-smoothing: grayscale;
        }

        /* 选择文本颜色 */
        ::selection {
            background: var(--primary-color);
            color: white;
        }

        /* 导航栏 */
        .navbar {
            position: fixed;
            top: 0;
            width: 100%;
            background: rgba(15, 23, 42, 0.85);
            backdrop-filter: blur(20px) saturate(180%);
            -webkit-backdrop-filter: blur(20px) saturate(180%);
            border-bottom: 1px solid rgba(51, 65, 85, 0.5);
            z-index: 1000;
            padding: 0.75rem 2rem;
            display: flex;
            justify-content: space-between;
            align-items: center;
            transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
        }

        .navbar.scrolled {
            background: rgba(15, 23, 42, 0.98);
            box-shadow: 0 4px 30px rgba(0, 0, 0, 0.3);
        }

        .nav-left {
            display: flex;
            align-items: center;
            gap: 2rem;
        }

        .logo {
            font-size: 1.75rem;
            font-weight: 800;
            background: var(--gradient-primary);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            background-clip: text;
            text-decoration: none;
            letter-spacing: -0.02em;
        }

        .nav-links {
            display: flex;
            gap: 0.5rem;
            list-style: none;
        }

        .nav-links a {
            color: var(--text-secondary);
            text-decoration: none;
            font-weight: 500;
            padding: 0.5rem 1rem;
            border-radius: 0.5rem;
            transition: all 0.2s ease;
            font-size: 0.9rem;
        }

        .nav-links a:hover {
            color: var(--text-primary);
            background: rgba(59, 130, 246, 0.1);
        }

        .nav-links a.active {
            color: var(--primary-light);
            background: rgba(59, 130, 246, 0.15);
        }

        /* 语言切换按钮 */
        .lang-switcher {
            display: flex;
            align-items: center;
            background: var(--bg-secondary);
            border-radius: 0.5rem;
            padding: 0.25rem;
            border: 1px solid var(--border-color);
        }

        .lang-btn {
            padding: 0.5rem 1rem;
            border: none;
            background: transparent;
            color: var(--text-secondary);
            cursor: pointer;
            border-radius: 0.375rem;
            font-weight: 500;
            font-size: 0.875rem;
            transition: all 0.2s ease;
        }

        .lang-btn:hover {
            color: var(--text-primary);
        }

        .lang-btn.active {
            background: var(--primary-color);
            color: white;
            box-shadow: 0 2px 8px rgba(59, 130, 246, 0.3);
        }

        /* 英雄区域 */
        .hero {
            padding: 4rem 2rem 6rem;
            text-align: center;
            background: 
                radial-gradient(ellipse at 20% 50%, rgba(59, 130, 246, 0.15) 0%, transparent 50%),
                radial-gradient(ellipse at 80% 50%, rgba(16, 185, 129, 0.1) 0%, transparent 50%),
                linear-gradient(180deg, var(--bg-primary) 0%, var(--bg-secondary) 100%);
            position: relative;
            overflow: hidden;
        }

        .hero::before {
            content: "";
            position: absolute;
            top: 0;
            left: 0;
            right: 0;
            bottom: 0;
            background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.02'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
            opacity: 0.5;
        }

        .hero-content {
            position: relative;
            z-index: 1;
        }

        .hero h1 {
            font-size: 4rem;
            font-weight: 800;
            margin-bottom: 1.5rem;
            color: var(--text-primary);
            letter-spacing: -0.03em;
            line-height: 1.1;
        }

        .hero h1 span {
            background: var(--gradient-primary);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            background-clip: text;
        }

        .hero p {
            font-size: 1.25rem;
            color: var(--text-secondary);
            max-width: 700px;
            margin: 0 auto 3rem;
            line-height: 1.8;
        }

        .hero-stats {
            display: flex;
            justify-content: center;
            gap: 4rem;
            margin: 4rem 0;
        }

        .stat {
            text-align: center;
            padding: 1.5rem 2rem;
            background: rgba(30, 41, 59, 0.5);
            border-radius: 1rem;
            border: 1px solid var(--border-color);
            backdrop-filter: blur(10px);
            transition: transform 0.3s ease, box-shadow 0.3s ease;
        }

        .stat:hover {
            transform: translateY(-5px);
            box-shadow: var(--shadow-lg);
        }

        .stat-number {
            font-size: 2.5rem;
            font-weight: 800;
            background: var(--gradient-accent);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            background-clip: text;
            margin-bottom: 0.25rem;
        }

        .stat-label {
            color: var(--text-muted);
            font-size: 0.85rem;
            font-weight: 500;
            text-transform: uppercase;
            letter-spacing: 0.05em;
        }

        .cta-buttons {
            display: flex;
            justify-content: center;
            gap: 1.5rem;
            margin-top: 3rem;
        }

        .btn {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            padding: 1rem 2rem;
            border-radius: 0.75rem;
            font-weight: 600;
            text-decoration: none;
            transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
            font-size: 1rem;
            cursor: pointer;
            border: none;
            outline: none;
        }

        .btn-primary {
            background: var(--gradient-primary);
            color: white;
            box-shadow: 0 4px 15px rgba(59, 130, 246, 0.4);
        }

        .btn-primary:hover {
            transform: translateY(-2px);
            box-shadow: 0 8px 25px rgba(59, 130, 246, 0.5);
        }

        .btn-primary:active {
            transform: translateY(0);
        }

        .btn-secondary {
            background: transparent;
            color: var(--primary-light);
            border: 2px solid var(--primary-color);
            box-shadow: 0 4px 15px rgba(59, 130, 246, 0.1);
        }

        .btn-secondary:hover {
            background: var(--primary-color);
            color: white;
            transform: translateY(-2px);
            box-shadow: 0 8px 25px rgba(59, 130, 246, 0.3);
        }

        .btn-large {
            padding: 1.25rem 2.5rem;
            font-size: 1.1rem;
        }

        /* 内容部分 */
        .section {
            padding: 6rem 2rem;
            max-width: 1200px;
            margin: 0 auto;
        }

        .section-title {
            font-size: 2.5rem;
            text-align: center;
            margin-bottom: 1rem;
            color: var(--text-primary);
            font-weight: 800;
            letter-spacing: -0.02em;
        }

        .section-subtitle {
            text-align: center;
            color: var(--text-secondary);
            margin-bottom: 4rem;
            font-size: 1.1rem;
            max-width: 600px;
            margin-left: auto;
            margin-right: auto;
        }

        /* 功能卡片 */
        .features-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
            gap: 1.5rem;
        }

        .feature-card {
            background: var(--bg-card);
            border-radius: 1.25rem;
            padding: 2rem;
            border: 1px solid var(--border-color);
            transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
            position: relative;
            overflow: hidden;
        }

        .feature-card::before {
            content: "";
            position: absolute;
            top: 0;
            left: 0;
            right: 0;
            height: 4px;
            background: var(--gradient-primary);
            transform: scaleX(0);
            transform-origin: left;
            transition: transform 0.3s ease;
        }

        .feature-card:hover {
            transform: translateY(-8px);
            box-shadow: var(--shadow-xl);
            border-color: var(--primary-color);
            background: var(--bg-card-hover);
        }

        .feature-card:hover::before {
            transform: scaleX(1);
        }

        .feature-icon {
            width: 56px;
            height: 56px;
            margin-bottom: 1.25rem;
            display: flex;
            align-items: center;
            justify-content: center;
            background: linear-gradient(135deg, rgba(59, 130, 246, 0.15) 0%, rgba(16, 185, 129, 0.1) 100%);
            border-radius: 16px;
            position: relative;
        }

        .feature-icon svg {
            width: 28px;
            height: 28px;
            stroke: var(--primary-light);
            fill: none;
            stroke-width: 2;
            stroke-linecap: round;
            stroke-linejoin: round;
        }

        .feature-icon.icon-shield svg { stroke: var(--accent-light); }
        .feature-icon.icon-dollar svg { stroke: var(--success-color); }
        .feature-icon.icon-globe svg { stroke: var(--primary-light); }
        .feature-icon.icon-cpu svg { stroke: var(--warning-color); }
        .feature-icon.icon-chart svg { stroke: var(--accent-light); }
        .feature-icon.icon-clipboard svg { stroke: var(--primary-light); }
        .feature-icon.icon-check svg { stroke: var(--success-color); }
        .feature-icon.icon-card svg { stroke: var(--primary-light); }
        .feature-icon.icon-star svg { stroke: var(--warning-color); }
        .feature-icon.icon-hand svg { stroke: var(--accent-light); }
        .feature-icon.icon-clock svg { stroke: var(--primary-light); }
        .feature-icon.icon-world svg { stroke: var(--accent-light); }
        .feature-icon.icon-mail svg { stroke: var(--primary-light); }
        .feature-icon.icon-ticket svg { stroke: var(--warning-color); }
        .feature-icon.icon-help svg { stroke: var(--accent-light); }

        .feature-title {
            font-size: 1.25rem;
            margin-bottom: 1rem;
            color: var(--text-primary);
            font-weight: 700;
        }

        .feature-desc {
            color: var(--text-secondary);
            line-height: 1.8;
            font-size: 0.95rem;
        }

        /* 双面平台 */
        .dual-platform {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 2rem;
            margin-top: 2rem;
        }

        .platform-card {
            background: var(--bg-card);
            border-radius: 1.25rem;
            padding: 2.5rem;
            border: 1px solid var(--border-color);
            transition: all 0.3s ease;
            position: relative;
            overflow: hidden;
        }

        .platform-card::after {
            content: "";
            position: absolute;
            top: 0;
            right: 0;
            width: 200px;
            height: 200px;
            background: radial-gradient(circle, rgba(59, 130, 246, 0.1) 0%, transparent 70%);
            transform: translate(50%, -50%);
        }

        .platform-card:hover {
            transform: translateY(-5px);
            box-shadow: var(--shadow-lg);
            border-color: var(--primary-color);
        }

        .platform-card h3 {
            color: var(--primary-light);
            margin-bottom: 1.5rem;
            font-size: 1.5rem;
            font-weight: 700;
            position: relative;
            z-index: 1;
        }

        .platform-card ul {
            list-style: none;
            position: relative;
            z-index: 1;
        }

        .platform-card li {
            padding: 0.75rem 0;
            color: var(--text-secondary);
            display: flex;
            align-items: flex-start;
            gap: 0.75rem;
            font-size: 0.95rem;
            border-bottom: 1px solid rgba(51, 65, 85, 0.3);
        }

        .platform-card li:last-child {
            border-bottom: none;
        }

        .platform-card li::before {
            content: "✓";
            color: var(--accent-light);
            font-weight: bold;
            flex-shrink: 0;
            width: 20px;
            height: 20px;
            display: flex;
            align-items: center;
            justify-content: center;
            background: rgba(16, 185, 129, 0.15);
            border-radius: 50%;
            font-size: 0.75rem;
        }

        /* 工作流程 */
        .workflow-steps {
            display: grid;
            grid-template-columns: repeat(4, 1fr);
            gap: 2rem;
            margin-top: 3rem;
            position: relative;
        }

        .workflow-steps::before {
            content: "";
            position: absolute;
            top: 2.5rem;
            left: 12.5%;
            right: 12.5%;
            height: 2px;
            background: linear-gradient(90deg, var(--primary-color), var(--accent-color));
            z-index: 0;
        }

        .workflow-step {
            text-align: center;
            position: relative;
            z-index: 1;
        }

        .workflow-step:not(:last-child)::after {
            display: none;
        }

        .step-number {
            width: 4rem;
            height: 4rem;
            border-radius: 50%;
            background: var(--gradient-primary);
            color: white;
            display: flex;
            align-items: center;
            justify-content: center;
            font-weight: 800;
            margin: 0 auto 1.5rem;
            font-size: 1.25rem;
            box-shadow: 0 4px 15px rgba(59, 130, 246, 0.4);
            transition: transform 0.3s ease, box-shadow 0.3s ease;
        }

        .workflow-step:hover .step-number {
            transform: scale(1.1);
            box-shadow: 0 8px 25px rgba(59, 130, 246, 0.5);
        }

        .step-title {
            font-weight: 700;
            margin-bottom: 0.75rem;
            color: var(--text-primary);
            font-size: 1.1rem;
        }

        .step-desc {
            color: var(--text-secondary);
            font-size: 0.9rem;
            line-height: 1.7;
        }

        /* 定价部分 */
        .pricing-grid {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: 2rem;
            margin-top: 3rem;
            align-items: stretch;
        }

        .pricing-card {
            background: var(--bg-card);
            border-radius: 1.5rem;
            padding: 2.5rem;
            border: 1px solid var(--border-color);
            position: relative;
            transition: all 0.3s ease;
            display: flex;
            flex-direction: column;
        }

        .pricing-card:hover {
            transform: translateY(-10px);
            box-shadow: var(--shadow-xl);
        }

        .pricing-card.popular {
            border-color: var(--primary-color);
            transform: scale(1.05);
            box-shadow: 0 20px 40px rgba(59, 130, 246, 0.3);
            background: linear-gradient(180deg, rgba(59, 130, 246, 0.1) 0%, var(--bg-card) 100%);
        }

        .pricing-card.popular:hover {
            transform: scale(1.05) translateY(-10px);
        }

        .popular-badge {
            position: absolute;
            top: -1rem;
            left: 50%;
            transform: translateX(-50%);
            background: var(--gradient-primary);
            color: white;
            padding: 0.5rem 1.5rem;
            border-radius: 2rem;
            font-size: 0.85rem;
            font-weight: 600;
            box-shadow: 0 4px 15px rgba(59, 130, 246, 0.4);
            white-space: nowrap;
        }

        .pricing-header {
            text-align: center;
            margin-bottom: 2rem;
            padding-bottom: 2rem;
            border-bottom: 1px solid var(--border-color);
        }

        .pricing-plan {
            font-size: 1.25rem;
            color: var(--text-primary);
            margin-bottom: 0.5rem;
            font-weight: 600;
        }

        .pricing-price {
            font-size: 3rem;
            font-weight: 800;
            background: var(--gradient-primary);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            background-clip: text;
            margin-bottom: 0.5rem;
        }

        .pricing-price span {
            font-size: 1rem;
            color: var(--text-muted);
            -webkit-text-fill-color: var(--text-muted);
        }

        .pricing-description {
            color: var(--text-secondary);
            font-size: 0.9rem;
            margin-top: 0.5rem;
        }

        .pricing-features {
            list-style: none;
            margin-bottom: 2rem;
            flex-grow: 1;
        }

        .pricing-features li {
            padding: 0.6rem 0;
            color: var(--text-secondary);
            display: flex;
            align-items: center;
            gap: 0.75rem;
            font-size: 0.95rem;
        }

        .pricing-features li::before {
            content: "✓";
            color: var(--accent-light);
            font-weight: bold;
            flex-shrink: 0;
            width: 20px;
            height: 20px;
            display: flex;
            align-items: center;
            justify-content: center;
            background: rgba(16, 185, 129, 0.15);
            border-radius: 50%;
            font-size: 0.75rem;
        }

        /* FAQ部分 */
        .faq-item {
            background: var(--bg-card);
            border-radius: 1rem;
            margin-bottom: 1rem;
            border: 1px solid var(--border-color);
            transition: all 0.3s ease;
            overflow: hidden;
        }

        .faq-item:hover {
            border-color: var(--primary-color);
            box-shadow: var(--shadow-md);
        }

        .faq-item.active {
            border-color: var(--primary-color);
            box-shadow: 0 4px 20px rgba(59, 130, 246, 0.2);
        }

        .faq-question {
            padding: 1.5rem 2rem;
            cursor: pointer;
            display: flex;
            justify-content: space-between;
            align-items: center;
            font-weight: 600;
            color: var(--text-primary);
            transition: background 0.3s ease;
        }

        .faq-question:hover {
            background: rgba(59, 130, 246, 0.05);
        }

        .faq-answer {
            padding: 0 2rem 1.5rem;
            color: var(--text-secondary);
            line-height: 1.8;
            display: none;
            font-size: 0.95rem;
        }

        .faq-item.active .faq-answer {
            display: block;
            animation: fadeInDown 0.3s ease;
        }

        .faq-toggle {
            width: 32px;
            height: 32px;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 1.5rem;
            color: var(--primary-color);
            transition: all 0.3s ease;
            background: rgba(59, 130, 246, 0.1);
            border-radius: 50%;
            flex-shrink: 0;
        }

        .faq-item.active .faq-toggle {
            transform: rotate(45deg);
            background: var(--primary-color);
            color: white;
        }

        @keyframes fadeInDown {
            from {
                opacity: 0;
                transform: translateY(-10px);
            }
            to {
                opacity: 1;
                transform: translateY(0);
            }
        }

        /* 联系表单 */
        .contact-form {
            max-width: 600px;
            margin: 0 auto;
            background: var(--bg-card);
            padding: 2.5rem;
            border-radius: 1.25rem;
            border: 1px solid var(--border-color);
        }

        .form-group {
            margin-bottom: 1.5rem;
        }

        .form-group label {
            display: block;
            margin-bottom: 0.75rem;
            color: var(--text-primary);
            font-weight: 600;
            font-size: 0.95rem;
        }

        .form-group input,
        .form-group textarea,
        .form-group select {
            width: 100%;
            padding: 1rem 1.25rem;
            background: var(--bg-primary);
            border: 1px solid var(--border-color);
            border-radius: 0.75rem;
            color: var(--text-primary);
            font-size: 1rem;
            transition: all 0.3s ease;
            outline: none;
        }

        .form-group input:focus,
        .form-group textarea:focus,
        .form-group select:focus {
            border-color: var(--primary-color);
            box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.2);
        }

        .form-group input::placeholder,
        .form-group textarea::placeholder {
            color: var(--text-muted);
        }

        .form-group textarea {
            height: 150px;
            resize: vertical;
            min-height: 120px;
        }

        .form-group select {
            cursor: pointer;
            appearance: none;
            background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%2394a3b8' d='M6 8L1 3h10z'/%3E%3C/svg%3E");
            background-repeat: no-repeat;
            background-position: right 1rem center;
            padding-right: 2.5rem;
        }

        /* 页脚 */
        .footer {
            background: linear-gradient(180deg, var(--bg-secondary) 0%, var(--bg-primary) 100%);
            padding: 5rem 2rem 2rem;
            border-top: 1px solid var(--border-color);
        }

        .footer-grid {
            display: grid;
            grid-template-columns: repeat(4, 1fr);
            gap: 3rem;
            max-width: 1200px;
            margin: 0 auto;
        }

        .footer-section h4 {
            color: var(--text-primary);
            margin-bottom: 1.5rem;
            font-size: 1.1rem;
            font-weight: 700;
        }

        .footer-section p {
            color: var(--text-secondary);
            line-height: 1.8;
            font-size: 0.95rem;
        }

        .footer-links {
            list-style: none;
        }

        .footer-links li {
            margin-bottom: 0.75rem;
        }

        .footer-links a {
            color: var(--text-secondary);
            text-decoration: none;
            transition: all 0.3s ease;
            font-size: 0.95rem;
            display: inline-block;
        }

        .footer-links a:hover {
            color: var(--primary-light);
            transform: translateX(5px);
        }

        .footer-bottom {
            text-align: center;
            margin-top: 4rem;
            padding-top: 2rem;
            border-top: 1px solid var(--border-color);
            color: var(--text-muted);
            font-size: 0.9rem;
        }

        .footer-bottom p {
            margin-bottom: 0.5rem;
        }

        /* 响应式设计 */
        @media (max-width: 1024px) {
            .workflow-steps {
                grid-template-columns: repeat(2, 1fr);
                gap: 3rem;
            }
            
            .workflow-steps::before {
                display: none;
            }
            
            .pricing-grid {
                grid-template-columns: 1fr;
                max-width: 400px;
                margin-left: auto;
                margin-right: auto;
            }
            
            .pricing-card.popular {
                transform: none;
            }
            
            .pricing-card.popular:hover {
                transform: translateY(-10px);
            }
        }

        @media (max-width: 768px) {
            .navbar {
                padding: 1rem;
            }
            
            .nav-left {
                flex-direction: column;
                gap: 1rem;
            }
            
            .nav-links {
                display: none;
            }
            
            .hero {
                padding: 8rem 1.5rem 4rem;
            }
            
            .hero h1 {
                font-size: 2.5rem;
            }
            
            .hero-stats {
                flex-direction: column;
                gap: 1rem;
                align-items: center;
            }
            
            .stat {
                width: 100%;
                max-width: 300px;
            }
            
            .cta-buttons {
                flex-direction: column;
                align-items: center;
            }
            
            .btn-large {
                width: 100%;
                max-width: 300px;
            }
            
            .section {
                padding: 4rem 1.5rem;
            }
            
            .section-title {
                font-size: 2rem;
            }
            
            .dual-platform {
                grid-template-columns: 1fr;
            }
            
            .workflow-steps {
                grid-template-columns: 1fr;
                gap: 2rem;
            }
            
            .footer-grid {
                grid-template-columns: 1fr 1fr;
                gap: 2rem;
            }
        }

        @media (max-width: 480px) {
            .hero h1 {
                font-size: 2rem;
            }
            
            .hero p {
                font-size: 1rem;
            }
            
            .features-grid {
                grid-template-columns: 1fr;
            }
            
            .footer-grid {
                grid-template-columns: 1fr;
            }
            
            .contact-form {
                padding: 1.5rem;
            }
        }

        /* 动画 */
        @keyframes fadeIn {
            from {
                opacity: 0;
                transform: translateY(30px);
            }
            to {
                opacity: 1;
                transform: translateY(0);
            }
        }

        .section {
            animation: fadeIn 0.6s ease-out;
        }

        .feature-card {
            opacity: 0;
            animation: fadeIn 0.6s ease-out forwards;
        }

        .feature-card:nth-child(1) { animation-delay: 0.1s; }
        .feature-card:nth-child(2) { animation-delay: 0.2s; }
        .feature-card:nth-child(3) { animation-delay: 0.3s; }
        .feature-card:nth-child(4) { animation-delay: 0.4s; }
        .feature-card:nth-child(5) { animation-delay: 0.5s; }
        .feature-card:nth-child(6) { animation-delay: 0.6s; }

        /* 页面加载动画 */
        body {
            opacity: 0;
            transition: opacity 0.5s ease;
        }
    

/* ===== 布局：固定页眉 + 粘性页脚 ===== */
html {
    scroll-behavior: smooth;
    scroll-padding-top: var(--header-height);
}
body {
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}
.main-content {
    flex: 1 0 auto;
    padding-top: var(--header-height);
}
.footer {
    flex-shrink: 0;
}
section[id] {
    scroll-margin-top: calc(var(--header-height) + 16px);
}

/* ===== 移动端汉堡菜单按钮 ===== */
.nav-toggle {
    display: none;
    flex-direction: column;
    justify-content: center;
    gap: 5px;
    width: 42px;
    height: 42px;
    padding: 0;
    border: none;
    background: transparent;
    cursor: pointer;
}
.nav-toggle span {
    display: block;
    height: 2px;
    width: 24px;
    background: var(--text-primary);
    border-radius: 2px;
    transition: transform 0.3s ease, opacity 0.3s ease;
}
.nav-toggle.active span:nth-child(1) {
    transform: translateY(7px) rotate(45deg);
}
.nav-toggle.active span:nth-child(2) {
    opacity: 0;
}
.nav-toggle.active span:nth-child(3) {
    transform: translateY(-7px) rotate(-45deg);
}

/* ===== 移动端适配优化 ===== */
@media (max-width: 768px) {
    :root { --header-height: 60px; }
    .nav-toggle { display: flex; }
    .nav-left { flex-direction: row; gap: 1rem; }
    .nav-links {
        display: flex;
        flex-direction: column;
        position: fixed;
        top: var(--header-height);
        left: 0;
        right: 0;
        background: var(--bg-primary);
        border-bottom: 1px solid var(--border-color);
        padding: 1rem 1.5rem 1.5rem;
        gap: 0.25rem;
        max-height: calc(100vh - var(--header-height));
        overflow-y: auto;
        transform: translateY(-150%);
        transition: transform 0.3s ease;
        box-shadow: 0 12px 30px rgba(0, 0, 0, 0.35);
    }
    .nav-links.nav-open { transform: translateY(0); }
    .nav-links li {
        width: 100%;
        border-bottom: 1px solid rgba(71, 85, 105, 0.25);
    }
    .nav-links li:last-child { border-bottom: none; }
    .nav-links a {
        display: block;
        padding: 0.85rem 0.25rem;
        font-size: 1rem;
    }
    .hero { padding: 2.5rem 1.5rem 3rem; }
    .section { padding: 3rem 1.5rem; }
}

@media (max-width: 480px) {
    .nav-left .logo { font-size: 1.25rem; }
    .lang-btn { padding: 0.3rem 0.6rem; font-size: 0.85rem; }
}