:root {
            --primary: #1e40af;
            --primary-vivid: #2563eb;
            --primary-light: #60a5fa;
            --primary-bg: #eff6ff;
            --accent: #0284c7;
            --accent-glow: #38bdf8;
            --text-main: #0f172a;
            --text-muted: #475569;
            --text-light: #64748b;
            --bg-body: #f8fafc;
            --bg-card: #ffffff;
            --border: #e2e8f0;
            --border-hover: #93c5fd;
            --shadow-sm: 0 2px 8px rgba(15, 23, 42, 0.05);
            --shadow-md: 0 8px 24px rgba(37, 99, 235, 0.08);
            --shadow-lg: 0 16px 36px rgba(30, 64, 175, 0.12);
            --radius: 12px;
            --transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
        }

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

        html {
            scroll-behavior: smooth;
            font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
            background-color: var(--bg-body);
            color: var(--text-main);
            line-height: 1.6;
        }

        body {
            overflow-x: hidden;
            display: flex;
            flex-direction: column;
            min-height: 100vh;
        }

        .container {
            width: 100%;
            max-width: 1240px;
            margin: 0 auto;
            padding: 0 24px;
        }

        /* 顶部导航 */
        .site-header {
            position: sticky;
            top: 0;
            z-index: 1000;
            background: rgba(255, 255, 255, 0.92);
            backdrop-filter: blur(12px);
            border-bottom: 1px solid var(--border);
            transition: var(--transition);
        }

        .header-inner {
            display: flex;
            align-items: center;
            justify-content: space-between;
            height: 76px;
        }

        .brand-logo {
            display: flex;
            align-items: center;
            gap: 12px;
            text-decoration: none;
        }

        .brand-logo img.ai-page-logo {
            height: 42px;
            width: auto;
            object-fit: contain;
        }

        .brand-name {
            font-size: 20px;
            font-weight: 800;
            color: var(--primary);
            letter-spacing: -0.5px;
        }

        .main-nav {
            display: flex;
            align-items: center;
            gap: 24px;
        }

        .nav-link {
            text-decoration: none;
            color: var(--text-muted);
            font-weight: 500;
            font-size: 15px;
            transition: var(--transition);
            position: relative;
            padding: 6px 0;
        }

        .nav-link:hover, .nav-link.active {
            color: var(--primary-vivid);
        }

        .nav-link::after {
            content: '';
            position: absolute;
            bottom: 0;
            left: 0;
            width: 0;
            height: 2px;
            background-color: var(--primary-vivid);
            transition: var(--transition);
        }

        .nav-link:hover::after {
            width: 100%;
        }

        .header-actions {
            display: flex;
            align-items: center;
            gap: 16px;
        }

        .btn {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            padding: 10px 22px;
            border-radius: 8px;
            font-weight: 600;
            font-size: 14px;
            text-decoration: none;
            cursor: pointer;
            transition: var(--transition);
            border: none;
            outline: none;
            gap: 8px;
        }

        .btn-primary {
            background: linear-gradient(135deg, var(--primary-vivid), var(--primary));
            color: #ffffff;
            box-shadow: 0 4px 14px rgba(37, 99, 235, 0.3);
        }

        .btn-primary:hover {
            transform: translateY(-2px);
            box-shadow: 0 6px 20px rgba(37, 99, 235, 0.4);
        }

        .btn-outline {
            background: transparent;
            color: var(--primary);
            border: 1px solid var(--primary);
        }

        .btn-outline:hover {
            background: var(--primary-bg);
        }

        .mobile-toggle {
            display: none;
            background: none;
            border: none;
            font-size: 24px;
            color: var(--text-main);
            cursor: pointer;
        }

        /* Hero 首屏 - 严格零图片 */
        .hero-section {
            background: linear-gradient(180deg, #ffffff 0%, #f0f7ff 100%);
            padding: 80px 0 60px;
            position: relative;
            overflow: hidden;
            border-bottom: 1px solid var(--border);
        }

        .hero-section::before {
            content: '';
            position: absolute;
            top: -100px;
            right: -100px;
            width: 400px;
            height: 400px;
            background: radial-gradient(circle, rgba(96, 165, 250, 0.15) 0%, rgba(255, 255, 255, 0) 70%);
            pointer-events: none;
        }

        .hero-content {
            text-align: center;
            max-width: 900px;
            margin: 0 auto;
        }

        .hero-badge {
            display: inline-flex;
            align-items: center;
            gap: 8px;
            background-color: var(--primary-bg);
            color: var(--primary);
            padding: 6px 16px;
            border-radius: 50px;
            font-size: 13px;
            font-weight: 600;
            border: 1px solid rgba(37, 99, 235, 0.2);
            margin-bottom: 24px;
        }

        .hero-title-h1 {
            font-size: 38px;
            line-height: 1.25;
            font-weight: 900;
            color: var(--text-main);
            letter-spacing: -1px;
            margin-bottom: 20px;
        }

        .hero-subtitle {
            font-size: 18px;
            color: var(--text-muted);
            margin-bottom: 36px;
            max-width: 780px;
            margin-left: auto;
            margin-right: auto;
        }

        .hero-ctas {
            display: flex;
            align-items: center;
            justify-content: center;
            gap: 16px;
            margin-bottom: 48px;
            flex-wrap: wrap;
        }

        .btn-large {
            padding: 14px 32px;
            font-size: 16px;
            border-radius: 10px;
        }

        .models-pills-wrapper {
            background: var(--bg-card);
            border: 1px solid var(--border);
            border-radius: var(--radius);
            padding: 20px;
            box-shadow: var(--shadow-sm);
            margin-bottom: 40px;
        }

        .models-pills-title {
            font-size: 13px;
            color: var(--text-light);
            text-transform: uppercase;
            letter-spacing: 1px;
            margin-bottom: 12px;
            font-weight: 700;
        }

        .models-pills {
            display: flex;
            flex-wrap: wrap;
            justify-content: center;
            gap: 8px;
        }

        .model-pill {
            background-color: #f1f5f9;
            color: var(--text-muted);
            font-size: 12px;
            font-weight: 600;
            padding: 4px 12px;
            border-radius: 6px;
            border: 1px solid #e2e8f0;
            transition: var(--transition);
        }

        .model-pill:hover {
            background-color: var(--primary-bg);
            color: var(--primary);
            border-color: var(--primary-light);
        }

        .hero-stats-grid {
            display: grid;
            grid-template-columns: repeat(4, 1fr);
            gap: 16px;
            margin-top: 24px;
        }

        .stat-card {
            background: var(--bg-card);
            padding: 20px;
            border-radius: var(--radius);
            border: 1px solid var(--border);
            text-align: center;
            box-shadow: var(--shadow-sm);
        }

        .stat-number {
            font-size: 28px;
            font-weight: 800;
            color: var(--primary);
        }

        .stat-label {
            font-size: 13px;
            color: var(--text-light);
            margin-top: 4px;
        }

        /* 通用 Section 样式 */
        .section {
            padding: 80px 0;
            position: relative;
        }

        .section-alt {
            background-color: #ffffff;
        }

        .section-header {
            text-align: center;
            max-width: 720px;
            margin: 0 auto 56px;
        }

        .section-tag {
            color: var(--primary-vivid);
            font-size: 14px;
            font-weight: 700;
            text-transform: uppercase;
            letter-spacing: 1px;
            margin-bottom: 8px;
            display: block;
        }

        .section-title {
            font-size: 30px;
            font-weight: 800;
            color: var(--text-main);
            letter-spacing: -0.5px;
            margin-bottom: 16px;
        }

        .section-desc {
            font-size: 16px;
            color: var(--text-muted);
        }

        /* 平台介绍与关于我们 */
        .about-grid {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 40px;
            align-items: center;
        }

        .about-card {
            background: var(--bg-card);
            border: 1px solid var(--border);
            border-radius: var(--radius);
            padding: 36px;
            box-shadow: var(--shadow-sm);
        }

        .about-card h3 {
            font-size: 22px;
            color: var(--primary);
            margin-bottom: 16px;
            font-weight: 700;
        }

        .about-card p {
            color: var(--text-muted);
            margin-bottom: 16px;
            font-size: 15px;
        }

        .feature-list {
            list-style: none;
            margin-top: 20px;
        }

        .feature-list li {
            display: flex;
            align-items: center;
            gap: 10px;
            color: var(--text-main);
            font-size: 15px;
            margin-bottom: 12px;
            font-weight: 500;
        }

        .feature-list li::before {
            content: "✓";
            color: var(--primary-vivid);
            font-weight: 900;
            background: var(--primary-bg);
            width: 20px;
            height: 20px;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 11px;
        }

        /* 统一卡片与网格 */
        .grid-3 {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: 24px;
        }

        .grid-4 {
            display: grid;
            grid-template-columns: repeat(4, 1fr);
            gap: 20px;
        }

        .card {
            background: var(--bg-card);
            border: 1px solid var(--border);
            border-radius: var(--radius);
            padding: 28px;
            transition: var(--transition);
            box-shadow: var(--shadow-sm);
            display: flex;
            flex-direction: column;
        }

        .card:hover {
            transform: translateY(-4px);
            border-color: var(--border-hover);
            box-shadow: var(--shadow-md);
        }

        .card-icon {
            width: 48px;
            height: 48px;
            border-radius: 10px;
            background: var(--primary-bg);
            color: var(--primary);
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 22px;
            font-weight: bold;
            margin-bottom: 20px;
        }

        .card-title {
            font-size: 18px;
            font-weight: 700;
            color: var(--text-main);
            margin-bottom: 12px;
        }

        .card-desc {
            font-size: 14px;
            color: var(--text-muted);
            flex-grow: 1;
        }

        /* 步骤流程 */
        .steps-wrapper {
            display: grid;
            grid-template-columns: repeat(4, 1fr);
            gap: 20px;
            position: relative;
        }

        .step-item {
            background: var(--bg-card);
            border: 1px solid var(--border);
            border-radius: var(--radius);
            padding: 24px;
            position: relative;
        }

        .step-number {
            font-size: 36px;
            font-weight: 900;
            color: rgba(37, 99, 235, 0.15);
            position: absolute;
            top: 16px;
            right: 20px;
        }

        .step-title {
            font-size: 16px;
            font-weight: 700;
            color: var(--primary);
            margin-bottom: 8px;
        }

        .step-text {
            font-size: 13px;
            color: var(--text-muted);
        }

        /* 对比表格 */
        .comparison-table-wrapper {
            background: var(--bg-card);
            border-radius: var(--radius);
            border: 1px solid var(--border);
            overflow-x: auto;
            box-shadow: var(--shadow-sm);
        }

        .comp-header-banner {
            background: linear-gradient(135deg, var(--primary), var(--primary-vivid));
            color: #ffffff;
            padding: 24px;
            display: flex;
            justify-content: space-between;
            align-items: center;
            flex-wrap: wrap;
            gap: 16px;
        }

        .comp-rating-badge {
            background: rgba(255, 255, 255, 0.2);
            padding: 8px 18px;
            border-radius: 50px;
            font-weight: 700;
            font-size: 15px;
        }

        table.comp-table {
            width: 100%;
            border-collapse: collapse;
            text-align: left;
            font-size: 14px;
        }

        table.comp-table th, table.comp-table td {
            padding: 16px 24px;
            border-bottom: 1px solid var(--border);
        }

        table.comp-table th {
            background-color: #f8fafc;
            color: var(--text-main);
            font-weight: 700;
        }

        table.comp-table tr:hover {
            background-color: #f1f5f9;
        }

        .tag-highlight {
            color: #059669;
            font-weight: 700;
        }

        /* 价格比价参考表 */
        .pricing-grid {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: 24px;
        }

        .price-card {
            background: var(--bg-card);
            border: 1px solid var(--border);
            border-radius: var(--radius);
            padding: 32px;
            text-align: center;
            transition: var(--transition);
            position: relative;
        }

        .price-card.featured {
            border: 2px solid var(--primary-vivid);
            box-shadow: var(--shadow-md);
        }

        .featured-tag {
            position: absolute;
            top: -12px;
            left: 50%;
            transform: translateX(-50%);
            background: var(--primary-vivid);
            color: #fff;
            padding: 2px 14px;
            border-radius: 12px;
            font-size: 12px;
            font-weight: 700;
        }

        .price-val {
            font-size: 32px;
            font-weight: 800;
            color: var(--primary);
            margin: 16px 0;
        }

        .price-unit {
            font-size: 14px;
            color: var(--text-light);
            font-weight: normal;
        }

        /* FAQ 手风琴 */
        .faq-accordion {
            max-width: 900px;
            margin: 0 auto;
            display: flex;
            flex-direction: column;
            gap: 16px;
        }

        .faq-item {
            background: var(--bg-card);
            border: 1px solid var(--border);
            border-radius: var(--radius);
            overflow: hidden;
            transition: var(--transition);
        }

        .faq-question {
            padding: 20px 24px;
            font-size: 16px;
            font-weight: 700;
            color: var(--text-main);
            cursor: pointer;
            display: flex;
            justify-content: space-between;
            align-items: center;
            user-select: none;
        }

        .faq-question:hover {
            color: var(--primary-vivid);
        }

        .faq-arrow {
            transition: transform 0.3s ease;
            font-weight: bold;
            color: var(--primary);
        }

        .faq-item.active .faq-arrow {
            transform: rotate(180deg);
        }

        .faq-answer {
            max-height: 0;
            overflow: hidden;
            transition: max-height 0.3s ease, padding 0.3s ease;
            padding: 0 24px;
            color: var(--text-muted);
            font-size: 14px;
            line-height: 1.7;
        }

        .faq-item.active .faq-answer {
            max-height: 300px;
            padding: 0 24px 20px 24px;
        }

        /* 用户评论 */
        .reviews-grid {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: 24px;
        }

        .review-card {
            background: var(--bg-card);
            border: 1px solid var(--border);
            border-radius: var(--radius);
            padding: 24px;
            box-shadow: var(--shadow-sm);
        }

        .review-header {
            display: flex;
            align-items: center;
            gap: 12px;
            margin-bottom: 16px;
        }

        .avatar-placeholder {
            width: 44px;
            height: 44px;
            border-radius: 50%;
            background: linear-gradient(135deg, var(--primary-light), var(--primary));
            color: #ffffff;
            display: flex;
            align-items: center;
            justify-content: center;
            font-weight: 700;
            font-size: 16px;
        }

        .reviewer-info h4 {
            font-size: 15px;
            color: var(--text-main);
            font-weight: 700;
        }

        .reviewer-info p {
            font-size: 12px;
            color: var(--text-light);
        }

        .review-stars {
            color: #f59e0b;
            font-size: 14px;
            margin-bottom: 12px;
        }

        .review-text {
            font-size: 14px;
            color: var(--text-muted);
            line-height: 1.6;
        }

        /* 案例与素材图展示 */
        .cases-grid {
            display: grid;
            grid-template-columns: repeat(2, 1fr);
            gap: 24px;
        }

        .case-card {
            background: var(--bg-card);
            border: 1px solid var(--border);
            border-radius: var(--radius);
            overflow: hidden;
            box-shadow: var(--shadow-sm);
        }

        .case-img-wrap {
            width: 100%;
            height: 240px;
            overflow: hidden;
            background-color: #e2e8f0;
        }

        .case-img-wrap img.ai-page-image {
            width: 100%;
            height: 100%;
            object-fit: cover;
            transition: var(--transition);
        }

        .case-card:hover img.ai-page-image {
            transform: scale(1.03);
        }

        .case-info {
            padding: 20px;
        }

        .case-title {
            font-size: 16px;
            font-weight: 700;
            color: var(--text-main);
            margin-bottom: 8px;
        }

        .case-desc {
            font-size: 13px;
            color: var(--text-muted);
        }

        /* 表单区 */
        .form-container {
            max-width: 760px;
            margin: 0 auto;
            background: var(--bg-card);
            border: 1px solid var(--border);
            border-radius: var(--radius);
            padding: 40px;
            box-shadow: var(--shadow-md);
        }

        .form-grid {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 20px;
        }

        .form-group {
            display: flex;
            flex-direction: column;
            gap: 8px;
        }

        .form-group.full-width {
            grid-column: span 2;
        }

        .form-label {
            font-size: 14px;
            font-weight: 600;
            color: var(--text-main);
        }

        .form-input, .form-select, .form-textarea {
            width: 100%;
            padding: 12px 16px;
            border: 1px solid var(--border);
            border-radius: 8px;
            font-size: 14px;
            color: var(--text-main);
            background: #ffffff;
            transition: var(--transition);
        }

        .form-input:focus, .form-select:focus, .form-textarea:focus {
            outline: none;
            border-color: var(--primary-vivid);
            box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.15);
        }

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

        /* 文章与知识库 */
        .articles-list {
            display: flex;
            flex-direction: column;
            gap: 16px;
        }

        .article-item {
            background: var(--bg-card);
            border: 1px solid var(--border);
            border-radius: 8px;
            padding: 16px 24px;
            display: flex;
            justify-content: space-between;
            align-items: center;
            transition: var(--transition);
        }

        .article-item:hover {
            border-color: var(--primary-vivid);
            transform: translateX(4px);
        }

        .article-link {
            text-decoration: none;
            color: var(--text-main);
            font-weight: 600;
            font-size: 15px;
        }

        .article-link:hover {
            color: var(--primary-vivid);
        }

        /* 友情链接与页脚 */
        .site-footer {
            background: #0f172a;
            color: #94a3b8;
            padding: 60px 0 30px;
            font-size: 14px;
            border-top: 1px solid #1e293b;
        }

        .footer-grid {
            display: grid;
            grid-template-columns: 2fr 1fr 1fr 1.5fr;
            gap: 40px;
            margin-bottom: 40px;
        }

        .footer-brand h3 {
            color: #ffffff;
            font-size: 20px;
            margin-bottom: 12px;
        }

        .footer-brand p {
            color: #64748b;
            font-size: 13px;
            line-height: 1.6;
        }

        .footer-title {
            color: #ffffff;
            font-size: 16px;
            font-weight: 700;
            margin-bottom: 16px;
        }

        .footer-links {
            list-style: none;
            display: flex;
            flex-direction: column;
            gap: 10px;
        }

        .footer-links a {
            color: #94a3b8;
            text-decoration: none;
            transition: var(--transition);
        }

        .footer-links a:hover {
            color: #ffffff;
        }

        .friend-links-box {
            background: #1e293b;
            padding: 20px;
            border-radius: 8px;
            margin-bottom: 30px;
        }

        .friend-links-box h4 {
            color: #ffffff;
            font-size: 14px;
            margin-bottom: 12px;
        }

        .friend-links-list {
            display: flex;
            flex-wrap: wrap;
            gap: 12px;
        }

        .friend-links-list a {
            color: #94a3b8;
            text-decoration: none;
            font-size: 13px;
        }

        .friend-links-list a:hover {
            color: #38bdf8;
        }

        .footer-bottom {
            border-top: 1px solid #1e293b;
            padding-top: 24px;
            display: flex;
            justify-content: space-between;
            align-items: center;
            flex-wrap: wrap;
            gap: 16px;
            font-size: 13px;
        }

        .ai-page-home-link {
            color: #38bdf8;
            text-decoration: none;
            font-weight: 600;
        }

        /* 悬浮客服框与回到顶部 */
        .floating-widget {
            position: fixed;
            bottom: 30px;
            right: 30px;
            z-index: 999;
            display: flex;
            flex-direction: column;
            gap: 12px;
        }

        .float-btn {
            width: 48px;
            height: 48px;
            border-radius: 50%;
            background: var(--primary-vivid);
            color: #ffffff;
            display: flex;
            align-items: center;
            justify-content: center;
            box-shadow: 0 4px 12px rgba(0,0,0,0.2);
            cursor: pointer;
            border: none;
            transition: var(--transition);
            position: relative;
        }

        .float-btn:hover {
            transform: scale(1.1);
        }

        .float-qr-modal {
            position: absolute;
            right: 60px;
            bottom: 0;
            background: #ffffff;
            padding: 16px;
            border-radius: 12px;
            box-shadow: var(--shadow-lg);
            display: none;
            text-align: center;
            width: 180px;
            border: 1px solid var(--border);
        }

        .float-qr-modal img {
            width: 140px;
            height: 140px;
            object-fit: cover;
            border-radius: 6px;
        }

        .float-btn:hover .float-qr-modal {
            display: block;
        }

        /* 响应式适配 */
        @media (max-width: 1024px) {
            .hero-stats-grid, .steps-wrapper, .grid-4 {
                grid-template-columns: repeat(2, 1fr);
            }
            .grid-3, .reviews-grid, .pricing-grid {
                grid-template-columns: repeat(2, 1fr);
            }
            .footer-grid {
                grid-template-columns: 1fr 1fr;
            }
        }

        @media (max-width: 768px) {
            .main-nav {
                display: none;
                position: absolute;
                top: 76px;
                left: 0;
                width: 100%;
                background: #ffffff;
                flex-direction: column;
                padding: 20px;
                box-shadow: var(--shadow-md);
                border-bottom: 1px solid var(--border);
            }

            .main-nav.show {
                display: flex;
            }

            .mobile-toggle {
                display: block;
            }

            .hero-title-h1 {
                font-size: 26px;
            }

            .hero-subtitle {
                font-size: 15px;
            }

            .about-grid, .cases-grid, .grid-3, .grid-4, .reviews-grid, .pricing-grid, .hero-stats-grid, .steps-wrapper {
                grid-template-columns: 1fr;
            }

            .form-grid {
                grid-template-columns: 1fr;
            }

            .form-group.full-width {
                grid-column: span 1;
            }

            .footer-grid {
                grid-template-columns: 1fr;
            }
        }