:root {
      --primary-color: #2563eb;
      --primary-gradient: linear-gradient(135deg, #2563eb 0%, #7c3aed 50%, #db2777 100%);
      --accent-coral: #ff5e57;
      --accent-amber: #f59e0b;
      --accent-cyan: #06b6d4;
      --accent-emerald: #10b981;
      --bg-light: #f8fafc;
      --bg-card: #ffffff;
      --text-main: #0f172a;
      --text-sub: #475569;
      --text-muted: #64748b;
      --border-color: #e2e8f0;
      --shadow-sm: 0 2px 8px rgba(15, 23, 42, 0.05);
      --shadow-md: 0 10px 25px -5px rgba(37, 99, 235, 0.08), 0 8px 10px -6px rgba(124, 58, 237, 0.05);
      --shadow-lg: 0 20px 30px -10px rgba(15, 23, 42, 0.12);
      --radius-sm: 8px;
      --radius-md: 14px;
      --radius-lg: 20px;
    }
    *, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
    html { scroll-behavior: smooth; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif; background-color: var(--bg-light); color: var(--text-main); line-height: 1.6; }
    body { background: linear-gradient(180deg, #f8fafc 0%, #f1f5f9 50%, #f8fafc 100%); min-height: 100vh; overflow-x: hidden; }
    .site-container { width: 100%; max-width: 1240px; margin: 0 auto; padding-left: 20px; padding-right: 20px; }
    .site-header { position: sticky; top: 0; z-index: 999; background: rgba(255, 255, 255, 0.95); backdrop-filter: blur(12px); border-bottom: 1px solid var(--border-color); box-shadow: var(--shadow-sm); }
    .nav-wrapper { display: flex; align-items: center; justify-content: space-between; height: 74px; }
    .brand-box { display: flex; align-items: center; gap: 12px; }
    .brand-box .ai-page-logo { height: 42px; width: auto; object-fit: contain; }
    .brand-title-group { display: flex; flex-direction: column; }
    .brand-name { font-size: 1.35rem; font-weight: 800; background: var(--primary-gradient); -webkit-background-clip: text; -webkit-text-fill-color: transparent; letter-spacing: -0.5px; }
    .brand-tagline { font-size: 0.75rem; color: var(--text-muted); font-weight: 500; }
    .nav-links { display: flex; align-items: center; gap: 0; list-style: none; }
    .nav-links li a { display: block; padding: 10px 14px; color: var(--text-sub); text-decoration: none; font-size: 0.95rem; font-weight: 600; border-radius: 6px; transition: all 0.25s ease; }
    .nav-links li a:hover { color: var(--primary-color); background: rgba(37, 99, 235, 0.05); }
    .nav-actions { display: flex; align-items: center; gap: 12px; }
    .btn { display: inline-flex; align-items: center; justify-content: center; padding: 10px 22px; font-size: 0.95rem; font-weight: 600; text-decoration: none; border-radius: var(--radius-sm); transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1); cursor: pointer; border: 1px solid transparent; }
    .btn-primary { background: var(--primary-gradient); color: #ffffff; box-shadow: 0 4px 14px rgba(37, 99, 235, 0.35); }
    .btn-primary:hover { transform: translateY(-2px); box-shadow: 0 6px 20px rgba(37, 99, 235, 0.45); }
    .btn-secondary { background: #ffffff; color: var(--primary-color); border-color: #cbd5e1; }
    .btn-secondary:hover { border-color: var(--primary-color); background: #f8fafc; }
    .mobile-menu-btn { display: none; background: transparent; border: none; font-size: 1.5rem; color: var(--text-main); cursor: pointer; padding: 6px; }

    .section-title-wrap { text-align: center; margin-bottom: 48px; }
    .section-tag { display: inline-block; padding: 4px 14px; background: rgba(37, 99, 235, 0.1); color: var(--primary-color); font-size: 0.85rem; font-weight: 700; border-radius: 20px; text-transform: uppercase; margin-bottom: 12px; letter-spacing: 0.5px; }
    .section-heading { font-size: 2.2rem; font-weight: 800; color: var(--text-main); margin-bottom: 14px; }
    .section-desc { font-size: 1.05rem; color: var(--text-sub); max-width: 760px; margin: 0 auto; }

    /* 首屏 Hero */
    .hero-section { position: relative; padding: 80px 0 60px; background: radial-gradient(circle at 10% 10%, rgba(37, 99, 235, 0.08) 0%, transparent 40%), radial-gradient(circle at 90% 90%, rgba(219, 39, 119, 0.08) 0%, transparent 40%), #ffffff; border-bottom: 1px solid var(--border-color); }
    .hero-content { text-align: center; max-width: 960px; margin: 0 auto; }
    .hero-badge { display: inline-flex; align-items: center; gap: 8px; padding: 6px 16px; background: rgba(124, 58, 237, 0.1); border: 1px solid rgba(124, 58, 237, 0.2); border-radius: 30px; font-size: 0.88rem; font-weight: 600; color: #7c3aed; margin-bottom: 24px; }
    .hero-title { font-size: 2.75rem; font-weight: 900; line-height: 1.25; margin-bottom: 24px; letter-spacing: -0.02em; color: #0f172a; }
    .hero-title .gradient-text { background: var(--primary-gradient); -webkit-background-clip: text; -webkit-text-fill-color: transparent; }
    .hero-subtitle { font-size: 1.18rem; color: var(--text-sub); margin-bottom: 36px; line-height: 1.7; max-width: 820px; margin-left: auto; margin-right: auto; }
    .hero-actions { display: flex; justify-content: center; gap: 16px; flex-wrap: wrap; margin-bottom: 48px; }
    .btn-hero-main { font-size: 1.05rem; padding: 14px 34px; border-radius: 30px; font-weight: 700; background: linear-gradient(135deg, #1e40af 0%, #6b21a8 100%); color: #ffffff; box-shadow: 0 8px 24px rgba(30, 64, 175, 0.35); text-decoration: none; transition: transform 0.2s, box-shadow 0.2s; }
    .btn-hero-main:hover { transform: translateY(-3px); box-shadow: 0 12px 28px rgba(30, 64, 175, 0.45); }
    .hero-stats-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; margin-top: 20px; }
    .stat-card { background: #ffffff; border: 1px solid var(--border-color); border-radius: var(--radius-md); padding: 24px 16px; box-shadow: var(--shadow-sm); border-top: 4px solid var(--primary-color); transition: transform 0.2s ease; }
    .stat-card:hover { transform: translateY(-4px); }
    .stat-num { font-size: 2.2rem; font-weight: 800; color: #0f172a; margin-bottom: 4px; }
    .stat-num span { font-size: 1.2rem; color: var(--primary-color); }
    .stat-label { font-size: 0.9rem; color: var(--text-muted); font-weight: 500; }

    /* 板块容器公用 */
    .section-padding { padding: 80px 0; }
    .card-grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
    .card-grid-4 { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; }
    .card-grid-2 { display: grid; grid-template-columns: repeat(2, 1fr); gap: 28px; }

    /* 平台介绍 & 服务 */
    .feature-card { background: var(--bg-card); border: 1px solid var(--border-color); border-radius: var(--radius-md); padding: 30px; box-shadow: var(--shadow-sm); transition: all 0.3s ease; position: relative; overflow: hidden; display: flex; flex-direction: column; }
    .feature-card:hover { transform: translateY(-5px); box-shadow: var(--shadow-md); border-color: rgba(37, 99, 235, 0.3); }
    .feature-icon-badge { width: 52px; height: 52px; border-radius: 12px; display: flex; align-items: center; justify-content: center; font-size: 1.5rem; margin-bottom: 20px; font-weight: 800; }
    .icon-blue { background: rgba(37, 99, 235, 0.1); color: var(--primary-color); }
    .icon-purple { background: rgba(124, 58, 237, 0.1); color: #7c3aed; }
    .icon-pink { background: rgba(219, 39, 119, 0.1); color: #db2777; }
    .icon-amber { background: rgba(245, 158, 11, 0.1); color: #f59e0b; }
    .icon-teal { background: rgba(6, 182, 212, 0.1); color: #06b6d4; }
    .icon-emerald { background: rgba(16, 185, 129, 0.1); color: #10b981; }
    .feature-card h3 { font-size: 1.25rem; font-weight: 700; color: var(--text-main); margin-bottom: 12px; }
    .feature-card p { font-size: 0.95rem; color: var(--text-sub); line-height: 1.65; margin-bottom: 16px; flex-grow: 1; }
    .feature-tags { display: flex; flex-wrap: wrap; gap: 6px; }
    .feature-tags span { font-size: 0.78rem; padding: 3px 10px; background: #f1f5f9; color: var(--text-muted); border-radius: 4px; font-weight: 500; }

    /* 模型矩阵胶囊标签 */
    .model-pills-wrap { background: #ffffff; border: 1px solid var(--border-color); border-radius: var(--radius-lg); padding: 32px; box-shadow: var(--shadow-sm); margin-top: 32px; }
    .model-pills-title { font-size: 1.15rem; font-weight: 700; color: var(--text-main); margin-bottom: 20px; text-align: center; }
    .model-pills-list { display: flex; flex-wrap: wrap; gap: 10px; justify-content: center; }
    .model-pill { background: #f8fafc; border: 1px solid #e2e8f0; padding: 6px 14px; border-radius: 20px; font-size: 0.85rem; font-weight: 600; color: var(--text-sub); transition: all 0.2s; }
    .model-pill:hover { border-color: var(--primary-color); color: var(--primary-color); background: rgba(37, 99, 235, 0.05); }

    /* 流程与步骤 */
    .process-timeline { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; position: relative; }
    .process-step { background: #ffffff; border: 1px solid var(--border-color); border-radius: var(--radius-md); padding: 26px; text-align: center; position: relative; box-shadow: var(--shadow-sm); }
    .process-number { width: 44px; height: 44px; margin: 0 auto 16px; border-radius: 50%; background: var(--primary-gradient); color: #ffffff; font-weight: 800; font-size: 1.1rem; display: flex; align-items: center; justify-content: center; }
    .process-step h4 { font-size: 1.15rem; font-weight: 700; margin-bottom: 10px; color: var(--text-main); }
    .process-step p { font-size: 0.9rem; color: var(--text-sub); line-height: 1.55; }

    /* 案例图片画廊 */
    .media-card { background: #ffffff; border-radius: var(--radius-md); overflow: hidden; border: 1px solid var(--border-color); box-shadow: var(--shadow-sm); transition: transform 0.25s ease; }
    .media-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-md); }
    .media-img-box { width: 100%; aspect-ratio: 16/9; background: #e2e8f0; overflow: hidden; position: relative; }
    .media-img-box.aspect-square { aspect-ratio: 1/1; }
    .media-img-box img { width: 100%; height: 100%; object-fit: cover; display: block; }
    .media-body { padding: 20px; }
    .media-body h4 { font-size: 1.1rem; font-weight: 700; margin-bottom: 8px; }
    .media-body p { font-size: 0.88rem; color: var(--text-sub); }

    /* 对比评测高亮区 */
    .eval-highlight-box { background: linear-gradient(135deg, rgba(37, 99, 235, 0.05) 0%, rgba(124, 58, 237, 0.05) 100%); border: 2px solid rgba(37, 99, 235, 0.2); border-radius: var(--radius-lg); padding: 36px; margin-bottom: 36px; display: flex; align-items: center; justify-content: space-between; flex-wrap: wrap; gap: 24px; }
    .eval-score-box { display: flex; align-items: center; gap: 24px; }
    .eval-score-circle { width: 100px; height: 100px; border-radius: 50%; background: var(--primary-gradient); display: flex; flex-direction: column; align-items: center; justify-content: center; color: #ffffff; box-shadow: 0 8px 20px rgba(37, 99, 235, 0.3); }
    .score-num { font-size: 2.2rem; font-weight: 900; line-height: 1; }
    .score-total { font-size: 0.8rem; opacity: 0.85; }
    .eval-badge-info h4 { font-size: 1.45rem; font-weight: 800; color: var(--text-main); margin-bottom: 6px; }
    .stars-icon { color: #f59e0b; font-size: 1.25rem; letter-spacing: 2px; }
    .table-container { width: 100%; overflow-x: auto; background: #ffffff; border-radius: var(--radius-md); border: 1px solid var(--border-color); box-shadow: var(--shadow-sm); }
    .custom-table { width: 100%; border-collapse: collapse; text-align: left; font-size: 0.95rem; }
    .custom-table th, .custom-table td { padding: 18px 22px; border-bottom: 1px solid var(--border-color); }
    .custom-table th { background: #f8fafc; font-weight: 700; color: var(--text-main); }
    .custom-table tr:hover td { background: rgba(37, 99, 235, 0.02); }
    .text-highlight { color: var(--primary-color); font-weight: 700; }

    /* 用户评论 */
    .testimonial-card { background: #ffffff; border: 1px solid var(--border-color); border-radius: var(--radius-md); padding: 26px; box-shadow: var(--shadow-sm); display: flex; flex-direction: column; justify-content: space-between; }
    .testi-content { font-size: 0.95rem; color: var(--text-sub); line-height: 1.7; margin-bottom: 20px; font-style: normal; }
    .testi-author { display: flex; align-items: center; gap: 12px; border-top: 1px solid #f1f5f9; padding-top: 16px; }
    .author-avatar { width: 44px; height: 44px; border-radius: 50%; background: linear-gradient(135deg, #3b82f6, #8b5cf6); color: #ffffff; display: flex; align-items: center; justify-content: center; font-weight: 700; font-size: 1rem; }
    .author-name { font-weight: 700; color: var(--text-main); font-size: 0.95rem; }
    .author-role { font-size: 0.82rem; color: var(--text-muted); }

    /* FAQ 展开面板 */
    .faq-container { max-width: 900px; margin: 0 auto; display: flex; flex-direction: column; gap: 14px; }
    .faq-item { background: #ffffff; border: 1px solid var(--border-color); border-radius: var(--radius-sm); overflow: hidden; transition: border-color 0.2s; }
    .faq-item.active { border-color: var(--primary-color); }
    .faq-question { padding: 18px 22px; font-weight: 700; font-size: 1.05rem; cursor: pointer; display: flex; justify-content: space-between; align-items: center; color: var(--text-main); user-select: none; }
    .faq-toggle-icon { font-size: 1.2rem; transition: transform 0.25s; color: var(--text-muted); }
    .faq-item.active .faq-toggle-icon { transform: rotate(45deg); color: var(--primary-color); }
    .faq-answer { padding: 0 22px 18px; color: var(--text-sub); font-size: 0.95rem; line-height: 1.65; display: none; }
    .faq-item.active .faq-answer { display: block; }

    /* 表单与联系 */
    .contact-wrapper { display: grid; grid-template-columns: 1.2fr 0.8fr; gap: 32px; align-items: start; }
    .form-box { background: #ffffff; border: 1px solid var(--border-color); border-radius: var(--radius-lg); padding: 36px; box-shadow: var(--shadow-sm); }
    .form-group { margin-bottom: 20px; }
    .form-group label { display: block; font-size: 0.9rem; font-weight: 700; margin-bottom: 8px; color: var(--text-main); }
    .form-control { width: 100%; padding: 12px 16px; border: 1px solid var(--border-color); border-radius: var(--radius-sm); font-size: 0.95rem; color: var(--text-main); background: #f8fafc; transition: border-color 0.2s, background 0.2s; }
    .form-control:focus { outline: none; border-color: var(--primary-color); background: #ffffff; }
    textarea.form-control { resize: vertical; min-height: 110px; }
    .contact-info-panel { background: #ffffff; border: 1px solid var(--border-color); border-radius: var(--radius-lg); padding: 36px; box-shadow: var(--shadow-sm); }
    .contact-item { margin-bottom: 24px; }
    .contact-label { font-size: 0.85rem; color: var(--text-muted); font-weight: 600; text-transform: uppercase; margin-bottom: 4px; }
    .contact-val { font-size: 1.1rem; font-weight: 700; color: var(--text-main); }
    .qr-container { text-align: center; padding: 20px; background: #f8fafc; border-radius: var(--radius-md); border: 1px solid var(--border-color); margin-top: 20px; }
    .qr-container img { max-width: 140px; height: auto; border-radius: 8px; margin-bottom: 8px; }

    /* 文章与外链 */
    .article-links-box { background: #ffffff; border: 1px solid var(--border-color); border-radius: var(--radius-md); padding: 24px; box-shadow: var(--shadow-sm); }
    .article-links-list { list-style: none; display: flex; flex-direction: column; gap: 12px; }
    .article-links-list li a { color: var(--text-sub); text-decoration: none; font-size: 0.92rem; display: flex; align-items: center; justify-content: space-between; transition: color 0.2s; }
    .article-links-list li a:hover { color: var(--primary-color); }

    /* 底部通用 */
    .site-footer { background: #0f172a; color: #94a3b8; padding: 60px 0 30px; font-size: 0.92rem; }
    .footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr 1.5fr; gap: 40px; margin-bottom: 40px; }
    .footer-brand h3 { color: #ffffff; font-size: 1.4rem; font-weight: 800; margin-bottom: 14px; }
    .footer-col h4 { color: #ffffff; font-size: 1rem; font-weight: 700; margin-bottom: 18px; }
    .footer-links { list-style: none; display: flex; flex-direction: column; gap: 10px; }
    .footer-links a { color: #94a3b8; text-decoration: none; transition: color 0.2s; }
    .footer-links a:hover { color: #ffffff; }
    .friend-links-area { border-top: 1px solid #1e293b; padding-top: 24px; margin-top: 20px; display: flex; flex-wrap: wrap; gap: 16px; align-items: center; }
    .friend-links-area a { color: #64748b; text-decoration: none; font-size: 0.85rem; }
    .friend-links-area a:hover { color: #cbd5e1; }
    .copyright-bar { border-top: 1px solid #1e293b; padding-top: 24px; margin-top: 20px; text-align: center; font-size: 0.85rem; color: #64748b; }

    /* 悬浮工具栏 */
    .floating-tools { position: fixed; right: 24px; bottom: 30px; display: flex; flex-direction: column; gap: 10px; z-index: 990; }
    .tool-btn { width: 48px; height: 48px; border-radius: 50%; background: #ffffff; border: 1px solid var(--border-color); box-shadow: var(--shadow-md); display: flex; align-items: center; justify-content: center; color: var(--text-main); text-decoration: none; font-size: 1.2rem; cursor: pointer; transition: all 0.2s; }
    .tool-btn:hover { background: var(--primary-color); color: #ffffff; }

    /* 响应式调整 */
    @media (max-width: 1024px) {
      .hero-stats-grid { grid-template-columns: repeat(2, 1fr); }
      .card-grid-4 { grid-template-columns: repeat(2, 1fr); }
      .card-grid-3 { grid-template-columns: repeat(2, 1fr); }
      .process-timeline { grid-template-columns: repeat(2, 1fr); }
      .footer-grid { grid-template-columns: 1fr 1fr; }
    }
    @media (max-width: 768px) {
      .site-header .nav-links { display: none; position: absolute; top: 74px; left: 0; width: 100%; background: #ffffff; flex-direction: column; padding: 20px; border-bottom: 1px solid var(--border-color); box-shadow: var(--shadow-md); }
      .site-header .nav-links.active { display: flex; }
      .mobile-menu-btn { display: block; }
      .hero-title { font-size: 2rem; }
      .card-grid-3, .card-grid-4, .card-grid-2 { grid-template-columns: 1fr; }
      .process-timeline { grid-template-columns: 1fr; }
      .contact-wrapper { grid-template-columns: 1fr; }
      .footer-grid { grid-template-columns: 1fr; }
      .eval-highlight-box { flex-direction: column; text-align: center; }
      .eval-score-box { flex-direction: column; }
    }