:root {
      --primary: #2563eb;
      --primary-dark: #1d4ed8;
      --accent-coral: #ff5e36;
      --accent-purple: #7c3aed;
      --accent-cyan: #06b6d4;
      --bg-main: #f8fafc;
      --bg-card: #ffffff;
      --text-main: #0f172a;
      --text-muted: #475569;
      --border-color: #e2e8f0;
      --gradient-brand: linear-gradient(135deg, #2563eb 0%, #7c3aed 50%, #ff5e36 100%);
      --gradient-subtle: linear-gradient(180deg, #ffffff 0%, #f1f5f9 100%);
      --shadow-sm: 0 1px 3px rgba(0,0,0,0.05);
      --shadow-md: 0 4px 16px rgba(0,0,0,0.07);
      --shadow-lg: 0 10px 30px rgba(37,99,235,0.08);
      --radius-sm: 8px;
      --radius-md: 14px;
      --radius-lg: 20px;
    }
    *, *::before, *::after {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }
    html {
      scroll-behavior: smooth;
      font-size: 16px;
    }
    body {
      font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
      background-color: var(--bg-main);
      color: var(--text-main);
      line-height: 1.6;
      overflow-x: hidden;
    }
    a {
      color: inherit;
      text-decoration: none;
      transition: all 0.25s ease;
    }
    img {
      display: block;
      max-width: 100%;
      height: auto;
    }
    .container {
      width: 100%;
      max-width: 1240px;
      margin: 0 auto;
      padding: 0 24px;
    }
    .section-wrap {
      padding: 70px 0;
      position: relative;
    }
    .section-head {
      text-align: center;
      max-width: 780px;
      margin: 0 auto 48px auto;
    }
    .section-tag {
      display: inline-block;
      padding: 6px 16px;
      font-size: 0.85rem;
      font-weight: 600;
      color: var(--primary);
      background: rgba(37, 99, 235, 0.08);
      border-radius: 50px;
      margin-bottom: 12px;
      letter-spacing: 0.5px;
    }
    .section-title {
      font-size: 2.1rem;
      font-weight: 700;
      color: var(--text-main);
      margin-bottom: 14px;
      line-height: 1.3;
    }
    .section-desc {
      font-size: 1.05rem;
      color: var(--text-muted);
    }
    
    /* 顶部导航 */
    .site-header {
      position: sticky;
      top: 0;
      z-index: 1000;
      background: rgba(255, 255, 255, 0.94);
      backdrop-filter: blur(12px);
      border-bottom: 1px solid var(--border-color);
      box-shadow: var(--shadow-sm);
    }
    .nav-inner {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 72px;
    }
    .brand-box {
      display: flex;
      align-items: center;
      gap: 12px;
    }
    .brand-box .ai-page-logo {
      height: 40px;
      width: auto;
    }
    .brand-text {
      font-size: 1.25rem;
      font-weight: 800;
      background: var(--gradient-brand);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
    }
    .nav-links {
      display: flex;
      align-items: center;
      gap: 0;
      list-style: none;
    }
    .nav-links a {
      padding: 8px 14px;
      font-size: 0.95rem;
      font-weight: 500;
      color: var(--text-main);
      border-radius: var(--radius-sm);
    }
    .nav-links a:hover {
      color: var(--primary);
      background: rgba(37, 99, 235, 0.05);
    }
    .nav-actions {
      display: flex;
      align-items: center;
      gap: 12px;
    }
    .btn-nav-primary {
      padding: 9px 20px;
      font-size: 0.92rem;
      font-weight: 600;
      color: #ffffff !important;
      background: var(--gradient-brand);
      border-radius: 50px;
      box-shadow: 0 4px 12px rgba(37, 99, 235, 0.25);
    }
    .btn-nav-primary:hover {
      opacity: 0.92;
      transform: translateY(-1px);
    }
    .menu-toggle {
      display: none;
      background: none;
      border: none;
      cursor: pointer;
      padding: 6px;
    }
    .menu-toggle span {
      display: block;
      width: 24px;
      height: 2px;
      background: var(--text-main);
      margin: 5px 0;
      transition: 0.3s;
    }

    /* Hero 首屏 - 纯色/渐变/几何/动效，无图片 */
    .hero-section {
      padding: 80px 0 90px;
      background: radial-gradient(circle at 10% 20%, rgba(37, 99, 235, 0.08) 0%, transparent 40%),
                  radial-gradient(circle at 90% 80%, rgba(255, 94, 54, 0.08) 0%, transparent 40%),
                  linear-gradient(180deg, #ffffff 0%, var(--bg-main) 100%);
      text-align: center;
      position: relative;
    }
    .hero-badge {
      display: inline-flex;
      align-items: center;
      gap: 8px;
      padding: 6px 18px;
      background: #ffffff;
      border: 1px solid rgba(37, 99, 235, 0.2);
      border-radius: 30px;
      box-shadow: var(--shadow-sm);
      font-size: 0.9rem;
      font-weight: 600;
      color: var(--primary);
      margin-bottom: 24px;
    }
    .hero-badge .pulse-dot {
      width: 8px;
      height: 8px;
      background: var(--accent-coral);
      border-radius: 50%;
      box-shadow: 0 0 0 rgba(255, 94, 54, 0.4);
      animation: pulseAnim 2s infinite;
    }
    @keyframes pulseAnim {
      0% { box-shadow: 0 0 0 0 rgba(255, 94, 54, 0.6); }
      70% { box-shadow: 0 0 0 10px rgba(255, 94, 54, 0); }
      100% { box-shadow: 0 0 0 0 rgba(255, 94, 54, 0); }
    }
    .hero-title {
      font-size: 2.8rem;
      font-weight: 800;
      line-height: 1.25;
      margin-bottom: 20px;
      color: var(--text-main);
      max-width: 960px;
      margin-left: auto;
      margin-right: auto;
    }
    .hero-title .highlight {
      background: var(--gradient-brand);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
    }
    .hero-subtitle {
      font-size: 1.2rem;
      color: var(--text-muted);
      max-width: 760px;
      margin: 0 auto 36px auto;
      line-height: 1.6;
    }
    .hero-cta-group {
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 16px;
      flex-wrap: wrap;
      margin-bottom: 48px;
    }
    .btn-hero-official {
      padding: 14px 34px;
      font-size: 1.1rem;
      font-weight: 700;
      color: #ffffff;
      background: var(--gradient-brand);
      border-radius: 50px;
      box-shadow: 0 8px 25px rgba(37, 99, 235, 0.35);
      border: 2px solid transparent;
      transform: translateY(0);
      transition: all 0.25s ease;
    }
    .btn-hero-official:hover {
      transform: translateY(-3px);
      box-shadow: 0 12px 30px rgba(37, 99, 235, 0.45);
    }
    .btn-hero-secondary {
      padding: 14px 30px;
      font-size: 1.05rem;
      font-weight: 600;
      color: var(--text-main);
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: 50px;
      box-shadow: var(--shadow-sm);
    }
    .btn-hero-secondary:hover {
      background: #f8fafc;
      border-color: var(--primary);
      color: var(--primary);
    }
    .hero-metrics {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 20px;
      max-width: 1040px;
      margin: 0 auto;
    }
    .metric-card {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      padding: 22px 18px;
      box-shadow: var(--shadow-sm);
      transition: 0.3s;
    }
    .metric-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-md);
      border-color: rgba(37, 99, 235, 0.3);
    }
    .metric-val {
      font-size: 1.8rem;
      font-weight: 800;
      color: var(--primary);
      margin-bottom: 4px;
      background: var(--gradient-brand);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
    }
    .metric-name {
      font-size: 0.9rem;
      color: var(--text-muted);
      font-weight: 500;
    }

    /* 平台标签/模型矩阵 */
    .model-strip {
      background: #ffffff;
      border-top: 1px solid var(--border-color);
      border-bottom: 1px solid var(--border-color);
      padding: 30px 0;
    }
    .model-tags-wrap {
      display: flex;
      flex-wrap: wrap;
      justify-content: center;
      gap: 10px;
    }
    .model-chip {
      background: var(--bg-main);
      border: 1px solid var(--border-color);
      padding: 6px 14px;
      border-radius: 20px;
      font-size: 0.85rem;
      font-weight: 600;
      color: var(--text-muted);
      transition: 0.2s;
    }
    .model-chip:hover {
      color: var(--primary);
      border-color: var(--primary);
      background: #ffffff;
    }

    /* 模块卡片通用 Grid */
    .grid-3 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .grid-4 {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 20px;
    }
    .grid-2 {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 30px;
      align-items: center;
    }
    .feature-card {
      background: var(--bg-card);
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      padding: 28px 24px;
      box-shadow: var(--shadow-sm);
      transition: all 0.3s ease;
      display: flex;
      flex-direction: column;
    }
    .feature-card:hover {
      transform: translateY(-5px);
      box-shadow: var(--shadow-lg);
      border-color: rgba(37, 99, 235, 0.3);
    }
    .feature-icon-box {
      width: 50px;
      height: 50px;
      border-radius: 12px;
      background: linear-gradient(135deg, rgba(37, 99, 235, 0.1), rgba(124, 58, 237, 0.1));
      color: var(--primary);
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 1.4rem;
      font-weight: 700;
      margin-bottom: 18px;
    }
    .feature-card h3 {
      font-size: 1.2rem;
      font-weight: 700;
      margin-bottom: 10px;
      color: var(--text-main);
    }
    .feature-card p {
      font-size: 0.95rem;
      color: var(--text-muted);
      line-height: 1.6;
    }

    /* 流程步骤 */
    .step-list {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 20px;
      position: relative;
    }
    .step-item {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      padding: 24px 20px;
      position: relative;
    }
    .step-num {
      width: 36px;
      height: 36px;
      border-radius: 50%;
      background: var(--gradient-brand);
      color: #ffffff;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 700;
      font-size: 1rem;
      margin-bottom: 14px;
    }
    .step-item h4 {
      font-size: 1.1rem;
      font-weight: 700;
      margin-bottom: 8px;
      color: var(--text-main);
    }
    .step-item p {
      font-size: 0.9rem;
      color: var(--text-muted);
    }

    /* 对比评测版块 */
    .compare-section {
      background: #ffffff;
      border-top: 1px solid var(--border-color);
      border-bottom: 1px solid var(--border-color);
    }
    .score-badge-card {
      background: linear-gradient(135deg, #1e293b 0%, #0f172a 100%);
      color: #ffffff;
      border-radius: var(--radius-lg);
      padding: 30px;
      display: flex;
      align-items: center;
      justify-content: space-between;
      margin-bottom: 30px;
      box-shadow: 0 10px 25px rgba(15, 23, 42, 0.15);
    }
    .score-left h3 {
      font-size: 1.4rem;
      margin-bottom: 6px;
    }
    .score-stars {
      color: #f59e0b;
      font-size: 1.3rem;
      letter-spacing: 2px;
    }
    .score-right {
      text-align: right;
    }
    .score-number {
      font-size: 2.8rem;
      font-weight: 900;
      color: #38bdf8;
      line-height: 1;
    }
    .score-scale {
      font-size: 0.95rem;
      color: #94a3b8;
    }
    .compare-table-wrap {
      overflow-x: auto;
      background: #ffffff;
      border-radius: var(--radius-md);
      border: 1px solid var(--border-color);
      box-shadow: var(--shadow-sm);
    }
    .compare-table {
      width: 100%;
      border-collapse: collapse;
      text-align: left;
      min-width: 680px;
    }
    .compare-table th, .compare-table td {
      padding: 16px 20px;
      border-bottom: 1px solid var(--border-color);
      font-size: 0.95rem;
    }
    .compare-table th {
      background: #f8fafc;
      color: var(--text-main);
      font-weight: 700;
    }
    .compare-table td:nth-child(2) {
      background: rgba(37, 99, 235, 0.03);
      font-weight: 600;
      color: var(--primary);
    }
    .compare-table tr:last-child td {
      border-bottom: none;
    }

    /* 案例中心 & 宣传图片 */
    .gallery-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 16px;
      margin-bottom: 30px;
    }
    .gallery-item {
      border-radius: var(--radius-md);
      overflow: hidden;
      border: 1px solid var(--border-color);
      background: #ffffff;
      box-shadow: var(--shadow-sm);
      transition: 0.3s;
    }
    .gallery-item:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-md);
    }
    .gallery-item img {
      width: 100%;
      height: 190px;
      object-fit: cover;
    }
    .gallery-info {
      padding: 12px 14px;
    }
    .gallery-info h5 {
      font-size: 0.95rem;
      color: var(--text-main);
      font-weight: 600;
    }

    /* 用户评论 */
    .testimonials-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 22px;
    }
    .comment-card {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      padding: 24px;
      box-shadow: var(--shadow-sm);
      display: flex;
      flex-direction: column;
      justify-content: space-between;
    }
    .comment-body {
      font-size: 0.95rem;
      color: var(--text-muted);
      line-height: 1.65;
      margin-bottom: 18px;
    }
    .comment-user {
      display: flex;
      align-items: center;
      gap: 12px;
      border-top: 1px solid #f1f5f9;
      padding-top: 14px;
    }
    .user-avatar-tag {
      width: 40px;
      height: 40px;
      border-radius: 50%;
      background: var(--gradient-brand);
      color: #ffffff;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 700;
      font-size: 0.95rem;
    }
    .user-meta h4 {
      font-size: 0.95rem;
      color: var(--text-main);
      font-weight: 700;
    }
    .user-meta span {
      font-size: 0.8rem;
      color: var(--text-muted);
    }

    /* FAQ 折叠 */
    .faq-container {
      max-width: 860px;
      margin: 0 auto;
    }
    .faq-card {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-sm);
      margin-bottom: 12px;
      overflow: hidden;
      transition: border-color 0.2s;
    }
    .faq-card.active {
      border-color: var(--primary);
    }
    .faq-header {
      padding: 18px 22px;
      font-size: 1.05rem;
      font-weight: 600;
      color: var(--text-main);
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
      background: #ffffff;
    }
    .faq-header:hover {
      color: var(--primary);
    }
    .faq-icon {
      font-size: 1.2rem;
      transition: transform 0.3s;
    }
    .faq-card.active .faq-icon {
      transform: rotate(45deg);
    }
    .faq-content {
      display: none;
      padding: 0 22px 18px 22px;
      font-size: 0.95rem;
      color: var(--text-muted);
      line-height: 1.7;
    }
    .faq-card.active .faq-content {
      display: block;
    }

    /* 表单与需求匹配 */
    .form-box {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-lg);
      padding: 36px;
      box-shadow: var(--shadow-md);
    }
    .form-group {
      margin-bottom: 18px;
    }
    .form-group label {
      display: block;
      font-size: 0.9rem;
      font-weight: 600;
      margin-bottom: 6px;
      color: var(--text-main);
    }
    .form-control {
      width: 100%;
      padding: 12px 14px;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-sm);
      font-size: 0.95rem;
      color: var(--text-main);
      background: #f8fafc;
      transition: 0.2s;
    }
    .form-control:focus {
      outline: none;
      border-color: var(--primary);
      background: #ffffff;
      box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
    }
    .btn-submit {
      width: 100%;
      padding: 14px;
      background: var(--gradient-brand);
      color: #ffffff;
      font-weight: 700;
      font-size: 1.05rem;
      border: none;
      border-radius: var(--radius-sm);
      cursor: pointer;
      transition: opacity 0.2s;
    }
    .btn-submit:hover {
      opacity: 0.92;
    }

    /* 联系我们 & 二维码 */
    .contact-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 30px;
    }
    .contact-info-card {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-lg);
      padding: 32px;
      display: flex;
      flex-direction: column;
      justify-content: space-between;
    }
    .contact-items {
      list-style: none;
      margin: 20px 0;
    }
    .contact-items li {
      margin-bottom: 12px;
      font-size: 0.95rem;
      color: var(--text-muted);
      display: flex;
      align-items: center;
      gap: 8px;
    }
    .contact-items strong {
      color: var(--text-main);
    }
    .qr-container {
      display: flex;
      align-items: center;
      gap: 20px;
      padding: 16px;
      background: #f8fafc;
      border-radius: var(--radius-md);
      border: 1px solid var(--border-color);
    }
    .qr-container img {
      width: 110px;
      height: 110px;
      border-radius: var(--radius-sm);
      border: 1px solid #e2e8f0;
    }

    /* 文章列表 & 友情链接 */
    .article-list {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 20px;
      margin-bottom: 30px;
    }
    .article-card {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      padding: 20px;
      transition: 0.3s;
    }
    .article-card:hover {
      border-color: var(--primary);
      transform: translateY(-3px);
    }
    .article-card a {
      font-size: 1rem;
      font-weight: 600;
      color: var(--text-main);
      display: block;
      margin-bottom: 8px;
    }
    .article-card a:hover {
      color: var(--primary);
    }
    .friend-links-box {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      padding: 20px 24px;
      display: flex;
      flex-wrap: wrap;
      align-items: center;
      gap: 16px;
    }
    .friend-links-box span {
      font-weight: 700;
      color: var(--text-main);
      font-size: 0.9rem;
    }
    .friend-links-box a {
      font-size: 0.9rem;
      color: var(--text-muted);
      padding: 4px 10px;
      background: var(--bg-main);
      border-radius: 4px;
    }
    .friend-links-box a:hover {
      color: var(--primary);
      background: rgba(37, 99, 235, 0.08);
    }

    /* 页脚 */
    .site-footer {
      background: #0f172a;
      color: #94a3b8;
      padding: 50px 0 30px 0;
      border-top: 1px solid #1e293b;
    }
    .footer-top {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr;
      gap: 40px;
      margin-bottom: 36px;
    }
    .footer-brand h4 {
      font-size: 1.3rem;
      color: #ffffff;
      margin-bottom: 12px;
    }
    .footer-brand p {
      font-size: 0.9rem;
      line-height: 1.6;
      max-width: 420px;
    }
    .footer-col h5 {
      font-size: 1rem;
      color: #ffffff;
      margin-bottom: 16px;
      font-weight: 600;
    }
    .footer-col ul {
      list-style: none;
    }
    .footer-col ul li {
      margin-bottom: 8px;
    }
    .footer-col ul a {
      color: #94a3b8;
      font-size: 0.9rem;
    }
    .footer-col ul a:hover {
      color: #38bdf8;
    }
    .footer-bottom {
      border-top: 1px solid #1e293b;
      padding-top: 24px;
      display: flex;
      align-items: center;
      justify-content: space-between;
      font-size: 0.85rem;
      color: #64748b;
    }
    .footer-bottom a {
      color: #94a3b8;
    }

    /* 悬浮工具栏 */
    .float-toolbar {
      position: fixed;
      right: 24px;
      bottom: 30px;
      z-index: 999;
      display: flex;
      flex-direction: column;
      gap: 10px;
    }
    .float-btn {
      width: 46px;
      height: 46px;
      border-radius: 50%;
      background: #ffffff;
      color: var(--text-main);
      box-shadow: 0 4px 15px rgba(0,0,0,0.12);
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 1.2rem;
      border: 1px solid var(--border-color);
      cursor: pointer;
      transition: 0.2s;
    }
    .float-btn:hover {
      background: var(--primary);
      color: #ffffff;
      border-color: var(--primary);
    }

    /* 响应式适配 */
    @media (max-width: 1024px) {
      .grid-3, .testimonials-grid, .article-list {
        grid-template-columns: repeat(2, 1fr);
      }
      .grid-4, .step-list, .gallery-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .hero-metrics {
        grid-template-columns: repeat(2, 1fr);
      }
      .footer-top {
        grid-template-columns: 1fr 1fr;
      }
    }
    @media (max-width: 768px) {
      .nav-links {
        display: none;
        position: absolute;
        top: 72px;
        left: 0;
        right: 0;
        background: #ffffff;
        flex-direction: column;
        padding: 16px 24px;
        border-bottom: 1px solid var(--border-color);
        box-shadow: var(--shadow-md);
      }
      .nav-links.active {
        display: flex;
      }
      .menu-toggle {
        display: block;
      }
      .hero-title {
        font-size: 2rem;
      }
      .section-title {
        font-size: 1.6rem;
      }
      .grid-3, .grid-4, .grid-2, .testimonials-grid, .article-list, .gallery-grid, .step-list, .contact-grid {
        grid-template-columns: 1fr;
      }
      .hero-metrics {
        grid-template-columns: 1fr;
      }
      .score-badge-card {
        flex-direction: column;
        align-items: flex-start;
        gap: 16px;
      }
      .score-right {
        text-align: left;
      }
      .footer-top {
        grid-template-columns: 1fr;
      }
      .footer-bottom {
        flex-direction: column;
        gap: 12px;
        text-align: center;
      }
    }