:root {
      --bg-base: #0a0e1a;
      --bg-surface: #111827;
      --bg-card: rgba(17, 24, 39, 0.7);
      --text-main: #f3f4f6;
      --text-muted: #9ca3af;
      --neon-cyan: #00f0ff;
      --neon-pink: #ff007f;
      --neon-purple: #8b5cf6;
      --neon-green: #10b981;
      --border-glow: rgba(0, 240, 255, 0.25);
      --border-light: rgba(255, 255, 255, 0.08);
      --container-max: 1240px;
      --transition: all 0.25s ease-in-out;
    }

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

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

    body {
      background-color: var(--bg-base);
      background-image: 
        radial-gradient(circle at 10% 10%, rgba(0, 240, 255, 0.08) 0%, transparent 40%),
        radial-gradient(circle at 90% 90%, rgba(255, 0, 127, 0.08) 0%, transparent 40%),
        linear-gradient(rgba(255, 255, 255, 0.02) 1px, transparent 1px),
        linear-gradient(90deg, rgba(255, 255, 255, 0.02) 1px, transparent 1px);
      background-size: 100% 100%, 100% 100%, 48px 48px, 48px 48px;
      min-height: 100vh;
      display: flex;
      flex-direction: column;
    }

    .container {
      width: 100%;
      max-width: var(--container-max);
      margin-left: auto;
      margin-right: auto;
      padding-left: 24px;
      padding-right: 24px;
    }

    a {
      color: inherit;
      text-decoration: none;
      transition: var(--transition);
    }

    /* 顶部导航 */
    .site-header {
      position: sticky;
      top: 0;
      z-index: 100;
      background: rgba(10, 14, 26, 0.85);
      backdrop-filter: blur(12px);
      border-bottom: 1px solid var(--border-glow);
    }
    .nav-wrap {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 72px;
    }
    .brand-box {
      display: flex;
      align-items: center;
      gap: 12px;
    }
    .ai-page-logo {
      height: 40px;
      width: auto;
      display: block;
    }
    .brand-name {
      font-size: 1.35rem;
      font-weight: 700;
      letter-spacing: 0.5px;
      background: linear-gradient(90deg, #fff, var(--neon-cyan));
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
    }
    .nav-links {
      display: flex;
      align-items: center;
      gap: 0;
      list-style: none;
    }
    .nav-links li a {
      font-size: 0.95rem;
      color: #d1d5db;
      padding: 8px 12px;
      border-radius: 6px;
    }
    .nav-links li a:hover {
      color: var(--neon-cyan);
      background: rgba(0, 240, 255, 0.06);
    }
    .nav-actions {
      display: flex;
      align-items: center;
      gap: 12px;
    }
    .mobile-menu-btn {
      display: none;
      background: none;
      border: 1px solid var(--border-glow);
      color: var(--text-main);
      padding: 6px 10px;
      border-radius: 6px;
      font-size: 1rem;
      cursor: pointer;
    }

    /* 按钮通用 */
    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      font-weight: 600;
      font-size: 0.95rem;
      padding: 10px 20px;
      border-radius: 6px;
      cursor: pointer;
      border: 1px solid transparent;
      transition: var(--transition);
      white-space: nowrap;
    }
    .btn-neon-primary {
      background: linear-gradient(135deg, var(--neon-cyan), #00a3ff);
      color: #040914;
      box-shadow: 0 0 16px rgba(0, 240, 255, 0.4);
    }
    .btn-neon-primary:hover {
      box-shadow: 0 0 24px rgba(0, 240, 255, 0.7);
      transform: translateY(-2px);
    }
    .btn-neon-secondary {
      background: rgba(255, 255, 255, 0.05);
      color: var(--text-main);
      border-color: var(--border-glow);
    }
    .btn-neon-secondary:hover {
      border-color: var(--neon-pink);
      color: #fff;
      box-shadow: 0 0 14px rgba(255, 0, 127, 0.3);
      transform: translateY(-2px);
    }

    /* 页面各模块结构 */
    .section-pad {
      padding: 72px 0;
      position: relative;
    }
    .section-head {
      text-align: center;
      margin-bottom: 48px;
    }
    .section-badge {
      display: inline-block;
      padding: 4px 12px;
      background: rgba(0, 240, 255, 0.1);
      border: 1px solid var(--neon-cyan);
      color: var(--neon-cyan);
      border-radius: 20px;
      font-size: 0.8rem;
      margin-bottom: 12px;
      text-transform: uppercase;
      letter-spacing: 1px;
    }
    .section-title {
      font-size: 2rem;
      font-weight: 700;
      color: #ffffff;
      margin-bottom: 12px;
    }
    .section-desc {
      color: var(--text-muted);
      max-width: 680px;
      margin: 0 auto;
      font-size: 0.95rem;
    }

    /* 首屏无图 Hero */
    .hero-box {
      padding: 96px 0 72px;
      text-align: center;
      position: relative;
    }
    .hero-tagline {
      display: inline-flex;
      align-items: center;
      gap: 8px;
      background: rgba(255, 0, 127, 0.1);
      border: 1px solid var(--neon-pink);
      color: #ff77b4;
      padding: 6px 16px;
      border-radius: 30px;
      font-size: 0.85rem;
      margin-bottom: 24px;
    }
    .hero-h1 {
      font-size: 2.6rem;
      font-weight: 800;
      line-height: 1.25;
      max-width: 860px;
      margin: 0 auto 20px;
      background: linear-gradient(135deg, #ffffff 40%, var(--neon-cyan) 80%, var(--neon-pink) 100%);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
    }
    .hero-p {
      font-size: 1.1rem;
      color: #d1d5db;
      max-width: 720px;
      margin: 0 auto 32px;
    }
    .hero-btns {
      display: flex;
      justify-content: center;
      gap: 16px;
      margin-bottom: 48px;
      flex-wrap: wrap;
    }
    .hero-metrics {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 16px;
      margin-top: 24px;
    }
    .metric-card {
      background: var(--bg-card);
      border: 1px solid var(--border-light);
      border-radius: 12px;
      padding: 20px;
      backdrop-filter: blur(8px);
      transition: var(--transition);
    }
    .metric-card:hover {
      border-color: var(--neon-cyan);
      box-shadow: 0 0 20px rgba(0, 240, 255, 0.2);
      transform: translateY(-3px);
    }
    .metric-num {
      font-size: 1.8rem;
      font-weight: 700;
      color: var(--neon-cyan);
      margin-bottom: 4px;
    }
    .metric-label {
      font-size: 0.85rem;
      color: var(--text-muted);
    }

    /* 通用网格卡片 */
    .grid-3 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 20px;
    }
    .grid-2 {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 24px;
    }
    .grid-4 {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 16px;
    }

    .service-card {
      background: var(--bg-surface);
      border: 1px solid var(--border-light);
      border-radius: 12px;
      padding: 24px;
      transition: var(--transition);
      display: flex;
      flex-direction: column;
      justify-content: space-between;
    }
    .service-card:hover {
      border-color: var(--neon-purple);
      box-shadow: 0 0 20px rgba(139, 92, 246, 0.25);
      transform: translateY(-4px);
    }
    .service-icon {
      width: 44px;
      height: 44px;
      border-radius: 8px;
      background: rgba(0, 240, 255, 0.1);
      color: var(--neon-cyan);
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 1.25rem;
      margin-bottom: 16px;
    }
    .service-card h3 {
      font-size: 1.15rem;
      margin-bottom: 10px;
      color: #fff;
    }
    .service-card p {
      font-size: 0.9rem;
      color: var(--text-muted);
      line-height: 1.6;
    }

    /* 平台矩阵与模型支持标签 */
    .models-stream {
      display: flex;
      flex-wrap: wrap;
      gap: 10px;
      justify-content: center;
      margin-top: 24px;
    }
    .model-chip {
      background: rgba(255, 255, 255, 0.04);
      border: 1px solid rgba(255, 255, 255, 0.1);
      padding: 6px 14px;
      border-radius: 6px;
      font-size: 0.85rem;
      color: #d1d5db;
      transition: var(--transition);
    }
    .model-chip:hover {
      border-color: var(--neon-cyan);
      color: var(--neon-cyan);
    }

    /* 流程步骤 */
    .flow-steps {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 20px;
      position: relative;
    }
    .flow-card {
      background: var(--bg-surface);
      border: 1px solid var(--border-light);
      border-radius: 12px;
      padding: 24px;
      position: relative;
    }
    .flow-index {
      font-size: 1.5rem;
      font-weight: 800;
      color: var(--neon-pink);
      margin-bottom: 8px;
    }
    .flow-card h3 {
      font-size: 1.1rem;
      color: #fff;
      margin-bottom: 8px;
    }
    .flow-card p {
      font-size: 0.88rem;
      color: var(--text-muted);
    }

    /* 对比表格 */
    .table-container {
      overflow-x: auto;
      border: 1px solid var(--border-light);
      border-radius: 12px;
      background: var(--bg-surface);
    }
    .compare-table {
      width: 100%;
      border-collapse: collapse;
      text-align: left;
      font-size: 0.95rem;
    }
    .compare-table th, .compare-table td {
      padding: 16px 20px;
      border-bottom: 1px solid rgba(255, 255, 255, 0.06);
    }
    .compare-table th {
      background: rgba(255, 255, 255, 0.03);
      color: #ffffff;
    }
    .compare-table tr:hover td {
      background: rgba(0, 240, 255, 0.03);
    }
    .text-highlight {
      color: var(--neon-cyan);
      font-weight: 600;
    }

    /* 案例展示 */
    .case-card {
      background: var(--bg-surface);
      border: 1px solid var(--border-light);
      border-radius: 12px;
      overflow: hidden;
      transition: var(--transition);
    }
    .case-card:hover {
      border-color: var(--neon-cyan);
      transform: translateY(-4px);
    }
    .case-img-box {
      width: 100%;
      aspect-ratio: 16 / 9;
      overflow: hidden;
      background: #1f2937;
    }
    .case-img-box.square {
      aspect-ratio: 1 / 1;
    }
    .case-img-box img {
      width: 100%;
      height: 100%;
      object-fit: cover;
      display: block;
      transition: transform 0.3s ease;
    }
    .case-card:hover .case-img-box img {
      transform: scale(1.04);
    }
    .case-info {
      padding: 20px;
    }
    .case-info h3 {
      font-size: 1.1rem;
      margin-bottom: 8px;
      color: #fff;
    }
    .case-info p {
      font-size: 0.88rem;
      color: var(--text-muted);
    }

    /* 用户评论卡片 */
    .testimonial-card {
      background: var(--bg-surface);
      border: 1px solid var(--border-light);
      border-radius: 12px;
      padding: 22px;
      display: flex;
      flex-direction: column;
      justify-content: space-between;
    }
    .testimonial-text {
      font-size: 0.9rem;
      color: #d1d5db;
      margin-bottom: 16px;
      line-height: 1.6;
    }
    .testimonial-user {
      display: flex;
      align-items: center;
      gap: 12px;
      border-top: 1px solid rgba(255, 255, 255, 0.06);
      padding-top: 12px;
    }
    .user-avatar {
      width: 36px;
      height: 36px;
      border-radius: 50%;
      background: linear-gradient(135deg, var(--neon-purple), var(--neon-cyan));
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 700;
      color: #fff;
      font-size: 0.85rem;
    }
    .user-role {
      font-size: 0.8rem;
      color: var(--text-muted);
    }

    /* FAQ 手风琴 */
    .faq-list {
      max-width: 860px;
      margin: 0 auto;
      display: flex;
      flex-direction: column;
      gap: 12px;
    }
    .faq-item {
      border: 1px solid var(--border-light);
      background: var(--bg-surface);
      border-radius: 8px;
      overflow: hidden;
      transition: var(--transition);
    }
    .faq-item.active {
      border-color: var(--neon-cyan);
    }
    .faq-question {
      padding: 18px 24px;
      cursor: pointer;
      display: flex;
      align-items: center;
      justify-content: space-between;
      font-weight: 600;
      color: #fff;
    }
    .faq-icon {
      font-size: 1.1rem;
      transition: transform 0.25s ease;
      color: var(--neon-cyan);
    }
    .faq-item.active .faq-icon {
      transform: rotate(45deg);
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease-out;
      padding: 0 24px;
      color: var(--text-muted);
      font-size: 0.92rem;
      line-height: 1.6;
    }
    .faq-item.active .faq-answer {
      padding-bottom: 20px;
    }

    /* 表单区域 */
    .contact-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 32px;
      background: var(--bg-surface);
      border: 1px solid var(--border-light);
      border-radius: 16px;
      padding: 40px;
    }
    .form-group {
      margin-bottom: 18px;
    }
    .form-label {
      display: block;
      font-size: 0.88rem;
      color: #e5e7eb;
      margin-bottom: 8px;
    }
    .form-control {
      width: 100%;
      background: #0a0e1a;
      border: 1px solid var(--border-light);
      border-radius: 6px;
      padding: 12px 16px;
      color: #fff;
      font-size: 0.92rem;
      transition: var(--transition);
    }
    .form-control:focus {
      outline: none;
      border-color: var(--neon-cyan);
      box-shadow: 0 0 10px rgba(0, 240, 255, 0.3);
    }
    textarea.form-control {
      resize: vertical;
      min-height: 100px;
    }

    /* 资讯列表 */
    .articles-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 20px;
    }
    .article-item {
      background: var(--bg-surface);
      border: 1px solid var(--border-light);
      padding: 20px;
      border-radius: 10px;
      transition: var(--transition);
      display: flex;
      flex-direction: column;
      justify-content: space-between;
    }
    .article-item:hover {
      border-color: var(--neon-cyan);
      transform: translateY(-3px);
    }
    .article-title {
      font-size: 1rem;
      font-weight: 600;
      color: #fff;
      margin-bottom: 10px;
    }
    .article-link {
      font-size: 0.85rem;
      color: var(--neon-cyan);
      display: inline-flex;
      align-items: center;
      gap: 4px;
    }

    /* 页脚 */
    .site-footer {
      background: #070a12;
      border-top: 1px solid var(--border-light);
      padding: 60px 0 32px;
      margin-top: auto;
      font-size: 0.9rem;
      color: var(--text-muted);
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1.2fr;
      gap: 36px;
      margin-bottom: 40px;
    }
    .footer-col h4 {
      color: #fff;
      font-size: 1rem;
      margin-bottom: 16px;
    }
    .footer-links {
      list-style: none;
      display: flex;
      flex-direction: column;
      gap: 8px;
    }
    .footer-links a:hover {
      color: var(--neon-cyan);
    }
    .footer-bottom {
      border-top: 1px solid rgba(255, 255, 255, 0.05);
      padding-top: 24px;
      display: flex;
      justify-content: space-between;
      align-items: center;
      flex-wrap: wrap;
      gap: 16px;
    }
    .friend-links-box {
      margin-bottom: 24px;
      padding-bottom: 24px;
      border-bottom: 1px solid rgba(255, 255, 255, 0.05);
    }
    .friend-links-box h5 {
      color: #9ca3af;
      margin-bottom: 12px;
      font-size: 0.85rem;
    }
    .friend-links-list {
      display: flex;
      flex-wrap: wrap;
      gap: 16px;
    }
    .friend-links-list a {
      color: #6b7280;
      font-size: 0.85rem;
    }
    .friend-links-list a:hover {
      color: var(--neon-cyan);
    }

    /* 浮动组件 */
    .float-panel {
      position: fixed;
      right: 24px;
      bottom: 24px;
      z-index: 99;
      display: flex;
      flex-direction: column;
      gap: 10px;
    }
    .float-btn {
      width: 44px;
      height: 44px;
      border-radius: 50%;
      background: var(--bg-surface);
      border: 1px solid var(--border-glow);
      color: #fff;
      display: flex;
      align-items: center;
      justify-content: center;
      box-shadow: 0 4px 12px rgba(0, 0, 0, 0.4);
      cursor: pointer;
      position: relative;
    }
    .float-btn:hover {
      border-color: var(--neon-cyan);
      box-shadow: 0 0 12px var(--neon-cyan);
    }
    .qr-popup {
      position: absolute;
      right: 54px;
      bottom: 0;
      background: #111827;
      border: 1px solid var(--border-glow);
      padding: 12px;
      border-radius: 8px;
      display: none;
      box-shadow: 0 8px 24px rgba(0,0,0,0.5);
      width: 140px;
      text-align: center;
    }
    .qr-popup img {
      width: 100%;
      height: auto;
      border-radius: 4px;
      display: block;
    }
    .qr-popup p {
      font-size: 0.75rem;
      margin-top: 6px;
      color: #d1d5db;
    }
    .float-btn:hover .qr-popup {
      display: block;
    }

    /* 响应式断点 */
    @media (max-width: 992px) {
      .hero-h1 { font-size: 2.1rem; }
      .grid-3 { grid-template-columns: repeat(2, 1fr); }
      .grid-4, .hero-metrics, .flow-steps { grid-template-columns: repeat(2, 1fr); }
      .contact-grid { grid-template-columns: 1fr; }
      .footer-grid { grid-template-columns: 1fr 1fr; }
      .articles-grid { grid-template-columns: 1fr; }
      .nav-links { display: none; }
      .mobile-menu-btn { display: block; }
      .nav-links.show {
        display: flex;
        flex-direction: column;
        position: absolute;
        top: 72px;
        left: 0;
        right: 0;
        background: #0a0e1a;
        padding: 20px;
        border-bottom: 1px solid var(--border-glow);
      }
    }

    @media (max-width: 640px) {
      .hero-h1 { font-size: 1.7rem; }
      .grid-3, .grid-2, .grid-4, .hero-metrics, .flow-steps { grid-template-columns: 1fr; }
      .footer-grid { grid-template-columns: 1fr; }
      .section-pad { padding: 48px 0; }
    }