:root {
      --bg-base: #f8fafc;
      --bg-surface: #ffffff;
      --bg-card: rgba(255, 255, 255, 0.95);
      --text-main: #0f172a;
      --text-sub: #475569;
      --text-muted: #64748b;
      --neon-cyan: #06b6d4;
      --neon-purple: #8b5cf6;
      --neon-pink: #ec4899;
      --border-color: #e2e8f0;
      --border-glow: rgba(139, 92, 246, 0.25);
      --shadow-sm: 0 2px 4px rgba(0,0,0,0.04);
      --shadow-md: 0 10px 25px -5px rgba(139, 92, 246, 0.08), 0 8px 10px -6px rgba(6, 182, 212, 0.08);
      --shadow-hover: 0 20px 30px -10px rgba(139, 92, 246, 0.15), 0 10px 15px -3px rgba(6, 182, 212, 0.12);
      --radius-sm: 8px;
      --radius-md: 14px;
      --radius-lg: 20px;
      --max-width: 1200px;
    }

    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
      -webkit-tap-highlight-color: transparent;
    }

    body {
      font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
      background-color: var(--bg-base);
      color: var(--text-main);
      line-height: 1.6;
      background-image: 
        radial-gradient(circle at 10% 0%, rgba(6, 182, 212, 0.06) 0%, transparent 40%),
        radial-gradient(circle at 90% 20%, rgba(236, 72, 153, 0.05) 0%, transparent 40%),
        radial-gradient(circle at 50% 80%, rgba(139, 92, 246, 0.05) 0%, transparent 50%);
      background-attachment: fixed;
      overflow-x: hidden;
    }

    a {
      color: inherit;
      text-decoration: none;
      transition: all 0.25s ease;
    }

    .container {
      width: 100%;
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 20px;
    }

    /* 顶部导航 */
    header.site-header {
      position: sticky;
      top: 0;
      z-index: 1000;
      background: rgba(255, 255, 255, 0.9);
      backdrop-filter: blur(12px);
      border-bottom: 1px solid var(--border-color);
      box-shadow: 0 2px 10px rgba(0,0,0,0.03);
    }
    .nav-wrapper {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 72px;
    }
    .brand-area {
      display: flex;
      align-items: center;
      gap: 12px;
    }
    .brand-area .ai-page-logo {
      height: 38px;
      width: auto;
      display: block;
    }
    .brand-title {
      font-size: 1.25rem;
      font-weight: 700;
      background: linear-gradient(135deg, #0284c7, #7c3aed);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
    }
    .nav-menu {
      display: flex;
      align-items: center;
    }
    .nav-links {
      display: flex;
      gap: 0;
      list-style: none;
      align-items: center;
    }
    .nav-links li a {
      font-size: 0.95rem;
      font-weight: 500;
      color: var(--text-sub);
      padding: 8px 12px;
      border-radius: var(--radius-sm);
    }
    .nav-links li a:hover {
      color: var(--neon-purple);
      background: rgba(139, 92, 246, 0.08);
    }
    .nav-cta {
      display: flex;
      align-items: center;
      gap: 10px;
      margin-left: 16px;
    }
    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 9px 20px;
      font-size: 0.95rem;
      font-weight: 600;
      border-radius: 9999px;
      cursor: pointer;
      border: 1px solid transparent;
      transition: all 0.25s ease;
      white-space: nowrap;
    }
    .btn-primary {
      background: linear-gradient(135deg, #06b6d4, #8b5cf6);
      color: #ffffff;
      box-shadow: 0 4px 14px rgba(139, 92, 246, 0.35);
    }
    .btn-primary:hover {
      opacity: 0.95;
      transform: translateY(-1px);
      box-shadow: 0 6px 20px rgba(139, 92, 246, 0.45);
    }
    .btn-outline {
      background: #ffffff;
      color: var(--neon-purple);
      border-color: rgba(139, 92, 246, 0.4);
    }
    .btn-outline:hover {
      background: rgba(139, 92, 246, 0.05);
      border-color: var(--neon-purple);
    }
    .menu-toggle {
      display: none;
      background: none;
      border: none;
      font-size: 1.5rem;
      color: var(--text-main);
      cursor: pointer;
    }

    /* 区域通用规范 */
    section {
      padding: 70px 0;
      position: relative;
    }
    .section-header {
      text-align: center;
      max-width: 760px;
      margin: 0 auto 48px auto;
    }
    .section-tag {
      display: inline-block;
      padding: 4px 14px;
      font-size: 0.85rem;
      font-weight: 600;
      color: var(--neon-purple);
      background: rgba(139, 92, 246, 0.1);
      border: 1px solid rgba(139, 92, 246, 0.25);
      border-radius: 9999px;
      margin-bottom: 12px;
      text-transform: uppercase;
      letter-spacing: 0.5px;
    }
    .section-title {
      font-size: 2.1rem;
      font-weight: 800;
      color: var(--text-main);
      margin-bottom: 14px;
      letter-spacing: -0.5px;
    }
    .section-desc {
      font-size: 1.05rem;
      color: var(--text-sub);
    }

    /* Hero 首屏 (无图规范) */
    .hero-section {
      padding: 80px 0 70px 0;
      text-align: center;
      position: relative;
    }
    .hero-glow-1 {
      position: absolute;
      top: -10%;
      left: 20%;
      width: 320px;
      height: 320px;
      background: radial-gradient(circle, rgba(6, 182, 212, 0.18), transparent 70%);
      filter: blur(40px);
      z-index: -1;
      pointer-events: none;
    }
    .hero-glow-2 {
      position: absolute;
      top: 10%;
      right: 20%;
      width: 360px;
      height: 360px;
      background: radial-gradient(circle, rgba(236, 72, 153, 0.15), transparent 70%);
      filter: blur(50px);
      z-index: -1;
      pointer-events: none;
    }
    .hero-content {
      max-width: 880px;
      margin: 0 auto;
    }
    .hero-title {
      font-size: 2.75rem;
      font-weight: 900;
      line-height: 1.25;
      color: var(--text-main);
      margin-bottom: 20px;
      letter-spacing: -1px;
    }
    .hero-highlight {
      background: linear-gradient(120deg, #06b6d4, #8b5cf6, #ec4899);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      display: inline-block;
    }
    .hero-desc {
      font-size: 1.18rem;
      color: var(--text-sub);
      margin-bottom: 36px;
      line-height: 1.7;
    }
    .hero-actions {
      display: flex;
      gap: 16px;
      justify-content: center;
      margin-bottom: 48px;
      flex-wrap: wrap;
    }
    .hero-actions .btn-lg {
      padding: 14px 34px;
      font-size: 1.05rem;
    }

    /* 统计卡片 */
    .stats-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 20px;
      margin-top: 10px;
    }
    .stat-card {
      background: var(--bg-surface);
      border: 1px solid var(--border-color);
      padding: 24px 16px;
      border-radius: var(--radius-md);
      box-shadow: var(--shadow-sm);
      text-align: center;
      transition: all 0.3s ease;
    }
    .stat-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-md);
      border-color: var(--border-glow);
    }
    .stat-num {
      font-size: 2rem;
      font-weight: 800;
      color: #7c3aed;
      margin-bottom: 4px;
    }
    .stat-label {
      font-size: 0.9rem;
      color: var(--text-muted);
      font-weight: 500;
    }

    /* 通用网格与卡片 */
    .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: 28px;
    }
    .feature-card {
      background: var(--bg-card);
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      padding: 26px;
      box-shadow: var(--shadow-sm);
      transition: all 0.3s ease;
      display: flex;
      flex-direction: column;
      justify-content: space-between;
    }
    .feature-card:hover {
      transform: translateY(-5px);
      box-shadow: var(--shadow-hover);
      border-color: rgba(139, 92, 246, 0.4);
    }
    .card-badge {
      display: inline-block;
      font-size: 0.75rem;
      font-weight: 700;
      padding: 3px 10px;
      border-radius: 6px;
      background: rgba(6, 182, 212, 0.1);
      color: #0891b2;
      margin-bottom: 12px;
      align-self: flex-start;
    }
    .card-title {
      font-size: 1.2rem;
      font-weight: 700;
      color: var(--text-main);
      margin-bottom: 10px;
    }
    .card-desc {
      font-size: 0.93rem;
      color: var(--text-sub);
      line-height: 1.6;
    }

    /* 模型支持标签云 */
    .model-tags-wrap {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-lg);
      padding: 32px;
      box-shadow: var(--shadow-sm);
    }
    .tags-container {
      display: flex;
      flex-wrap: wrap;
      gap: 10px;
      justify-content: center;
    }
    .model-tag {
      padding: 7px 16px;
      font-size: 0.88rem;
      font-weight: 600;
      background: #f1f5f9;
      color: #334155;
      border-radius: 9999px;
      border: 1px solid #e2e8f0;
      transition: all 0.2s ease;
    }
    .model-tag:hover {
      background: linear-gradient(135deg, rgba(6, 182, 212, 0.15), rgba(139, 92, 246, 0.15));
      color: var(--neon-purple);
      border-color: var(--neon-purple);
      transform: scale(1.04);
    }

    /* 标准流程时间线 */
    .flow-steps {
      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;
      text-align: center;
      box-shadow: var(--shadow-sm);
      position: relative;
    }
    .step-number {
      width: 44px;
      height: 44px;
      line-height: 44px;
      border-radius: 50%;
      background: linear-gradient(135deg, var(--neon-cyan), var(--neon-purple));
      color: #ffffff;
      font-weight: 800;
      font-size: 1.1rem;
      margin: 0 auto 16px auto;
      box-shadow: 0 4px 10px rgba(139, 92, 246, 0.3);
    }

    /* 案例展示区（图文） */
    .case-card {
      background: #ffffff;
      border-radius: var(--radius-md);
      border: 1px solid var(--border-color);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
      transition: all 0.3s ease;
    }
    .case-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-md);
    }
    .case-media {
      width: 100%;
      height: 200px;
      overflow: hidden;
      background: #e2e8f0;
    }
    .case-media img {
      width: 100%;
      height: 100%;
      object-fit: cover;
      display: block;
      transition: transform 0.4s ease;
    }
    .case-card:hover .case-media img {
      transform: scale(1.05);
    }
    .case-body {
      padding: 20px;
    }

    /* 评测对比表格 */
    .score-banner {
      background: linear-gradient(135deg, rgba(6, 182, 212, 0.08), rgba(139, 92, 246, 0.12));
      border: 1px solid var(--border-glow);
      border-radius: var(--radius-lg);
      padding: 30px;
      margin-bottom: 30px;
      display: flex;
      align-items: center;
      justify-content: space-around;
      flex-wrap: wrap;
      gap: 20px;
      text-align: center;
    }
    .score-badge {
      font-size: 2.4rem;
      font-weight: 900;
      color: #7c3aed;
    }
    .table-container {
      background: #ffffff;
      border-radius: var(--radius-lg);
      border: 1px solid var(--border-color);
      overflow-x: auto;
      box-shadow: var(--shadow-sm);
    }
    .compare-table {
      width: 100%;
      border-collapse: collapse;
      text-align: left;
    }
    .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;
      font-weight: 700;
      color: var(--text-main);
    }
    .compare-table tr:last-child td {
      border-bottom: none;
    }
    .highlight-col {
      background: rgba(139, 92, 246, 0.03);
      font-weight: 600;
      color: #7c3aed;
    }

    /* 用户评论 */
    .testimonial-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;
    }
    .testimonial-user {
      display: flex;
      align-items: center;
      gap: 12px;
      margin-top: 18px;
    }
    .avatar-placeholder {
      width: 44px;
      height: 44px;
      border-radius: 50%;
      background: linear-gradient(135deg, #06b6d4, #8b5cf6);
      color: #ffffff;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 700;
    }

    /* FAQ 折叠面板 */
    .faq-container {
      max-width: 860px;
      margin: 0 auto;
      display: flex;
      flex-direction: column;
      gap: 14px;
    }
    .faq-item {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
    }
    .faq-question {
      padding: 18px 24px;
      font-weight: 600;
      font-size: 1.05rem;
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
      user-select: none;
    }
    .faq-question:hover {
      color: var(--neon-purple);
    }
    .faq-icon {
      font-size: 1.2rem;
      transition: transform 0.3s ease;
      color: var(--neon-purple);
    }
    .faq-item.active .faq-icon {
      transform: rotate(45deg);
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s ease, padding 0.35s ease;
      padding: 0 24px;
      color: var(--text-sub);
      font-size: 0.95rem;
      line-height: 1.6;
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      padding: 0 24px 20px 24px;
    }

    /* 资讯与百科文章 */
    .article-links-wrap {
      display: flex;
      flex-wrap: wrap;
      gap: 12px;
      margin-top: 20px;
    }
    .article-item {
      padding: 10px 18px;
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-sm);
      font-size: 0.9rem;
      color: var(--text-sub);
      transition: all 0.2s ease;
    }
    .article-item:hover {
      border-color: var(--neon-purple);
      color: var(--neon-purple);
      box-shadow: var(--shadow-sm);
    }

    /* 表单与联系区 */
    .contact-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 36px;
      align-items: flex-start;
    }
    .contact-info-panel {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-lg);
      padding: 36px;
      box-shadow: var(--shadow-sm);
    }
    .qr-container {
      margin-top: 24px;
      padding: 16px;
      background: #f8fafc;
      border-radius: var(--radius-md);
      display: inline-flex;
      flex-direction: column;
      align-items: center;
      gap: 8px;
      border: 1px solid var(--border-color);
    }
    .qr-container img {
      width: 140px;
      height: 140px;
      display: block;
      border-radius: 4px;
    }
    .form-panel {
      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;
      color: var(--text-main);
      margin-bottom: 6px;
    }
    .form-control {
      width: 100%;
      padding: 11px 14px;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-sm);
      font-size: 0.95rem;
      color: var(--text-main);
      background: #fdfdfd;
      outline: none;
      transition: border-color 0.2s ease, box-shadow 0.2s ease;
    }
    .form-control:focus {
      border-color: var(--neon-purple);
      box-shadow: 0 0 0 3px rgba(139, 92, 246, 0.15);
    }
    textarea.form-control {
      min-height: 100px;
      resize: vertical;
    }

    /* 友情链接与页脚 */
    .friend-links {
      display: flex;
      flex-wrap: wrap;
      gap: 12px;
      align-items: center;
      padding: 24px 0;
      border-top: 1px solid var(--border-color);
      border-bottom: 1px solid var(--border-color);
      margin-bottom: 28px;
    }
    .friend-links a {
      font-size: 0.88rem;
      color: var(--text-muted);
      padding: 4px 8px;
    }
    .friend-links a:hover {
      color: var(--neon-purple);
    }
    footer.site-footer {
      background: #ffffff;
      border-top: 1px solid var(--border-color);
      padding: 40px 0 24px 0;
      color: var(--text-sub);
    }
    .footer-content {
      display: flex;
      justify-content: space-between;
      align-items: center;
      flex-wrap: wrap;
      gap: 16px;
      font-size: 0.9rem;
    }

    /* 浮动客服 */
    .floating-widget {
      position: fixed;
      right: 24px;
      bottom: 24px;
      z-index: 999;
      display: flex;
      flex-direction: column;
      gap: 10px;
    }
    .float-btn {
      width: 48px;
      height: 48px;
      border-radius: 50%;
      background: linear-gradient(135deg, #06b6d4, #8b5cf6);
      color: #ffffff;
      display: flex;
      align-items: center;
      justify-content: center;
      box-shadow: 0 4px 12px rgba(0,0,0,0.15);
      cursor: pointer;
      border: none;
      font-size: 1.2rem;
      transition: transform 0.2s ease;
    }
    .float-btn:hover {
      transform: scale(1.1);
    }

    /* 响应式调整 */
    @media (max-width: 992px) {
      .grid-4, .stats-grid, .flow-steps {
        grid-template-columns: repeat(2, 1fr);
      }
      .grid-3 {
        grid-template-columns: repeat(2, 1fr);
      }
      .contact-grid {
        grid-template-columns: 1fr;
      }
    }
    @media (max-width: 768px) {
      .menu-toggle {
        display: block;
      }
      .nav-menu {
        position: absolute;
        top: 72px;
        left: 0;
        width: 100%;
        background: #ffffff;
        flex-direction: column;
        align-items: flex-start;
        padding: 20px;
        box-shadow: 0 10px 20px rgba(0,0,0,0.05);
        display: none;
        border-bottom: 1px solid var(--border-color);
      }
      .nav-menu.active {
        display: flex;
      }
      .nav-links {
        flex-direction: column;
        width: 100%;
        align-items: flex-start;
      }
      .nav-links li {
        width: 100%;
      }
      .nav-links li a {
        display: block;
        padding: 10px 0;
      }
      .nav-cta {
        margin-left: 0;
        margin-top: 14px;
        width: 100%;
        justify-content: flex-start;
      }
      .hero-title {
        font-size: 2rem;
      }
      .grid-3, .grid-4, .stats-grid, .flow-steps, .grid-2 {
        grid-template-columns: 1fr;
      }
      .score-banner {
        flex-direction: column;
      }
    }