:root {
      --primary: #7928ca;
      --primary-light: #9f5bf0;
      --primary-dark: #5b1a99;
      --accent: #ff0080;
      --bg-main: #fbfaff;
      --bg-surface: #ffffff;
      --bg-subtle: #f3effe;
      --text-main: #1f1b2d;
      --text-muted: #5e5a73;
      --border-color: #e5def6;
      --shadow-sm: 0 4px 12px rgba(121, 40, 202, 0.06);
      --shadow-md: 0 10px 30px rgba(121, 40, 202, 0.1);
      --shadow-lg: 0 20px 45px rgba(121, 40, 202, 0.16);
      --radius: 14px;
      --transition: all 0.28s ease;
    }

    * {
      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: 1.65;
      overflow-x: hidden;
      background-image: 
        radial-gradient(circle at 10% 0%, rgba(121, 40, 202, 0.05) 0%, transparent 40%),
        radial-gradient(circle at 90% 20%, rgba(255, 0, 128, 0.04) 0%, transparent 40%),
        radial-gradient(circle at 50% 80%, rgba(121, 40, 202, 0.03) 0%, transparent 50%);
      background-attachment: fixed;
    }

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

    .container {
      width: 100%;
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
    }

    /* 顶部导航 */
    .header-nav {
      position: sticky;
      top: 0;
      z-index: 1000;
      background: rgba(255, 255, 255, 0.92);
      backdrop-filter: blur(12px);
      -webkit-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: 76px;
    }

    .brand-box {
      display: flex;
      align-items: center;
      gap: 12px;
    }

    .brand-box .ai-page-logo {
      height: 40px;
      width: auto;
      display: block;
    }

    .brand-name {
      font-size: 1.35rem;
      font-weight: 700;
      background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      letter-spacing: -0.5px;
    }

    .nav-links {
      display: flex;
      align-items: center;
      gap: 0;
      list-style: none;
    }

    .nav-links li a {
      display: inline-block;
      padding: 8px 14px;
      font-size: 0.95rem;
      font-weight: 500;
      color: var(--text-main);
      border-radius: 8px;
    }

    .nav-links li a:hover,
    .nav-links li a.active {
      color: var(--primary);
      background: var(--bg-subtle);
    }

    .nav-actions {
      display: flex;
      align-items: center;
      gap: 12px;
    }

    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 10px 22px;
      border-radius: 50px;
      font-size: 0.95rem;
      font-weight: 600;
      cursor: pointer;
      border: 1px solid transparent;
      transition: var(--transition);
      text-align: center;
      white-space: nowrap;
    }

    .btn-primary {
      background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
      color: #ffffff !important;
      box-shadow: 0 6px 18px rgba(121, 40, 202, 0.28);
    }

    .btn-primary:hover {
      transform: translateY(-2px);
      box-shadow: 0 8px 24px rgba(121, 40, 202, 0.38);
      color: #ffffff !important;
    }

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

    .btn-outline:hover {
      background: var(--primary);
      color: #ffffff;
      transform: translateY(-2px);
    }

    .mobile-menu-toggle {
      display: none;
      background: none;
      border: none;
      font-size: 1.5rem;
      color: var(--text-main);
      cursor: pointer;
      padding: 4px;
    }

    /* 首屏 Hero 无图片 Pure CSS */
    .hero-section {
      padding: 80px 0 60px;
      position: relative;
      text-align: center;
      overflow: hidden;
    }

    .hero-badge {
      display: inline-flex;
      align-items: center;
      gap: 8px;
      padding: 6px 18px;
      background: var(--bg-subtle);
      border: 1px solid var(--border-color);
      border-radius: 30px;
      font-size: 0.88rem;
      font-weight: 600;
      color: var(--primary);
      margin-bottom: 24px;
    }

    .hero-badge span {
      display: inline-block;
      width: 8px;
      height: 8px;
      border-radius: 50%;
      background: var(--accent);
      animation: pulseDot 1.8s infinite;
    }

    @keyframes pulseDot {
      0% { transform: scale(0.9); opacity: 0.7; }
      50% { transform: scale(1.3); opacity: 1; }
      100% { transform: scale(0.9); opacity: 0.7; }
    }

    .hero-title {
      font-size: 2.75rem;
      font-weight: 800;
      line-height: 1.25;
      color: var(--text-main);
      margin-bottom: 20px;
      letter-spacing: -0.5px;
    }

    .hero-title .highlight {
      background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
    }

    .hero-desc {
      font-size: 1.15rem;
      color: var(--text-muted);
      max-width: 820px;
      margin: 0 auto 36px;
      line-height: 1.7;
    }

    .hero-cta-group {
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 16px;
      margin-bottom: 50px;
      flex-wrap: wrap;
    }

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

    .stat-card {
      background: var(--bg-surface);
      border: 1px solid var(--border-color);
      padding: 24px 16px;
      border-radius: var(--radius);
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
      position: relative;
      overflow: hidden;
    }

    .stat-card::before {
      content: "";
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 3px;
      background: linear-gradient(90deg, var(--primary), var(--accent));
      opacity: 0;
      transition: var(--transition);
    }

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

    .stat-card:hover::before {
      opacity: 1;
    }

    .stat-card .num {
      font-size: 2rem;
      font-weight: 800;
      color: var(--primary);
      line-height: 1.1;
      margin-bottom: 6px;
    }

    .stat-card .label {
      font-size: 0.9rem;
      color: var(--text-muted);
      font-weight: 500;
    }

    /* Section 通用规范 */
    .section {
      padding: 70px 0;
      position: relative;
    }

    .section-header {
      text-align: center;
      margin-bottom: 48px;
    }

    .section-tag {
      font-size: 0.85rem;
      font-weight: 700;
      color: var(--primary);
      text-transform: uppercase;
      letter-spacing: 1.5px;
      margin-bottom: 8px;
      display: inline-block;
    }

    .section-title {
      font-size: 2.1rem;
      font-weight: 700;
      color: var(--text-main);
      line-height: 1.3;
      margin-bottom: 12px;
    }

    .section-subtitle {
      font-size: 1rem;
      color: var(--text-muted);
      max-width: 680px;
      margin: 0 auto;
    }

    /* 卡片网格系统 */
    .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;
    }

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

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

    .card-icon-box {
      width: 52px;
      height: 52px;
      border-radius: 12px;
      background: var(--bg-subtle);
      color: var(--primary);
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 1.5rem;
      margin-bottom: 20px;
      border: 1px solid rgba(121, 40, 202, 0.15);
    }

    .card-title {
      font-size: 1.25rem;
      font-weight: 700;
      color: var(--text-main);
      margin-bottom: 12px;
    }

    .card-text {
      font-size: 0.95rem;
      color: var(--text-muted);
      line-height: 1.6;
      flex-grow: 1;
    }

    /* 场景分类专区 */
    .scene-item {
      background: var(--bg-surface);
      border: 1px solid var(--border-color);
      border-radius: var(--radius);
      padding: 22px;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
    }

    .scene-item:hover {
      border-color: var(--primary);
      transform: translateY(-3px);
      box-shadow: var(--shadow-md);
    }

    .scene-head {
      display: flex;
      align-items: center;
      gap: 12px;
      margin-bottom: 10px;
    }

    .scene-head h3 {
      font-size: 1.1rem;
      font-weight: 700;
      color: var(--text-main);
    }

    .scene-tag {
      font-size: 0.75rem;
      padding: 3px 8px;
      background: var(--bg-subtle);
      color: var(--primary);
      border-radius: 4px;
      font-weight: 600;
    }

    .scene-item p {
      font-size: 0.9rem;
      color: var(--text-muted);
      line-height: 1.55;
    }

    /* 模型徽章列表 */
    .model-pills {
      display: flex;
      flex-wrap: wrap;
      gap: 10px;
      justify-content: center;
      margin-top: 30px;
    }

    .model-pill {
      padding: 8px 16px;
      background: var(--bg-surface);
      border: 1px solid var(--border-color);
      border-radius: 30px;
      font-size: 0.88rem;
      font-weight: 600;
      color: var(--text-main);
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
    }

    .model-pill:hover {
      background: var(--primary);
      color: #ffffff;
      border-color: var(--primary);
      transform: scale(1.05);
    }

    /* 标准流程时间线 */
    .timeline {
      position: relative;
      max-width: 900px;
      margin: 0 auto;
    }

    .timeline-item {
      display: flex;
      gap: 24px;
      margin-bottom: 30px;
      position: relative;
    }

    .timeline-item:last-child {
      margin-bottom: 0;
    }

    .timeline-num {
      width: 44px;
      height: 44px;
      border-radius: 50%;
      background: linear-gradient(135deg, var(--primary), var(--accent));
      color: #fff;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 700;
      font-size: 1.1rem;
      flex-shrink: 0;
      box-shadow: 0 4px 12px rgba(121, 40, 202, 0.25);
    }

    .timeline-content {
      background: var(--bg-surface);
      border: 1px solid var(--border-color);
      border-radius: var(--radius);
      padding: 20px 24px;
      flex-grow: 1;
      box-shadow: var(--shadow-sm);
    }

    .timeline-content h3 {
      font-size: 1.15rem;
      font-weight: 700;
      color: var(--text-main);
      margin-bottom: 6px;
    }

    .timeline-content p {
      font-size: 0.92rem;
      color: var(--text-muted);
    }

    /* 对比评测表格与卡片 */
    .evaluation-card {
      background: linear-gradient(135deg, rgba(121, 40, 202, 0.08) 0%, rgba(255, 0, 128, 0.05) 100%);
      border: 1px solid var(--primary-light);
      border-radius: var(--radius);
      padding: 30px;
      margin-bottom: 36px;
      display: flex;
      align-items: center;
      justify-content: space-between;
      flex-wrap: wrap;
      gap: 20px;
    }

    .eval-score-box {
      display: flex;
      align-items: baseline;
      gap: 8px;
    }

    .eval-score-box .score {
      font-size: 3.5rem;
      font-weight: 900;
      color: var(--primary);
      line-height: 1;
    }

    .eval-score-box .max {
      font-size: 1.2rem;
      color: var(--text-muted);
      font-weight: 600;
    }

    .eval-stars {
      color: #ff9900;
      font-size: 1.4rem;
      letter-spacing: 2px;
      margin-top: 4px;
    }

    .table-container {
      width: 100%;
      overflow-x: auto;
      border-radius: var(--radius);
      border: 1px solid var(--border-color);
      background: var(--bg-surface);
      box-shadow: var(--shadow-sm);
    }

    .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 var(--border-color);
    }

    .compare-table th {
      background: var(--bg-subtle);
      font-weight: 700;
      color: var(--text-main);
    }

    .compare-table tr:last-child td {
      border-bottom: none;
    }

    .compare-table td:nth-child(2) {
      font-weight: 600;
      color: var(--primary);
      background: rgba(121, 40, 202, 0.02);
    }

    /* 案例中心图文卡片 */
    .case-card {
      background: var(--bg-surface);
      border: 1px solid var(--border-color);
      border-radius: var(--radius);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
      display: flex;
      flex-direction: column;
    }

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

    .case-img-wrap {
      width: 100%;
      aspect-ratio: 16/9;
      overflow: hidden;
      background: var(--bg-subtle);
    }

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

    .case-card:hover .case-img-wrap img {
      transform: scale(1.04);
    }

    .case-content {
      padding: 22px;
      flex-grow: 1;
    }

    .case-content h3 {
      font-size: 1.15rem;
      font-weight: 700;
      color: var(--text-main);
      margin-bottom: 8px;
    }

    .case-content p {
      font-size: 0.9rem;
      color: var(--text-muted);
      line-height: 1.55;
    }

    /* 用户评论 */
    .review-card {
      background: var(--bg-surface);
      border: 1px solid var(--border-color);
      border-radius: var(--radius);
      padding: 24px;
      box-shadow: var(--shadow-sm);
      display: flex;
      flex-direction: column;
      justify-content: space-between;
    }

    .review-text {
      font-size: 0.95rem;
      color: var(--text-main);
      line-height: 1.6;
      margin-bottom: 18px;
      font-style: italic;
    }

    .reviewer-meta {
      display: flex;
      align-items: center;
      gap: 12px;
      border-top: 1px solid var(--border-color);
      padding-top: 14px;
    }

    .reviewer-avatar {
      width: 42px;
      height: 42px;
      border-radius: 50%;
      background: linear-gradient(135deg, var(--primary), var(--accent));
      color: #fff;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 700;
      font-size: 1rem;
    }

    .reviewer-info h4 {
      font-size: 0.95rem;
      font-weight: 700;
      color: var(--text-main);
    }

    .reviewer-info p {
      font-size: 0.82rem;
      color: var(--text-muted);
    }

    /* FAQ 手风琴 */
    .faq-container {
      max-width: 900px;
      margin: 0 auto;
      display: flex;
      flex-direction: column;
      gap: 14px;
    }

    .faq-item {
      background: var(--bg-surface);
      border: 1px solid var(--border-color);
      border-radius: var(--radius);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
    }

    .faq-question {
      padding: 20px 24px;
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-weight: 700;
      font-size: 1.05rem;
      color: var(--text-main);
      user-select: none;
    }

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

    .faq-icon {
      font-size: 1.2rem;
      transition: transform 0.25s ease;
      color: var(--primary);
    }

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

    .faq-answer {
      display: none;
      padding: 0 24px 20px;
      font-size: 0.95rem;
      color: var(--text-muted);
      line-height: 1.65;
      border-top: 1px dashed var(--border-color);
      margin-top: -4px;
      padding-top: 16px;
    }

    .faq-item.active .faq-answer {
      display: block;
    }

    /* 需求匹配表单与联系我们 */
    .form-wrapper {
      background: var(--bg-surface);
      border: 1px solid var(--border-color);
      border-radius: var(--radius);
      padding: 36px;
      box-shadow: var(--shadow-md);
    }

    .form-group {
      margin-bottom: 20px;
    }

    .form-group label {
      display: block;
      font-size: 0.9rem;
      font-weight: 600;
      color: var(--text-main);
      margin-bottom: 8px;
    }

    .form-control {
      width: 100%;
      padding: 12px 16px;
      border: 1px solid var(--border-color);
      border-radius: 8px;
      font-size: 0.95rem;
      color: var(--text-main);
      background: var(--bg-main);
      transition: var(--transition);
      font-family: inherit;
    }

    .form-control:focus {
      outline: none;
      border-color: var(--primary);
      background: #ffffff;
      box-shadow: 0 0 0 3px rgba(121, 40, 202, 0.15);
    }

    textarea.form-control {
      resize: vertical;
      min-height: 110px;
    }

    .contact-info-list {
      display: flex;
      flex-direction: column;
      gap: 20px;
    }

    .contact-info-item {
      display: flex;
      align-items: flex-start;
      gap: 16px;
    }

    .contact-icon {
      width: 44px;
      height: 44px;
      border-radius: 10px;
      background: var(--bg-subtle);
      color: var(--primary);
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 1.25rem;
      flex-shrink: 0;
    }

    .contact-detail h4 {
      font-size: 1rem;
      font-weight: 700;
      color: var(--text-main);
      margin-bottom: 4px;
    }

    .contact-detail p, .contact-detail a {
      font-size: 0.92rem;
      color: var(--text-muted);
    }

    .qrcode-box {
      margin-top: 16px;
      display: inline-block;
      padding: 12px;
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: 12px;
      box-shadow: var(--shadow-sm);
    }

    .qrcode-box img {
      width: 130px;
      height: 130px;
      display: block;
      border-radius: 6px;
    }

    .qrcode-tip {
      font-size: 0.8rem;
      text-align: center;
      color: var(--text-muted);
      margin-top: 6px;
    }

    /* 文章列表与资讯 */
    .article-list {
      display: flex;
      flex-direction: column;
      gap: 16px;
    }

    .article-item {
      background: var(--bg-surface);
      border: 1px solid var(--border-color);
      border-radius: var(--radius);
      padding: 18px 24px;
      display: flex;
      justify-content: space-between;
      align-items: center;
      transition: var(--transition);
    }

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

    .article-item h3 {
      font-size: 1rem;
      font-weight: 600;
      color: var(--text-main);
    }

    .article-item .article-link {
      color: var(--primary);
      font-size: 0.9rem;
      font-weight: 600;
      white-space: nowrap;
      margin-left: 16px;
    }

    /* 友情链接与页脚 */
    .footer-section {
      background: #ffffff;
      border-top: 1px solid var(--border-color);
      padding: 50px 0 30px;
      color: var(--text-main);
    }

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

    .footer-col h4 {
      font-size: 1.05rem;
      font-weight: 700;
      color: var(--text-main);
      margin-bottom: 16px;
      position: relative;
    }

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

    .footer-links li a {
      color: var(--text-muted);
      font-size: 0.92rem;
    }

    .footer-links li a:hover {
      color: var(--primary);
    }

    .friend-links-box {
      display: flex;
      flex-wrap: wrap;
      gap: 12px;
      margin-top: 8px;
    }

    .friend-links-box a {
      font-size: 0.88rem;
      color: var(--text-muted);
      background: var(--bg-subtle);
      padding: 6px 12px;
      border-radius: 6px;
      border: 1px solid var(--border-color);
    }

    .friend-links-box a:hover {
      color: var(--primary);
      border-color: var(--primary);
    }

    .footer-bottom {
      border-top: 1px solid var(--border-color);
      padding-top: 24px;
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-size: 0.88rem;
      color: var(--text-muted);
      flex-wrap: wrap;
      gap: 12px;
    }

    /* 悬浮工具栏 */
    .floating-tools {
      position: fixed;
      right: 24px;
      bottom: 40px;
      display: flex;
      flex-direction: column;
      gap: 12px;
      z-index: 999;
    }

    .tool-btn {
      width: 48px;
      height: 48px;
      border-radius: 50%;
      background: #ffffff;
      border: 1px solid var(--border-color);
      color: var(--primary);
      display: flex;
      align-items: center;
      justify-content: center;
      box-shadow: var(--shadow-md);
      cursor: pointer;
      transition: var(--transition);
      font-size: 1.2rem;
    }

    .tool-btn:hover {
      background: var(--primary);
      color: #ffffff;
      transform: scale(1.1);
    }

    /* 响应式调整 */
    @media (max-width: 992px) {
      .hero-title { font-size: 2.2rem; }
      .grid-4 { grid-template-columns: repeat(2, 1fr); }
      .grid-3 { grid-template-columns: repeat(2, 1fr); }
      .footer-grid { grid-template-columns: repeat(2, 1fr); }
      .hero-stats-grid { grid-template-columns: repeat(2, 1fr); }
    }

    @media (max-width: 768px) {
      .header-nav .nav-links {
        display: none;
        position: absolute;
        top: 76px;
        left: 0;
        width: 100%;
        background: #ffffff;
        flex-direction: column;
        padding: 20px;
        border-bottom: 1px solid var(--border-color);
        box-shadow: var(--shadow-md);
      }
      .header-nav .nav-links.show {
        display: flex;
      }
      .mobile-menu-toggle {
        display: block;
      }
      .hero-title { font-size: 1.85rem; }
      .grid-3, .grid-2 { grid-template-columns: 1fr; }
      .grid-4 { grid-template-columns: 1fr; }
      .hero-stats-grid { grid-template-columns: 1fr; }
      .footer-grid { grid-template-columns: 1fr; }
      .evaluation-card { flex-direction: column; text-align: center; }
      .footer-bottom { flex-direction: column; text-align: center; }
    }