:root {
      --primary: #0d9488;
      --primary-light: #14b8a6;
      --primary-dark: #0f766e;
      --primary-soft: #f0fdfa;
      --secondary: #0284c7;
      --accent: #06b6d4;
      --text-main: #0f172a;
      --text-muted: #475569;
      --text-light: #64748b;
      --bg-main: #f8fafc;
      --bg-card: #ffffff;
      --border-color: #e2e8f0;
      --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
      --shadow-md: 0 4px 6px -1px rgba(13, 148, 136, 0.08), 0 2px 4px -2px rgba(0, 0, 0, 0.05);
      --shadow-lg: 0 10px 15px -3px rgba(13, 148, 136, 0.1), 0 4px 6px -4px rgba(0, 0, 0, 0.05);
      --shadow-hover: 0 20px 25px -5px rgba(13, 148, 136, 0.15), 0 8px 10px -6px rgba(0, 0, 0, 0.05);
      --radius: 12px;
      --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    }
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }
    html {
      scroll-behavior: smooth;
      font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
      background-color: var(--bg-main);
      color: var(--text-main);
      line-height: 1.6;
    }
    body {
      background: linear-gradient(180deg, #f0fdfa 0%, #f8fafc 400px, #f8fafc 100%);
      min-height: 100vh;
      display: flex;
      flex-direction: column;
    }
    .container {
      width: 100%;
      max-width: 1240px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 24px;
      padding-right: 24px;
    }
    a {
      color: inherit;
      text-decoration: none;
      transition: var(--transition);
    }
    /* 导航栏 */
    .site-header {
      position: sticky;
      top: 0;
      z-index: 100;
      background: rgba(255, 255, 255, 0.92);
      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: 72px;
    }
    .brand-area {
      display: flex;
      align-items: center;
      gap: 12px;
    }
    .ai-page-logo {
      height: 40px;
      width: auto;
      display: block;
    }
    .brand-title {
      font-size: 20px;
      font-weight: 700;
      color: var(--primary-dark);
      letter-spacing: -0.5px;
    }
    .nav-links {
      display: flex;
      align-items: center;
      gap: 0;
    }
    .nav-link-item {
      font-size: 15px;
      font-weight: 500;
      color: var(--text-muted);
      padding: 8px 14px;
      border-radius: 6px;
    }
    .nav-link-item:hover, .ai-page-home-link:hover {
      color: var(--primary);
      background-color: var(--primary-soft);
    }
    .ai-page-home-link {
      font-size: 15px;
      font-weight: 500;
      color: var(--text-muted);
      padding: 8px 14px;
      border-radius: 6px;
    }
    .nav-actions {
      display: flex;
      align-items: center;
      gap: 12px;
    }
    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      font-size: 15px;
      font-weight: 600;
      padding: 10px 22px;
      border-radius: 8px;
      cursor: pointer;
      border: 1px solid transparent;
      transition: var(--transition);
      white-space: nowrap;
    }
    .btn-primary {
      background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
      color: #ffffff;
      box-shadow: 0 4px 12px rgba(13, 148, 136, 0.25);
    }
    .btn-primary:hover {
      background: linear-gradient(135deg, var(--primary-light) 0%, var(--primary) 100%);
      transform: translateY(-2px);
      box-shadow: 0 6px 16px rgba(13, 148, 136, 0.35);
      color: #ffffff;
    }
    .btn-outline {
      border-color: var(--primary);
      color: var(--primary);
      background: transparent;
    }
    .btn-outline:hover {
      background: var(--primary-soft);
      transform: translateY(-2px);
    }
    .btn-secondary {
      background: #ffffff;
      color: var(--text-main);
      border-color: var(--border-color);
    }
    .btn-secondary:hover {
      border-color: var(--primary);
      color: var(--primary);
    }
    .mobile-menu-btn {
      display: none;
      background: none;
      border: none;
      cursor: pointer;
      padding: 8px;
      color: var(--text-main);
    }
    /* Hero首屏 - 严格无图纯CSS设计 */
    .hero-section {
      padding: 80px 0 60px;
      position: relative;
      overflow: hidden;
      background: radial-gradient(circle at 50% 0%, rgba(20, 184, 166, 0.12) 0%, rgba(248, 250, 252, 0) 70%);
    }
    .hero-grid {
      display: grid;
      grid-template-columns: 1.2fr 0.8fr;
      gap: 48px;
      align-items: center;
    }
    .hero-badge {
      display: inline-flex;
      align-items: center;
      gap: 8px;
      padding: 6px 16px;
      background: var(--primary-soft);
      border: 1px solid rgba(13, 148, 136, 0.2);
      border-radius: 9999px;
      color: var(--primary-dark);
      font-size: 13px;
      font-weight: 600;
      margin-bottom: 20px;
    }
    .hero-title {
      font-size: 40px;
      line-height: 1.25;
      font-weight: 800;
      color: var(--text-main);
      margin-bottom: 20px;
      letter-spacing: -0.5px;
    }
    .hero-desc {
      font-size: 18px;
      color: var(--text-muted);
      line-height: 1.7;
      margin-bottom: 36px;
    }
    .hero-cta-group {
      display: flex;
      flex-wrap: wrap;
      gap: 16px;
      align-items: center;
      margin-bottom: 40px;
    }
    .hero-highlight-card {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: 16px;
      padding: 32px;
      box-shadow: var(--shadow-lg);
      position: relative;
    }
    .terminal-header {
      display: flex;
      gap: 8px;
      margin-bottom: 20px;
    }
    .dot {
      width: 12px;
      height: 12px;
      border-radius: 50%;
    }
    .dot-red { background: #ef4444; }
    .dot-yellow { background: #f59e0b; }
    .dot-green { background: #10b981; }
    .hero-stats-grid {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 16px;
    }
    .stat-box {
      background: var(--bg-main);
      padding: 16px;
      border-radius: 10px;
      border: 1px solid rgba(226, 232, 240, 0.8);
      border-left: 4px solid var(--primary);
    }
    .stat-num {
      font-size: 26px;
      font-weight: 700;
      color: var(--primary-dark);
      line-height: 1.2;
    }
    .stat-label {
      font-size: 13px;
      color: var(--text-light);
      margin-top: 4px;
    }
    /* 核心矩阵标签云 */
    .models-stream {
      display: flex;
      flex-wrap: wrap;
      gap: 8px;
      margin-top: 20px;
    }
    .model-chip {
      background: #ffffff;
      border: 1px solid var(--border-color);
      padding: 4px 12px;
      border-radius: 6px;
      font-size: 12px;
      font-weight: 500;
      color: var(--text-muted);
      transition: var(--transition);
    }
    .model-chip:hover {
      border-color: var(--primary);
      color: var(--primary);
      transform: translateY(-1px);
    }
    /* 通用章节 */
    .section-wrap {
      padding: 64px 0;
    }
    .section-head {
      text-align: center;
      max-width: 720px;
      margin: 0 auto 48px;
    }
    .section-tag {
      display: inline-block;
      color: var(--primary);
      font-size: 13px;
      font-weight: 700;
      text-transform: uppercase;
      letter-spacing: 1px;
      margin-bottom: 8px;
    }
    .section-title {
      font-size: 30px;
      font-weight: 700;
      color: var(--text-main);
      margin-bottom: 12px;
    }
    .section-sub {
      font-size: 16px;
      color: var(--text-muted);
      line-height: 1.6;
    }
    /* 卡片网格 */
    .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;
    }
    .card {
      background: var(--bg-card);
      border: 1px solid var(--border-color);
      border-radius: var(--radius);
      padding: 24px;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
      display: flex;
      flex-direction: column;
    }
    .card:hover {
      border-color: var(--primary-light);
      box-shadow: var(--shadow-hover);
      transform: translateY(-4px);
    }
    .card-icon {
      width: 48px;
      height: 48px;
      border-radius: 10px;
      background: var(--primary-soft);
      color: var(--primary);
      display: flex;
      align-items: center;
      justify-content: center;
      margin-bottom: 18px;
    }
    .card-icon svg {
      width: 24px;
      height: 24px;
      stroke-width: 2;
    }
    .card-title {
      font-size: 18px;
      font-weight: 600;
      color: var(--text-main);
      margin-bottom: 10px;
    }
    .card-desc {
      font-size: 14px;
      color: var(--text-muted);
      line-height: 1.6;
      flex-grow: 1;
    }
    /* 流程步骤 */
    .process-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 20px;
      position: relative;
    }
    .step-card {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius);
      padding: 24px;
      position: relative;
    }
    .step-badge {
      display: inline-block;
      width: 32px;
      height: 32px;
      background: var(--primary);
      color: #ffffff;
      border-radius: 50%;
      text-align: center;
      line-height: 32px;
      font-weight: 700;
      margin-bottom: 16px;
      font-size: 14px;
    }
    /* 对比表格 */
    .compare-container {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius);
      box-shadow: var(--shadow-md);
      overflow-x: auto;
    }
    .compare-table {
      width: 100%;
      border-collapse: collapse;
      text-align: left;
      min-width: 650px;
    }
    .compare-table th, .compare-table td {
      padding: 16px 20px;
      border-bottom: 1px solid var(--border-color);
      font-size: 14px;
    }
    .compare-table th {
      background: #f1f5f9;
      color: var(--text-main);
      font-weight: 600;
    }
    .compare-table tr:last-child td {
      border-bottom: none;
    }
    .highlight-col {
      background: var(--primary-soft);
      font-weight: 600;
      color: var(--primary-dark);
    }
    .score-badge {
      display: inline-flex;
      align-items: center;
      gap: 4px;
      background: #fef08a;
      color: #854d0e;
      padding: 4px 10px;
      border-radius: 20px;
      font-weight: 700;
      font-size: 13px;
    }
    /* 图片展示区 */
    .media-card {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
    }
    .media-card:hover {
      box-shadow: var(--shadow-lg);
      transform: translateY(-3px);
    }
    .media-thumb-box {
      width: 100%;
      aspect-ratio: 16 / 9;
      background: #e2e8f0;
      overflow: hidden;
    }
    .media-thumb-square {
      width: 100%;
      aspect-ratio: 1 / 1;
      background: #e2e8f0;
      overflow: hidden;
    }
    .media-img {
      width: 100%;
      height: 100%;
      object-fit: cover;
      display: block;
      transition: transform 0.5s ease;
    }
    .media-card:hover .media-img {
      transform: scale(1.04);
    }
    .media-body {
      padding: 20px;
    }
    /* FAQ 展开手风琴 */
    .faq-list {
      max-width: 900px;
      margin: 0 auto;
      display: flex;
      flex-direction: column;
      gap: 12px;
    }
    .faq-item {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius);
      overflow: hidden;
      transition: var(--transition);
    }
    .faq-trigger {
      width: 100%;
      padding: 20px 24px;
      display: flex;
      justify-content: space-between;
      align-items: center;
      background: none;
      border: none;
      text-align: left;
      font-size: 16px;
      font-weight: 600;
      color: var(--text-main);
      cursor: pointer;
    }
    .faq-icon {
      transition: transform 0.3s ease;
      color: var(--primary);
    }
    .faq-content {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      background: #fafafa;
    }
    .faq-body {
      padding: 0 24px 20px;
      font-size: 14px;
      color: var(--text-muted);
      line-height: 1.7;
    }
    .faq-item.active .faq-icon {
      transform: rotate(180deg);
    }
    /* 表单板块 */
    .form-container {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: 16px;
      padding: 40px;
      box-shadow: var(--shadow-lg);
    }
    .form-row {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 20px;
      margin-bottom: 20px;
    }
    .form-group {
      display: flex;
      flex-direction: column;
      gap: 8px;
      margin-bottom: 20px;
    }
    .form-label {
      font-size: 14px;
      font-weight: 600;
      color: var(--text-main);
    }
    .form-input, .form-select, .form-textarea {
      width: 100%;
      padding: 12px 16px;
      border: 1px solid var(--border-color);
      border-radius: 8px;
      font-size: 14px;
      color: var(--text-main);
      background: #f8fafc;
      transition: var(--transition);
    }
    .form-input:focus, .form-select:focus, .form-textarea:focus {
      outline: none;
      border-color: var(--primary);
      background: #ffffff;
      box-shadow: 0 0 0 3px rgba(13, 148, 136, 0.15);
    }
    /* 用户评论 */
    .testimonial-author {
      display: flex;
      align-items: center;
      gap: 12px;
      margin-top: 20px;
      padding-top: 16px;
      border-top: 1px solid var(--border-color);
    }
    .avatar-fake {
      width: 44px;
      height: 44px;
      border-radius: 50%;
      background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
      color: #ffffff;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 700;
      font-size: 16px;
    }
    .author-info h4 {
      font-size: 15px;
      color: var(--text-main);
    }
    .author-info p {
      font-size: 12px;
      color: var(--text-light);
    }
    /* 推广大Banner */
    .banner-box {
      margin: 40px 0;
      border-radius: 16px;
      overflow: hidden;
      border: 1px solid var(--border-color);
      box-shadow: var(--shadow-md);
    }
    .banner-box img {
      width: 100%;
      height: auto;
      display: block;
    }
    /* 页脚样式 */
    .site-footer {
      background: #0f172a;
      color: #94a3b8;
      padding-top: 60px;
      margin-top: 60px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 1.5fr 1fr 1fr 1fr;
      gap: 40px;
      padding-bottom: 40px;
      border-bottom: 1px solid #334155;
    }
    .footer-col h3 {
      color: #f8fafc;
      font-size: 16px;
      font-weight: 600;
      margin-bottom: 20px;
    }
    .footer-links {
      list-style: none;
      display: flex;
      flex-direction: column;
      gap: 10px;
    }
    .footer-links a, .footer-col a {
      color: #94a3b8;
      font-size: 14px;
    }
    .footer-links a:hover, .footer-col a:hover {
      color: var(--primary-light);
    }
    .footer-bottom {
      padding: 24px 0;
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-size: 13px;
    }
    .friend-links-area {
      padding: 24px 0;
      border-bottom: 1px solid #334155;
      display: flex;
      flex-wrap: wrap;
      gap: 16px;
      align-items: center;
      font-size: 13px;
    }
    .friend-links-area a {
      color: #94a3b8;
    }
    .friend-links-area a:hover {
      color: #ffffff;
    }
    /* 浮动组件 */
    .floating-kefu {
      position: fixed;
      right: 24px;
      bottom: 32px;
      z-index: 99;
      display: flex;
      flex-direction: column;
      gap: 10px;
    }
    .kefu-btn {
      width: 50px;
      height: 50px;
      border-radius: 50%;
      background: var(--primary);
      color: #ffffff;
      display: flex;
      align-items: center;
      justify-content: center;
      box-shadow: 0 4px 14px rgba(13, 148, 136, 0.4);
      cursor: pointer;
      position: relative;
    }
    .kefu-popup {
      position: absolute;
      right: 60px;
      bottom: 0;
      width: 180px;
      background: #ffffff;
      padding: 16px;
      border-radius: 12px;
      box-shadow: var(--shadow-lg);
      border: 1px solid var(--border-color);
      display: none;
      text-align: center;
    }
    .kefu-popup img {
      width: 100%;
      height: auto;
      border-radius: 6px;
      margin-bottom: 8px;
    }
    .kefu-popup span {
      font-size: 12px;
      color: var(--text-main);
      font-weight: 600;
    }
    .kefu-btn:hover .kefu-popup {
      display: block;
    }
    /* 响应式适配 */
    @media (max-width: 1024px) {
      .hero-grid { grid-template-columns: 1fr; }
      .grid-3 { grid-template-columns: repeat(2, 1fr); }
      .grid-4 { grid-template-columns: repeat(2, 1fr); }
      .process-grid { grid-template-columns: repeat(2, 1fr); }
      .footer-grid { grid-template-columns: repeat(2, 1fr); }
    }
    @media (max-width: 768px) {
      .nav-links { display: none; }
      .mobile-menu-btn { display: block; }
      .hero-title { font-size: 28px; }
      .hero-desc { font-size: 15px; }
      .grid-3, .grid-4, .grid-2, .process-grid { grid-template-columns: 1fr; }
      .form-row { grid-template-columns: 1fr; }
      .footer-grid { grid-template-columns: 1fr; }
      .footer-bottom { flex-direction: column; gap: 12px; text-align: center; }
      .section-wrap { padding: 40px 0; }
      .hero-stats-grid { grid-template-columns: 1fr; }
    }