:root {
      --primary: #2563eb;
      --primary-dark: #1d4ed8;
      --accent: #f97316;
      --accent-light: #ffedd5;
      --cyan: #06b6d4;
      --bg-light: #f8fafc;
      --bg-white: #ffffff;
      --bg-subtle: #f1f5f9;
      --text-main: #0f172a;
      --text-muted: #475569;
      --text-light: #64748b;
      --border-color: #e2e8f0;
      --border-bright: #cbd5e1;
      --shadow-sm: 0 1px 3px rgba(0,0,0,0.05);
      --shadow-md: 0 4px 12px rgba(15, 23, 42, 0.08);
      --shadow-lg: 0 12px 28px rgba(15, 23, 42, 0.12);
      --radius: 12px;
    }

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

    html {
      scroll-behavior: smooth;
      font-size: 16px;
    }

    body {
      font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
      background-color: var(--bg-light);
      color: var(--text-main);
      line-height: 1.6;
      overflow-x: hidden;
    }

    a {
      color: inherit;
      text-decoration: none;
      transition: color 0.2s ease;
    }

    .site-container {
      width: 100%;
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 20px;
    }

    /* 顶部导航栏 */
    .site-header {
      position: sticky;
      top: 0;
      z-index: 1000;
      background: rgba(255, 255, 255, 0.95);
      backdrop-filter: blur(8px);
      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-group {
      display: flex;
      align-items: center;
      gap: 12px;
    }

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

    .brand-title {
      font-size: 1.35rem;
      font-weight: 800;
      color: var(--primary-dark);
      letter-spacing: -0.5px;
    }

    .nav-links {
      display: flex;
      align-items: center;
      gap: 0;
    }

    .nav-links a {
      padding: 8px 12px;
      font-size: 0.95rem;
      font-weight: 500;
      color: var(--text-muted);
      border-radius: 6px;
      transition: all 0.2s ease;
    }

    .nav-links a:hover,
    .nav-links a.active {
      color: var(--primary);
      background-color: #eff6ff;
    }

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

    .btn-primary {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 10px 22px;
      background: linear-gradient(135deg, var(--primary) 0%, #1e40af 100%);
      color: #ffffff !important;
      font-weight: 600;
      border-radius: 8px;
      border: none;
      cursor: pointer;
      box-shadow: 0 2px 8px rgba(37, 99, 235, 0.3);
      transition: transform 0.15s ease, box-shadow 0.15s ease;
    }

    .btn-primary:hover {
      transform: translateY(-2px);
      box-shadow: 0 4px 14px rgba(37, 99, 235, 0.4);
    }

    .btn-outline {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 9px 20px;
      border: 1px solid var(--primary);
      color: var(--primary);
      background-color: transparent;
      font-weight: 600;
      border-radius: 8px;
      cursor: pointer;
      transition: all 0.2s ease;
    }

    .btn-outline:hover {
      background-color: #eff6ff;
      border-color: var(--primary-dark);
    }

    .menu-toggle {
      display: none;
      background: none;
      border: none;
      padding: 8px;
      cursor: pointer;
    }

    .menu-toggle span {
      display: block;
      width: 22px;
      height: 2px;
      background-color: var(--text-main);
      margin: 4px 0;
      transition: 0.3s;
    }

    /* 模块通用样式 */
    .section {
      padding: 72px 0;
      border-bottom: 1px solid var(--border-color);
    }

    .section-alt {
      background-color: var(--bg-white);
    }

    .section-header {
      text-align: center;
      max-width: 760px;
      margin: 0 auto 50px auto;
    }

    .section-tag {
      display: inline-block;
      padding: 4px 12px;
      background-color: #eff6ff;
      color: var(--primary);
      font-size: 0.85rem;
      font-weight: 700;
      border-radius: 20px;
      text-transform: uppercase;
      margin-bottom: 12px;
      border: 1px solid #bfdbfe;
    }

    .section-title {
      font-size: 2.1rem;
      font-weight: 800;
      color: var(--text-main);
      margin-bottom: 14px;
      line-height: 1.3;
    }

    .section-desc {
      font-size: 1.05rem;
      color: var(--text-muted);
    }

    /* 首屏 Hero */
    .hero-section {
      padding: 80px 0 90px;
      background: radial-gradient(circle at 50% 0%, #dbeafe 0%, #f8fafc 70%);
      text-align: center;
      position: relative;
    }

    .hero-badge-wrap {
      display: inline-flex;
      align-items: center;
      gap: 8px;
      background: #ffffff;
      border: 1px solid #bfdbfe;
      padding: 6px 16px;
      border-radius: 30px;
      box-shadow: var(--shadow-sm);
      margin-bottom: 24px;
    }

    .hero-badge-tag {
      background-color: var(--accent);
      color: #fff;
      font-size: 0.75rem;
      font-weight: bold;
      padding: 2px 8px;
      border-radius: 12px;
    }

    .hero-badge-text {
      font-size: 0.88rem;
      color: var(--text-muted);
      font-weight: 500;
    }

    .hero-title {
      font-size: 2.8rem;
      font-weight: 900;
      line-height: 1.25;
      margin-bottom: 20px;
      color: #0f172a;
      letter-spacing: -0.5px;
    }

    .hero-title-highlight {
      background: linear-gradient(135deg, #1d4ed8 0%, #0284c7 100%);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
    }

    .hero-lead {
      font-size: 1.2rem;
      color: var(--text-muted);
      max-width: 820px;
      margin: 0 auto 36px auto;
      line-height: 1.7;
    }

    .hero-cta-group {
      display: flex;
      justify-content: center;
      align-items: center;
      gap: 16px;
      margin-bottom: 48px;
      flex-wrap: wrap;
    }

    .hero-cta-group .btn-primary {
      padding: 14px 34px;
      font-size: 1.05rem;
    }

    .hero-cta-group .btn-outline {
      padding: 13px 30px;
      font-size: 1.05rem;
    }

    .metrics-bar {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 20px;
      max-width: 1040px;
      margin: 0 auto;
      background: #ffffff;
      padding: 28px 24px;
      border-radius: 16px;
      border: 1px solid var(--border-color);
      box-shadow: var(--shadow-md);
    }

    .metric-item {
      text-align: center;
      border-right: 1px solid #f1f5f9;
    }

    .metric-item:last-child {
      border-right: none;
    }

    .metric-num {
      font-size: 2rem;
      font-weight: 800;
      color: var(--primary-dark);
      line-height: 1;
      margin-bottom: 8px;
    }

    .metric-label {
      font-size: 0.9rem;
      color: var(--text-light);
      font-weight: 500;
    }

    /* 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;
    }

    .service-card {
      background: var(--bg-white);
      border: 1px solid var(--border-color);
      border-radius: var(--radius);
      padding: 26px;
      transition: all 0.25s ease;
      display: flex;
      flex-direction: column;
      height: 100%;
    }

    .service-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-lg);
      border-color: #93c5fd;
    }

    .card-icon-box {
      width: 48px;
      height: 48px;
      background-color: #eff6ff;
      border-radius: 10px;
      display: flex;
      align-items: center;
      justify-content: center;
      color: var(--primary);
      font-weight: 800;
      font-size: 1.25rem;
      margin-bottom: 16px;
    }

    .card-title {
      font-size: 1.15rem;
      font-weight: 700;
      margin-bottom: 10px;
      color: var(--text-main);
    }

    .card-text {
      font-size: 0.93rem;
      color: var(--text-muted);
      line-height: 1.6;
      flex-grow: 1;
    }

    .card-tag-pill {
      display: inline-block;
      font-size: 0.75rem;
      font-weight: 600;
      color: var(--primary);
      background-color: #f0fdf4;
      border: 1px solid #bbf7d0;
      color: #166534;
      padding: 2px 8px;
      border-radius: 4px;
      margin-top: 14px;
      align-self: flex-start;
    }

    /* 模型矩阵胶囊群 */
    .model-tags-container {
      display: flex;
      flex-wrap: wrap;
      gap: 10px;
      justify-content: center;
      margin-top: 30px;
      padding: 24px;
      background: var(--bg-white);
      border-radius: var(--radius);
      border: 1px solid var(--border-color);
    }

    .model-pill {
      padding: 8px 16px;
      background: var(--bg-subtle);
      border: 1px solid var(--border-color);
      border-radius: 20px;
      font-size: 0.9rem;
      font-weight: 600;
      color: var(--text-muted);
      transition: all 0.2s ease;
    }

    .model-pill:hover {
      background: #eff6ff;
      color: var(--primary);
      border-color: #93c5fd;
    }

    /* 流程步骤 */
    .step-list {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 20px;
      position: relative;
    }

    .step-item {
      background: var(--bg-white);
      border: 1px solid var(--border-color);
      border-radius: var(--radius);
      padding: 24px;
      position: relative;
    }

    .step-index {
      font-size: 1.8rem;
      font-weight: 900;
      color: #93c5fd;
      line-height: 1;
      margin-bottom: 12px;
    }

    .step-heading {
      font-size: 1.1rem;
      font-weight: 700;
      margin-bottom: 8px;
    }

    .step-desc {
      font-size: 0.9rem;
      color: var(--text-muted);
    }

    /* 对比评测模块 */
    .eval-highlight-box {
      background: linear-gradient(135deg, #1e3a8a 0%, #1e40af 100%);
      border-radius: var(--radius);
      padding: 36px;
      color: #ffffff;
      margin-bottom: 30px;
      display: flex;
      justify-content: space-between;
      align-items: center;
      flex-wrap: wrap;
      gap: 24px;
    }

    .eval-highlight-left h3 {
      font-size: 1.6rem;
      margin-bottom: 8px;
    }

    .eval-highlight-left p {
      color: #bfdbfe;
      font-size: 0.98rem;
    }

    .eval-score-badge {
      display: flex;
      align-items: baseline;
      gap: 10px;
      background: rgba(255, 255, 255, 0.15);
      padding: 16px 28px;
      border-radius: 12px;
      backdrop-filter: blur(4px);
    }

    .eval-stars {
      color: #facc15;
      font-size: 1.4rem;
      letter-spacing: 2px;
    }

    .eval-score-val {
      font-size: 2.8rem;
      font-weight: 900;
      line-height: 1;
      color: #ffffff;
    }

    .eval-score-max {
      font-size: 1.1rem;
      color: #cbd5e1;
    }

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

    .eval-table {
      width: 100%;
      border-collapse: collapse;
      text-align: left;
      min-width: 680px;
    }

    .eval-table th,
    .eval-table td {
      padding: 18px 22px;
      border-bottom: 1px solid var(--border-color);
      font-size: 0.95rem;
    }

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

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

    .eval-table .highlight-col {
      background-color: #f0fdf4;
      font-weight: 600;
      color: #166534;
    }

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

    .case-media {
      width: 100%;
      background: #e2e8f0;
      aspect-ratio: 16/9;
      display: flex;
      align-items: center;
      justify-content: center;
      overflow: hidden;
    }

    .case-media.square {
      aspect-ratio: 1/1;
    }

    .case-media img {
      width: 100%;
      height: 100%;
      object-fit: cover;
      display: block;
      transition: transform 0.3s ease;
    }

    .case-media:hover img {
      transform: scale(1.03);
    }

    .case-body {
      padding: 22px;
      flex-grow: 1;
      display: flex;
      flex-direction: column;
    }

    .case-tag {
      font-size: 0.78rem;
      font-weight: 700;
      color: var(--primary);
      text-transform: uppercase;
      margin-bottom: 6px;
    }

    .case-title {
      font-size: 1.1rem;
      font-weight: 700;
      margin-bottom: 8px;
    }

    .case-desc {
      font-size: 0.9rem;
      color: var(--text-muted);
      margin-bottom: 16px;
      flex-grow: 1;
    }

    /* 用户评论 */
    .review-card {
      background: var(--bg-white);
      border: 1px solid var(--border-color);
      border-radius: var(--radius);
      padding: 24px;
      display: flex;
      flex-direction: column;
      justify-content: space-between;
      height: 100%;
    }

    .review-stars {
      color: #eab308;
      font-size: 1rem;
      margin-bottom: 12px;
    }

    .review-content {
      font-size: 0.93rem;
      color: var(--text-muted);
      line-height: 1.6;
      margin-bottom: 20px;
    }

    .review-user {
      display: flex;
      align-items: center;
      gap: 12px;
      border-top: 1px solid #f1f5f9;
      padding-top: 14px;
    }

    .review-avatar {
      width: 42px;
      height: 42px;
      border-radius: 50%;
      background: #e0f2fe;
      color: var(--primary);
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 800;
      font-size: 1rem;
    }

    .review-meta h4 {
      font-size: 0.92rem;
      font-weight: 700;
      color: var(--text-main);
    }

    .review-meta p {
      font-size: 0.78rem;
      color: var(--text-light);
    }

    /* FAQ 手风琴 */
    .faq-accordion {
      max-width: 860px;
      margin: 0 auto;
      display: flex;
      flex-direction: column;
      gap: 12px;
    }

    .faq-item {
      background: var(--bg-white);
      border: 1px solid var(--border-color);
      border-radius: 10px;
      overflow: hidden;
      transition: all 0.2s ease;
    }

    .faq-question {
      width: 100%;
      text-align: left;
      padding: 18px 22px;
      background: none;
      border: none;
      font-size: 1.02rem;
      font-weight: 600;
      color: var(--text-main);
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
    }

    .faq-question:hover {
      background-color: #f8fafc;
    }

    .faq-icon {
      font-size: 1.25rem;
      font-weight: 400;
      color: var(--primary);
      transition: transform 0.25s ease;
    }

    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s cubic-bezier(0.4, 0, 0.2, 1);
      background-color: #fafbfc;
    }

    .faq-answer-inner {
      padding: 0 22px 18px 22px;
      font-size: 0.93rem;
      color: var(--text-muted);
      line-height: 1.6;
    }

    .faq-item.active .faq-icon {
      transform: rotate(45deg);
    }

    /* 需求匹配与联系表单 */
    .form-wrapper {
      max-width: 760px;
      margin: 0 auto;
      background: var(--bg-white);
      border: 1px solid var(--border-color);
      border-radius: 16px;
      padding: 36px;
      box-shadow: var(--shadow-sm);
    }

    .form-row {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 20px;
      margin-bottom: 20px;
    }

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

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

    .form-control {
      width: 100%;
      padding: 12px 14px;
      font-size: 0.95rem;
      border: 1px solid var(--border-bright);
      border-radius: 8px;
      outline: none;
      background-color: #f8fafc;
      transition: border-color 0.2s ease, box-shadow 0.2s ease;
    }

    .form-control:focus {
      border-color: var(--primary);
      background-color: #ffffff;
      box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.15);
    }

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

    .btn-submit {
      width: 100%;
      padding: 14px;
      font-size: 1.05rem;
      font-weight: 700;
      color: #ffffff;
      background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
      border: none;
      border-radius: 8px;
      cursor: pointer;
      box-shadow: 0 4px 12px rgba(37, 99, 235, 0.25);
      transition: all 0.2s ease;
    }

    .btn-submit:hover {
      box-shadow: 0 6px 16px rgba(37, 99, 235, 0.35);
      transform: translateY(-1px);
    }

    /* 资讯与百科 */
    .article-card {
      background: var(--bg-white);
      border: 1px solid var(--border-color);
      border-radius: var(--radius);
      padding: 22px;
      display: flex;
      flex-direction: column;
      justify-content: space-between;
      height: 100%;
    }

    .article-title {
      font-size: 1.05rem;
      font-weight: 700;
      margin-bottom: 10px;
      color: var(--text-main);
    }

    .article-excerpt {
      font-size: 0.9rem;
      color: var(--text-muted);
      margin-bottom: 16px;
    }

    .article-link {
      font-size: 0.88rem;
      font-weight: 600;
      color: var(--primary);
      display: inline-flex;
      align-items: center;
      gap: 4px;
    }

    /* 底部专属模块 */
    .site-footer {
      background-color: #0f172a;
      color: #cbd5e1;
      padding: 60px 0 30px;
      border-top: 1px solid #1e293b;
    }

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

    .footer-brand h3 {
      color: #ffffff;
      font-size: 1.4rem;
      margin-bottom: 14px;
    }

    .footer-brand p {
      font-size: 0.9rem;
      color: #94a3b8;
      line-height: 1.6;
      margin-bottom: 16px;
    }

    .footer-col h4 {
      color: #ffffff;
      font-size: 1.05rem;
      font-weight: 700;
      margin-bottom: 18px;
    }

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

    .footer-links a {
      color: #94a3b8;
      font-size: 0.9rem;
    }

    .footer-links a:hover {
      color: #ffffff;
    }

    .footer-contact-item {
      font-size: 0.9rem;
      color: #94a3b8;
      margin-bottom: 10px;
    }

    .footer-qr-wrap {
      display: flex;
      align-items: center;
      gap: 12px;
      margin-top: 12px;
    }

    .footer-qr-img {
      width: 76px;
      height: 76px;
      border-radius: 6px;
      background: #ffffff;
      padding: 4px;
    }

    .footer-qr-desc {
      font-size: 0.8rem;
      color: #94a3b8;
    }

    .footer-bottom {
      border-top: 1px solid #1e293b;
      padding-top: 24px;
      display: flex;
      justify-content: space-between;
      align-items: center;
      flex-wrap: wrap;
      gap: 16px;
      font-size: 0.85rem;
      color: #64748b;
    }

    .footer-friendly-links {
      display: flex;
      flex-wrap: wrap;
      gap: 14px;
      align-items: center;
    }

    .footer-friendly-links a {
      color: #94a3b8;
    }

    .footer-friendly-links a:hover {
      color: #ffffff;
    }

    /* 浮动客服入口 */
    .float-contact {
      position: fixed;
      right: 20px;
      bottom: 40px;
      z-index: 999;
      display: flex;
      flex-direction: column;
      gap: 10px;
    }

    .float-btn {
      width: 48px;
      height: 48px;
      border-radius: 50%;
      background: var(--primary);
      color: #ffffff;
      display: flex;
      align-items: center;
      justify-content: center;
      box-shadow: 0 4px 12px rgba(0,0,0,0.18);
      cursor: pointer;
      position: relative;
      transition: transform 0.2s ease;
    }

    .float-btn:hover {
      transform: scale(1.08);
    }

    .float-qr-card {
      position: absolute;
      right: 60px;
      bottom: 0;
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: 12px;
      padding: 14px;
      box-shadow: var(--shadow-lg);
      display: none;
      width: 170px;
      text-align: center;
    }

    .float-qr-card img {
      width: 140px;
      height: 140px;
      display: block;
      margin: 0 auto 6px auto;
    }

    .float-qr-card span {
      font-size: 0.78rem;
      color: var(--text-muted);
      display: block;
    }

    .float-btn:hover .float-qr-card {
      display: block;
    }

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

    @media (max-width: 768px) {
      .menu-toggle {
        display: block;
      }
      .nav-links {
        position: absolute;
        top: 72px;
        left: 0;
        right: 0;
        background: #ffffff;
        flex-direction: column;
        align-items: flex-start;
        padding: 16px 20px;
        border-bottom: 1px solid var(--border-color);
        box-shadow: var(--shadow-md);
        display: none;
      }
      .nav-links.show {
        display: flex;
      }
      .nav-links a {
        width: 100%;
        padding: 10px 0;
      }
      .grid-3, .grid-4, .grid-2 {
        grid-template-columns: 1fr;
      }
      .step-list {
        grid-template-columns: 1fr;
      }
      .metrics-bar {
        grid-template-columns: repeat(2, 1fr);
        gap: 16px;
      }
      .metric-item {
        border-right: none;
      }
      .form-row {
        grid-template-columns: 1fr;
      }
      .footer-grid {
        grid-template-columns: 1fr;
      }
      .eval-highlight-box {
        flex-direction: column;
        align-items: flex-start;
      }
    }