:root {
      --bg-main: #f8fafc;
      --bg-card: #ffffff;
      --bg-alt: #f1f5f9;
      --text-main: #0f172a;
      --text-muted: #475569;
      --text-light: #64748b;
      --color-primary: #4f46e5;
      --color-primary-hover: #4338ca;
      --color-accent-pink: #ec4899;
      --color-accent-cyan: #06b6d4;
      --color-accent-orange: #f97316;
      --color-accent-emerald: #10b981;
      --border-color: #e2e8f0;
      --shadow-sm: 0 2px 4px rgba(15, 23, 42, 0.05);
      --shadow-md: 0 10px 25px -5px rgba(15, 23, 42, 0.08);
      --shadow-hover: 0 20px 30px -10px rgba(79, 70, 229, 0.15);
      --radius-sm: 8px;
      --radius-md: 14px;
      --radius-lg: 20px;
      --container-max: 1200px;
    }

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

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

    body {
      background-color: var(--bg-main);
      color: var(--text-main);
      font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
      line-height: 1.6;
      overflow-x: hidden;
      display: flex;
      flex-direction: column;
      min-height: 100vh;
    }

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

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

    /* 顶部导航 */
    .site-header {
      position: sticky;
      top: 0;
      z-index: 1000;
      background: rgba(255, 255, 255, 0.95);
      backdrop-filter: blur(12px);
      border-bottom: 2px solid var(--border-color);
    }

    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 72px;
    }

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

    .ai-page-logo {
      height: 42px;
      width: auto;
      display: block;
    }

    .brand-title {
      font-size: 1.25rem;
      font-weight: 800;
      color: var(--color-primary);
      letter-spacing: -0.5px;
    }

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

    .nav-links li a {
      font-size: 0.92rem;
      font-weight: 600;
      color: var(--text-main);
      padding: 8px 12px;
      border-radius: var(--radius-sm);
      display: inline-block;
    }

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

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

    .btn-contrast-glow {
      background: linear-gradient(135deg, var(--color-accent-pink), var(--color-primary));
      color: #ffffff !important;
      font-weight: 700;
      padding: 10px 20px;
      border-radius: 50px;
      font-size: 0.92rem;
      box-shadow: 0 4px 14px rgba(236, 72, 153, 0.35);
      display: inline-flex;
      align-items: center;
      justify-content: center;
    }

    .btn-contrast-glow:hover {
      transform: translateY(-2px);
      box-shadow: 0 6px 20px rgba(79, 70, 229, 0.45);
    }

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

    /* 视觉首屏 - 严禁出现图片 */
    .hero-section {
      background: radial-gradient(circle at 10% 20%, rgba(236, 72, 153, 0.08) 0%, transparent 40%),
                  radial-gradient(circle at 90% 80%, rgba(6, 182, 212, 0.08) 0%, transparent 40%),
                  #ffffff;
      border-bottom: 1px solid var(--border-color);
      padding: 70px 0 60px;
      position: relative;
    }

    .hero-content {
      text-align: center;
      max-width: 960px;
      margin: 0 auto;
    }

    .badge-contrast {
      display: inline-flex;
      align-items: center;
      gap: 8px;
      background: rgba(79, 70, 229, 0.1);
      color: var(--color-primary);
      border: 1px solid rgba(79, 70, 229, 0.2);
      padding: 6px 16px;
      border-radius: 30px;
      font-size: 0.88rem;
      font-weight: 700;
      margin-bottom: 20px;
    }

    .hero-title {
      font-size: 2.5rem;
      line-height: 1.25;
      font-weight: 900;
      color: var(--text-main);
      margin-bottom: 20px;
      letter-spacing: -1px;
    }

    .hero-title span {
      background: linear-gradient(135deg, #4f46e5 0%, #ec4899 50%, #f97316 100%);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
    }

    .hero-subtitle {
      font-size: 1.12rem;
      color: var(--text-muted);
      line-height: 1.7;
      margin-bottom: 32px;
      max-width: 780px;
      margin-left: auto;
      margin-right: auto;
    }

    .hero-buttons {
      display: flex;
      flex-wrap: wrap;
      justify-content: center;
      gap: 16px;
      margin-bottom: 45px;
    }

    .btn-hero-primary {
      background: linear-gradient(135deg, #f97316, #ec4899);
      color: #ffffff;
      font-size: 1.05rem;
      font-weight: 800;
      padding: 14px 34px;
      border-radius: 50px;
      box-shadow: 0 10px 25px rgba(249, 115, 22, 0.35);
    }

    .btn-hero-primary:hover {
      transform: translateY(-2px);
      box-shadow: 0 12px 30px rgba(236, 72, 153, 0.45);
      color: #ffffff;
    }

    .btn-hero-secondary {
      background: #ffffff;
      color: var(--text-main);
      border: 2px solid var(--border-color);
      font-size: 1.05rem;
      font-weight: 700;
      padding: 14px 32px;
      border-radius: 50px;
    }

    .btn-hero-secondary:hover {
      border-color: var(--color-primary);
      color: var(--color-primary);
      background: var(--bg-alt);
    }

    .hero-metrics-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 16px;
      margin-top: 10px;
    }

    .metric-card {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      padding: 20px 16px;
      box-shadow: var(--shadow-sm);
      border-top: 4px solid var(--color-primary);
      transition: all 0.25s ease;
    }

    .metric-card:nth-child(2) { border-top-color: var(--color-accent-pink); }
    .metric-card:nth-child(3) { border-top-color: var(--color-accent-cyan); }
    .metric-card:nth-child(4) { border-top-color: var(--color-accent-orange); }

    .metric-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-md);
    }

    .metric-num {
      font-size: 1.8rem;
      font-weight: 900;
      color: var(--text-main);
      margin-bottom: 4px;
    }

    .metric-text {
      font-size: 0.85rem;
      color: var(--text-light);
      font-weight: 600;
    }

    /* 通用章节规范 */
    .section-wrap {
      padding: 70px 0;
      border-bottom: 1px solid var(--border-color);
    }

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

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

    .section-tag {
      font-size: 0.82rem;
      font-weight: 800;
      text-transform: uppercase;
      letter-spacing: 1px;
      color: var(--color-accent-pink);
      background: rgba(236, 72, 153, 0.1);
      padding: 4px 12px;
      border-radius: 20px;
      display: inline-block;
      margin-bottom: 10px;
    }

    .section-title {
      font-size: 2rem;
      font-weight: 800;
      color: var(--text-main);
      margin-bottom: 12px;
    }

    .section-desc {
      font-size: 1rem;
      color: var(--text-muted);
      line-height: 1.6;
    }

    /* 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: 24px;
    }

    .standard-card {
      background: var(--bg-card);
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      padding: 28px;
      box-shadow: var(--shadow-sm);
      transition: all 0.3s ease;
      display: flex;
      flex-direction: column;
    }

    .standard-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
      border-color: rgba(79, 70, 229, 0.4);
    }

    .card-accent-strip {
      width: 44px;
      height: 6px;
      border-radius: 4px;
      background: linear-gradient(90deg, var(--color-primary), var(--color-accent-cyan));
      margin-bottom: 18px;
    }

    .card-title {
      font-size: 1.22rem;
      font-weight: 700;
      color: var(--text-main);
      margin-bottom: 12px;
    }

    .card-body {
      font-size: 0.94rem;
      color: var(--text-muted);
      line-height: 1.65;
      flex-grow: 1;
    }

    /* 模型矩阵胶囊 */
    .models-badge-wall {
      display: flex;
      flex-wrap: wrap;
      gap: 10px;
      justify-content: center;
      margin-top: 30px;
    }

    .model-chip {
      background: #ffffff;
      border: 1px solid var(--border-color);
      padding: 8px 18px;
      border-radius: 40px;
      font-size: 0.88rem;
      font-weight: 700;
      color: var(--text-main);
      box-shadow: var(--shadow-sm);
      transition: all 0.2s ease;
    }

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

    /* 对比评测高亮 */
    .eval-highlight-box {
      background: linear-gradient(135deg, #4f46e5 0%, #7c3aed 50%, #ec4899 100%);
      border-radius: var(--radius-lg);
      padding: 36px;
      color: #ffffff;
      margin-bottom: 30px;
      display: flex;
      flex-wrap: wrap;
      align-items: center;
      justify-content: space-between;
      gap: 20px;
    }

    .eval-score-num {
      font-size: 3.5rem;
      font-weight: 900;
      line-height: 1;
      color: #ffeb3b;
    }

    .eval-score-stars {
      font-size: 1.3rem;
      color: #ffeb3b;
      margin-bottom: 6px;
    }

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

    .table-custom {
      width: 100%;
      border-collapse: collapse;
      text-align: left;
      font-size: 0.94rem;
    }

    .table-custom th, .table-custom td {
      padding: 16px 20px;
      border-bottom: 1px solid var(--border-color);
    }

    .table-custom th {
      background: var(--bg-alt);
      font-weight: 800;
      color: var(--text-main);
    }

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

    .tag-win {
      background: rgba(16, 185, 129, 0.15);
      color: #047857;
      padding: 4px 10px;
      border-radius: 6px;
      font-weight: 700;
      font-size: 0.82rem;
    }

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

    .step-box {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      padding: 24px;
      position: relative;
      transition: transform 0.25s ease;
    }

    .step-box:hover {
      transform: translateY(-3px);
    }

    .step-badge {
      width: 36px;
      height: 36px;
      border-radius: 50%;
      background: var(--color-accent-orange);
      color: #ffffff;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 800;
      margin-bottom: 16px;
    }

    /* 案例图片展示容器 */
    .media-card-box {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
      display: flex;
      flex-direction: column;
    }

    .media-card-img-wrap {
      width: 100%;
      background: var(--bg-alt);
      overflow: hidden;
      aspect-ratio: 16 / 9;
      display: flex;
      align-items: center;
      justify-content: center;
    }

    .media-card-img-wrap.square-ratio {
      aspect-ratio: 1 / 1;
    }

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

    .media-card-box:hover .media-card-img-wrap img {
      transform: scale(1.03);
    }

    .media-card-info {
      padding: 20px;
      flex-grow: 1;
    }

    /* 评论区卡片 */
    .testimonial-card {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      padding: 24px;
      box-shadow: var(--shadow-sm);
      position: relative;
      display: flex;
      flex-direction: column;
      justify-content: space-between;
    }

    .testimonial-quote {
      font-size: 0.94rem;
      color: var(--text-muted);
      line-height: 1.6;
      margin-bottom: 16px;
      font-style: normal;
    }

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

    .user-avatar-initial {
      width: 40px;
      height: 40px;
      border-radius: 50%;
      background: linear-gradient(135deg, var(--color-primary), var(--color-accent-pink));
      color: #ffffff;
      font-weight: 800;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 0.95rem;
    }

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

    .user-meta-role {
      font-size: 0.8rem;
      color: var(--text-light);
    }

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

    .faq-item {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
    }

    .faq-question-btn {
      width: 100%;
      text-align: left;
      padding: 18px 24px;
      background: none;
      border: none;
      font-size: 1.02rem;
      font-weight: 700;
      color: var(--text-main);
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
    }

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

    .faq-icon-arrow {
      font-size: 1.2rem;
      transition: transform 0.3s ease;
      color: var(--color-primary);
    }

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

    .faq-answer-panel {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease, padding 0.3s ease;
      background: var(--bg-alt);
      padding: 0 24px;
    }

    .faq-item.active .faq-answer-panel {
      padding: 18px 24px;
      max-height: 300px;
    }

    .faq-answer-panel p {
      font-size: 0.94rem;
      color: var(--text-muted);
      line-height: 1.65;
    }

    /* 表单组件 */
    .form-wrapper-box {
      background: #ffffff;
      border: 2px solid var(--border-color);
      border-radius: var(--radius-lg);
      padding: 40px;
      box-shadow: var(--shadow-md);
      max-width: 800px;
      margin: 0 auto;
    }

    .form-group-row {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 18px;
      margin-bottom: 18px;
    }

    .form-field {
      display: flex;
      flex-direction: column;
      gap: 6px;
      margin-bottom: 18px;
    }

    .form-field label {
      font-size: 0.9rem;
      font-weight: 700;
      color: var(--text-main);
    }

    .form-input, .form-select, .form-textarea {
      width: 100%;
      padding: 12px 16px;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-sm);
      font-size: 0.95rem;
      color: var(--text-main);
      background: #ffffff;
      outline: none;
      transition: border-color 0.25s ease;
    }

    .form-input:focus, .form-select:focus, .form-textarea:focus {
      border-color: var(--color-primary);
      box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.15);
    }

    .form-submit-btn {
      width: 100%;
      padding: 15px;
      background: linear-gradient(135deg, var(--color-primary), var(--color-accent-pink));
      color: #ffffff;
      border: none;
      border-radius: var(--radius-sm);
      font-size: 1.05rem;
      font-weight: 800;
      cursor: pointer;
      box-shadow: 0 8px 20px rgba(79, 70, 229, 0.3);
      transition: all 0.25s ease;
    }

    .form-submit-btn:hover {
      transform: translateY(-2px);
      box-shadow: 0 12px 25px rgba(236, 72, 153, 0.4);
    }

    /* 资讯与友情链接 */
    .article-links-wrap {
      display: flex;
      flex-wrap: wrap;
      gap: 12px;
      margin-top: 20px;
    }

    .article-link-tag {
      background: #ffffff;
      border: 1px solid var(--border-color);
      padding: 8px 16px;
      border-radius: 30px;
      font-size: 0.88rem;
      color: var(--text-main);
      font-weight: 600;
    }

    .article-link-tag:hover {
      border-color: var(--color-accent-pink);
      color: var(--color-accent-pink);
    }

    /* 底部专属统一 */
    .site-footer {
      background: #ffffff;
      border-top: 2px solid var(--border-color);
      padding: 50px 0 30px;
      margin-top: auto;
      color: var(--text-main);
    }

    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1.2fr;
      gap: 30px;
      margin-bottom: 40px;
    }

    .footer-col h4 {
      font-size: 1.05rem;
      font-weight: 800;
      color: var(--text-main);
      margin-bottom: 16px;
    }

    .footer-col p {
      font-size: 0.9rem;
      color: var(--text-muted);
      line-height: 1.6;
      margin-bottom: 10px;
    }

    .footer-links-list {
      list-style: none;
      display: flex;
      flex-direction: column;
      gap: 8px;
    }

    .footer-links-list li a {
      font-size: 0.9rem;
      color: var(--text-muted);
    }

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

    .friend-links-box {
      border-top: 1px solid var(--border-color);
      padding: 20px 0;
      margin-bottom: 20px;
    }

    .friend-links-title {
      font-size: 0.9rem;
      font-weight: 700;
      color: var(--text-muted);
      margin-bottom: 10px;
    }

    .friend-links-flex {
      display: flex;
      flex-wrap: wrap;
      gap: 14px;
    }

    .friend-links-flex a {
      font-size: 0.85rem;
      color: var(--text-light);
    }

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

    .footer-bottom-bar {
      border-top: 1px solid var(--border-color);
      padding-top: 20px;
      text-align: center;
      font-size: 0.86rem;
      color: var(--text-light);
    }

    /* 悬浮客服面板 */
    .floating-contact-panel {
      position: fixed;
      right: 20px;
      bottom: 30px;
      z-index: 999;
      display: flex;
      flex-direction: column;
      align-items: flex-end;
      gap: 10px;
    }

    .floating-trigger-btn {
      width: 52px;
      height: 52px;
      border-radius: 50%;
      background: linear-gradient(135deg, var(--color-accent-pink), var(--color-primary));
      color: #ffffff;
      display: flex;
      align-items: center;
      justify-content: center;
      box-shadow: 0 6px 18px rgba(79, 70, 229, 0.4);
      cursor: pointer;
      border: none;
      font-size: 1.4rem;
      transition: transform 0.25s ease;
    }

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

    .floating-modal-card {
      display: none;
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      padding: 16px;
      box-shadow: var(--shadow-md);
      width: 220px;
      text-align: center;
    }

    .floating-modal-card.show {
      display: block;
    }

    .floating-modal-card img {
      width: 140px;
      height: 140px;
      margin: 0 auto 10px;
      display: block;
      border-radius: var(--radius-sm);
    }

    .floating-modal-card p {
      font-size: 0.82rem;
      color: var(--text-muted);
    }

    /* 响应式适配 */
    @media (max-width: 992px) {
      .grid-4, .hero-metrics-grid, .steps-wrapper {
        grid-template-columns: repeat(2, 1fr);
      }
      .grid-3 {
        grid-template-columns: repeat(2, 1fr);
      }
      .footer-grid {
        grid-template-columns: 1fr 1fr;
      }
    }

    @media (max-width: 768px) {
      .mobile-menu-btn {
        display: block;
      }
      .nav-links {
        display: none;
        position: absolute;
        top: 72px;
        left: 0;
        width: 100%;
        background: #ffffff;
        flex-direction: column;
        padding: 16px 20px;
        border-bottom: 2px solid var(--border-color);
        box-shadow: var(--shadow-md);
      }
      .nav-links.active {
        display: flex;
      }
      .nav-links li {
        width: 100%;
      }
      .nav-links li a {
        display: block;
        padding: 10px 0;
      }
      .hero-title {
        font-size: 1.85rem;
      }
      .hero-metrics-grid, .grid-3, .grid-2, .grid-4, .steps-wrapper {
        grid-template-columns: 1fr;
      }
      .form-group-row {
        grid-template-columns: 1fr;
      }
      .footer-grid {
        grid-template-columns: 1fr;
      }
      .form-wrapper-box {
        padding: 24px 16px;
      }
    }