/* roulang page: index */
:root {
      --color-primary: #0F2744;
      --color-primary-light: #1A3B66;
      --color-primary-dark: #0B1526;
      --color-accent: #E86A33;
      --color-accent-hover: #D45A25;
      --color-bg-base: #FFFFFF;
      --color-bg-alt: #F8F9FA;
      --color-bg-card: #FFFFFF;
      --color-text-main: #1E293B;
      --color-text-muted: #64748B;
      --color-border: #E2E8F0;
      --color-border-focus: #CBD5E1;
      --font-family-base: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
      --container-max-width: 1240px;
      --radius-sm: 6px;
      --radius-md: 10px;
      --radius-lg: 16px;
      --shadow-sm: 0 2px 4px rgba(15, 39, 68, 0.04);
      --shadow-md: 0 8px 20px -4px rgba(15, 39, 68, 0.08);
      --shadow-lg: 0 16px 32px -8px rgba(15, 39, 68, 0.12);
      --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    }

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

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

    body {
      font-family: var(--font-family-base);
      color: var(--color-text-main);
      background-color: var(--color-bg-base);
      line-height: 1.7;
      -webkit-font-smoothing: antialiased;
    }

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

    img {
      max-width: 100%;
      height: auto;
      display: block;
    }

    ul, ol {
      list-style: none;
    }

    .container {
      width: 100%;
      max-width: var(--container-max-width);
      margin-left: auto;
      margin-right: auto;
      padding-left: 24px;
      padding-right: 24px;
    }

    /* 顶部双行导航 */
    .site-header {
      position: sticky;
      top: 0;
      z-index: 1000;
      background: rgba(255, 255, 255, 0.95);
      backdrop-filter: blur(10px);
      box-shadow: 0 1px 0 var(--color-border);
    }

    .topbar {
      height: 36px;
      background: var(--color-primary-dark);
      color: #94A3B8;
      font-size: 0.8125rem;
      border-bottom: 1px solid rgba(255, 255, 255, 0.08);
    }

    .topbar .container {
      display: flex;
      justify-content: space-between;
      align-items: center;
      height: 100%;
    }

    .topbar-left, .topbar-right {
      display: flex;
      align-items: center;
      gap: 20px;
    }

    .topbar a:hover {
      color: #FFFFFF;
    }

    .main-nav {
      height: 72px;
      display: flex;
      align-items: center;
    }

    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
    }

    .brand-logo {
      display: flex;
      align-items: center;
      gap: 12px;
      font-size: 1.35rem;
      font-weight: 700;
      color: var(--color-primary);
      letter-spacing: -0.5px;
    }

    .brand-logo-icon {
      width: 38px;
      height: 38px;
      background: linear-gradient(135deg, var(--color-accent), #F97316);
      border-radius: var(--radius-sm);
      display: flex;
      align-items: center;
      justify-content: center;
      color: #FFFFFF;
      font-weight: 900;
      font-size: 1.1rem;
      box-shadow: 0 4px 10px rgba(232, 106, 51, 0.25);
    }

    .nav-menu {
      display: flex;
      align-items: center;
      gap: 32px;
    }

    .nav-item {
      font-size: 0.95rem;
      font-weight: 500;
      color: var(--color-text-main);
      padding: 6px 0;
      position: relative;
    }

    .nav-item:hover, .nav-item.active {
      color: var(--color-accent);
    }

    .nav-item::after {
      content: '';
      position: absolute;
      bottom: -2px;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--color-accent);
      transition: var(--transition);
    }

    .nav-item:hover::after, .nav-item.active::after {
      width: 100%;
    }

    .nav-cta {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 10px 22px;
      background: var(--color-accent);
      color: #FFFFFF;
      font-size: 0.925rem;
      font-weight: 600;
      border-radius: var(--radius-md);
      transition: var(--transition);
      box-shadow: 0 4px 14px rgba(232, 106, 51, 0.25);
      border: 1px solid transparent;
    }

    .nav-cta:hover {
      background: var(--color-accent-hover);
      box-shadow: 0 6px 20px rgba(232, 106, 51, 0.35);
      transform: translateY(-1px);
    }

    .mobile-menu-toggle {
      display: none;
      background: none;
      border: none;
      font-size: 1.5rem;
      color: var(--color-primary);
      cursor: pointer;
    }

    /* 通用板块与排版系统 */
    .section-wrap {
      padding: 96px 0;
      position: relative;
    }

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

    .section-bg-dark {
      background-color: var(--color-primary-dark);
      color: #F8FAFC;
    }

    .section-header {
      margin-bottom: 56px;
    }

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

    .section-badge {
      display: inline-block;
      padding: 4px 14px;
      background: rgba(232, 106, 51, 0.1);
      color: var(--color-accent);
      font-size: 0.825rem;
      font-weight: 600;
      letter-spacing: 0.5px;
      border-radius: 20px;
      margin-bottom: 14px;
    }

    .section-badge-light {
      background: rgba(255, 255, 255, 0.12);
      color: #FED7AA;
    }

    .section-title {
      font-size: 2.15rem;
      font-weight: 700;
      line-height: 1.3;
      color: var(--color-primary);
      margin-bottom: 16px;
      letter-spacing: -0.5px;
    }

    .section-bg-dark .section-title {
      color: #FFFFFF;
    }

    .section-desc {
      font-size: 1.05rem;
      color: var(--color-text-muted);
      line-height: 1.75;
    }

    .section-bg-dark .section-desc {
      color: #94A3B8;
    }

    .btn-primary {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 14px 28px;
      background: var(--color-accent);
      color: #FFFFFF;
      font-weight: 600;
      border-radius: var(--radius-md);
      transition: var(--transition);
      box-shadow: 0 4px 14px rgba(232, 106, 51, 0.28);
    }

    .btn-primary:hover {
      background: var(--color-accent-hover);
      transform: translateY(-2px);
      box-shadow: 0 8px 24px rgba(232, 106, 51, 0.35);
    }

    .btn-secondary {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 14px 28px;
      background: transparent;
      color: var(--color-primary);
      border: 1px solid var(--color-border);
      font-weight: 600;
      border-radius: var(--radius-md);
      transition: var(--transition);
    }

    .btn-secondary:hover {
      border-color: var(--color-primary);
      background: rgba(15, 39, 68, 0.04);
      transform: translateY(-2px);
    }

    /* 1. Hero 知识付费主推卡式 */
    .hero-section {
      padding: 80px 0 100px;
      background: linear-gradient(180deg, #F8F9FA 0%, #FFFFFF 100%);
      border-bottom: 1px solid var(--color-border);
      position: relative;
      overflow: hidden;
    }

    .hero-grid {
      display: grid;
      grid-template-columns: 1.15fr 0.85fr;
      gap: 56px;
      align-items: center;
    }

    .hero-content h1 {
      font-size: 2.75rem;
      font-weight: 800;
      line-height: 1.25;
      color: var(--color-primary);
      margin-bottom: 24px;
      letter-spacing: -0.8px;
    }

    .hero-desc {
      font-size: 1.125rem;
      color: #475569;
      line-height: 1.8;
      margin-bottom: 36px;
    }

    .hero-actions {
      display: flex;
      gap: 16px;
      align-items: center;
      margin-bottom: 40px;
      flex-wrap: wrap;
    }

    .hero-trust-badges {
      display: flex;
      gap: 28px;
      padding-top: 28px;
      border-top: 1px solid var(--color-border);
    }

    .trust-item strong {
      display: block;
      font-size: 1.35rem;
      font-weight: 700;
      color: var(--color-primary);
    }

    .trust-item span {
      font-size: 0.85rem;
      color: var(--color-text-muted);
    }

    .hero-card {
      background: #FFFFFF;
      border-radius: var(--radius-lg);
      border: 1px solid var(--color-border);
      box-shadow: var(--shadow-lg);
      overflow: hidden;
      position: relative;
    }

    .hero-card-img-wrap {
      position: relative;
      height: 240px;
      overflow: hidden;
    }

    .hero-card-img-wrap img {
      width: 100%;
      height: 100%;
      object-fit: cover;
      transition: transform 0.6s ease;
    }

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

    .hero-card-badge {
      position: absolute;
      top: 16px;
      left: 16px;
      background: rgba(15, 39, 68, 0.85);
      backdrop-filter: blur(4px);
      color: #FFFFFF;
      font-size: 0.75rem;
      font-weight: 600;
      padding: 4px 10px;
      border-radius: var(--radius-sm);
    }

    .hero-card-body {
      padding: 28px;
    }

    .hero-card-title {
      font-size: 1.35rem;
      font-weight: 700;
      color: var(--color-primary);
      margin-bottom: 12px;
      line-height: 1.4;
    }

    .hero-card-tags {
      display: flex;
      gap: 8px;
      margin-bottom: 18px;
    }

    .tag-item {
      font-size: 0.75rem;
      padding: 3px 8px;
      background: var(--color-bg-alt);
      color: var(--color-text-muted);
      border-radius: 4px;
      border: 1px solid #E2E8F0;
    }

    .hero-card-meta {
      display: flex;
      justify-content: space-between;
      align-items: center;
      padding-top: 18px;
      border-top: 1px solid #F1F5F9;
    }

    .course-price-wrap {
      display: flex;
      align-items: baseline;
      gap: 8px;
    }

    .course-price {
      font-size: 1.5rem;
      font-weight: 700;
      color: var(--color-accent);
    }

    .course-origin-price {
      font-size: 0.875rem;
      color: #94A3B8;
      text-decoration: line-through;
    }

    /* 2. 客户案例 / 成果展示 */
    .case-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 32px;
    }

    .case-card {
      background: #FFFFFF;
      border: 1px solid var(--color-border);
      border-radius: var(--radius-md);
      padding: 32px;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
      display: flex;
      flex-direction: column;
      justify-content: space-between;
    }

    .case-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-md);
      border-color: #CBD5E1;
    }

    .case-user-header {
      display: flex;
      align-items: center;
      gap: 14px;
      margin-bottom: 18px;
    }

    .user-avatar-text {
      width: 46px;
      height: 46px;
      border-radius: 50%;
      background: var(--color-primary-light);
      color: #FFFFFF;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 700;
      font-size: 1.1rem;
    }

    .case-author-name {
      font-weight: 700;
      font-size: 1.05rem;
      color: var(--color-primary);
    }

    .case-author-title {
      font-size: 0.8125rem;
      color: var(--color-text-muted);
    }

    .case-body-text {
      font-size: 0.95rem;
      color: #475569;
      line-height: 1.7;
      margin-bottom: 24px;
    }

    .case-achievement-tag {
      background: #EFF6FF;
      color: #1D4ED8;
      font-size: 0.8125rem;
      font-weight: 600;
      padding: 6px 12px;
      border-radius: var(--radius-sm);
      display: inline-block;
    }

    /* 3. 结果数据统计横幅 */
    .stats-strip {
      background: var(--color-primary);
      color: #FFFFFF;
      padding: 64px 0;
    }

    .stats-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 32px;
      text-align: center;
    }

    .stat-number {
      font-size: 2.85rem;
      font-weight: 800;
      color: #FFFFFF;
      line-height: 1.1;
      margin-bottom: 8px;
      font-feature-settings: "tnum";
    }

    .stat-number span {
      color: var(--color-accent);
      font-size: 1.75rem;
      margin-left: 2px;
    }

    .stat-label {
      font-size: 0.95rem;
      color: #94A3B8;
      font-weight: 500;
    }

    /* 4. 前后对比区 (传统自学 vs 在线教育平台体系化培养) */
    .comparison-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 32px;
    }

    .comparison-card {
      border-radius: var(--radius-lg);
      padding: 40px;
      border: 1px solid var(--color-border);
      position: relative;
    }

    .comparison-card.card-negative {
      background: #FFFBFB;
      border-color: #FED7D7;
    }

    .comparison-card.card-positive {
      background: #F0FDF4;
      border-color: #BBF7D0;
      box-shadow: var(--shadow-md);
    }

    .comparison-header {
      display: flex;
      align-items: center;
      gap: 12px;
      margin-bottom: 24px;
    }

    .comparison-title {
      font-size: 1.4rem;
      font-weight: 700;
    }

    .card-negative .comparison-title {
      color: #991B1B;
    }

    .card-positive .comparison-title {
      color: #166534;
    }

    .comparison-list li {
      display: flex;
      align-items: flex-start;
      gap: 12px;
      font-size: 0.95rem;
      line-height: 1.65;
      margin-bottom: 18px;
    }

    .card-negative .comparison-list li {
      color: #7F1D1D;
    }

    .card-positive .comparison-list li {
      color: #14532D;
    }

    .point-icon {
      font-weight: 700;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      width: 22px;
      height: 22px;
      border-radius: 50%;
      flex-shrink: 0;
      margin-top: 2px;
      font-size: 0.8rem;
    }

    .card-negative .point-icon {
      background: #FEE2E2;
      color: #DC2626;
    }

    .card-positive .point-icon {
      background: #DCFCE7;
      color: #16A34A;
    }

    /* 5. 方法说明：科学教学闭环与四步学习法 */
    .steps-flow-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
      position: relative;
    }

    .step-item-card {
      background: #FFFFFF;
      border: 1px solid var(--color-border);
      border-radius: var(--radius-md);
      padding: 32px 24px;
      position: relative;
      transition: var(--transition);
    }

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

    .step-index-badge {
      width: 44px;
      height: 44px;
      background: var(--color-primary);
      color: #FFFFFF;
      font-size: 1.15rem;
      font-weight: 700;
      border-radius: var(--radius-sm);
      display: flex;
      align-items: center;
      justify-content: center;
      margin-bottom: 20px;
    }

    .step-name {
      font-size: 1.2rem;
      font-weight: 700;
      color: var(--color-primary);
      margin-bottom: 12px;
    }

    .step-desc {
      font-size: 0.9rem;
      color: var(--color-text-muted);
      line-height: 1.7;
    }

    /* 6. 行业痛点与学习壁垒洞察 */
    .painpoint-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 28px;
    }

    .painpoint-card {
      background: #FFFFFF;
      padding: 36px 30px;
      border-radius: var(--radius-md);
      border: 1px solid var(--color-border);
      border-top: 4px solid var(--color-accent);
      box-shadow: var(--shadow-sm);
    }

    .painpoint-tag {
      font-size: 0.8125rem;
      font-weight: 600;
      color: var(--color-accent);
      text-transform: uppercase;
      margin-bottom: 12px;
      display: block;
    }

    .painpoint-title {
      font-size: 1.25rem;
      font-weight: 700;
      color: var(--color-primary);
      margin-bottom: 14px;
    }

    .painpoint-content {
      font-size: 0.925rem;
      color: #64748B;
      line-height: 1.7;
    }

    /* 7. 平台技术架构与权威标准 */
    .arch-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 56px;
      align-items: center;
    }

    .arch-image-wrap {
      border-radius: var(--radius-lg);
      overflow: hidden;
      box-shadow: var(--shadow-lg);
      border: 1px solid var(--color-border);
    }

    .arch-features-list {
      margin-top: 28px;
    }

    .arch-feature-item {
      display: flex;
      gap: 16px;
      margin-bottom: 24px;
    }

    .arch-feature-icon {
      width: 40px;
      height: 40px;
      border-radius: 8px;
      background: rgba(15, 39, 68, 0.08);
      color: var(--color-primary);
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 700;
      flex-shrink: 0;
    }

    .arch-feature-title {
      font-size: 1.125rem;
      font-weight: 700;
      color: var(--color-primary);
      margin-bottom: 6px;
    }

    .arch-feature-text {
      font-size: 0.925rem;
      color: var(--color-text-muted);
      line-height: 1.65;
    }

    /* 8. 核心优势六维矩阵 */
    .matrix-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 28px;
    }

    .matrix-card {
      background: #FFFFFF;
      padding: 32px;
      border-radius: var(--radius-md);
      border: 1px solid var(--color-border);
      transition: var(--transition);
    }

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

    .matrix-icon-badge {
      width: 48px;
      height: 48px;
      border-radius: var(--radius-sm);
      background: #F1F5F9;
      color: var(--color-primary);
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 700;
      font-size: 1.2rem;
      margin-bottom: 20px;
    }

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

    .matrix-desc {
      font-size: 0.925rem;
      color: var(--color-text-muted);
      line-height: 1.7;
    }

    /* 9. 体系化专业课程展台 */
    .courses-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 32px;
    }

    .course-card {
      background: #FFFFFF;
      border-radius: var(--radius-lg);
      border: 1px solid var(--color-border);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
      display: flex;
      flex-direction: column;
    }

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

    .course-card-cover {
      height: 200px;
      position: relative;
      overflow: hidden;
    }

    .course-card-cover img {
      width: 100%;
      height: 100%;
      object-fit: cover;
      transition: transform 0.5s ease;
    }

    .course-card:hover .course-card-cover img {
      transform: scale(1.05);
    }

    .course-category-tag {
      position: absolute;
      top: 14px;
      left: 14px;
      background: rgba(15, 39, 68, 0.85);
      color: #FFFFFF;
      font-size: 0.75rem;
      padding: 4px 10px;
      border-radius: var(--radius-sm);
      font-weight: 600;
    }

    .course-card-content {
      padding: 24px;
      flex-grow: 1;
      display: flex;
      flex-direction: column;
      justify-content: space-between;
    }

    .course-card-title {
      font-size: 1.25rem;
      font-weight: 700;
      color: var(--color-primary);
      margin-bottom: 10px;
      line-height: 1.4;
    }

    .course-card-desc {
      font-size: 0.9rem;
      color: var(--color-text-muted);
      line-height: 1.65;
      margin-bottom: 18px;
    }

    .course-specs {
      display: flex;
      gap: 16px;
      font-size: 0.825rem;
      color: #64748B;
      padding: 12px 0;
      border-top: 1px dashed var(--color-border);
      border-bottom: 1px dashed var(--color-border);
      margin-bottom: 18px;
    }

    .course-footer {
      display: flex;
      align-items: center;
      justify-content: space-between;
    }

    .course-fee {
      font-size: 1.35rem;
      font-weight: 800;
      color: var(--color-accent);
    }

    .btn-card-action {
      padding: 8px 16px;
      background: var(--color-primary);
      color: #FFFFFF;
      font-size: 0.875rem;
      font-weight: 600;
      border-radius: var(--radius-sm);
    }

    .btn-card-action:hover {
      background: var(--color-accent);
    }

    /* 10. 多元学习场景与适用人群分流 */
    .persona-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 32px;
    }

    .persona-card {
      background: #FFFFFF;
      border: 1px solid var(--color-border);
      border-radius: var(--radius-md);
      padding: 36px 28px;
      text-align: center;
      transition: var(--transition);
    }

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

    .persona-icon {
      width: 60px;
      height: 60px;
      background: rgba(232, 106, 51, 0.1);
      color: var(--color-accent);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 1.5rem;
      font-weight: 700;
      margin: 0 auto 20px;
    }

    .persona-title {
      font-size: 1.3rem;
      font-weight: 700;
      color: var(--color-primary);
      margin-bottom: 12px;
    }

    .persona-desc {
      font-size: 0.925rem;
      color: var(--color-text-muted);
      line-height: 1.7;
      margin-bottom: 20px;
    }

    .persona-benefits {
      text-align: left;
      border-top: 1px solid #F1F5F9;
      padding-top: 18px;
    }

    .persona-benefits li {
      font-size: 0.85rem;
      color: #475569;
      margin-bottom: 8px;
      display: flex;
      align-items: center;
      gap: 8px;
    }

    .persona-benefits li::before {
      content: '✓';
      color: #16A34A;
      font-weight: 700;
    }

    /* 11. 在线教育行业洞察与学习指南资讯区 */
    .news-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 32px;
    }

    .news-card {
      background: #FFFFFF;
      border: 1px solid var(--color-border);
      border-radius: var(--radius-md);
      overflow: hidden;
      display: flex;
      flex-direction: column;
      transition: var(--transition);
    }

    .news-card:hover {
      border-color: #CBD5E1;
      box-shadow: var(--shadow-md);
      transform: translateY(-4px);
    }

    .news-card-img {
      height: 180px;
      overflow: hidden;
    }

    .news-card-img img {
      width: 100%;
      height: 100%;
      object-fit: cover;
      transition: transform 0.5s ease;
    }

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

    .news-card-body {
      padding: 24px;
      display: flex;
      flex-direction: column;
      flex-grow: 1;
    }

    .news-meta {
      font-size: 0.8125rem;
      color: #94A3B8;
      margin-bottom: 10px;
      display: flex;
      gap: 12px;
    }

    .news-title {
      font-size: 1.15rem;
      font-weight: 700;
      color: var(--color-primary);
      margin-bottom: 10px;
      line-height: 1.45;
    }

    .news-excerpt {
      font-size: 0.875rem;
      color: var(--color-text-muted);
      line-height: 1.65;
      margin-bottom: 18px;
      flex-grow: 1;
    }

    .news-link {
      font-size: 0.875rem;
      font-weight: 600;
      color: var(--color-accent);
      display: inline-flex;
      align-items: center;
      gap: 4px;
    }

    /* 12. 平台选型与学习疑问 FAQ */
    .faq-wrapper {
      max-width: 860px;
      margin: 0 auto;
    }

    .faq-item {
      background: #FFFFFF;
      border: 1px solid var(--color-border);
      border-radius: var(--radius-md);
      margin-bottom: 16px;
      overflow: hidden;
      transition: var(--transition);
    }

    .faq-item:hover {
      border-color: #CBD5E1;
    }

    .faq-question {
      padding: 22px 28px;
      font-size: 1.1rem;
      font-weight: 700;
      color: var(--color-primary);
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
      user-select: none;
    }

    .faq-icon-cross {
      font-size: 1.25rem;
      color: var(--color-accent);
      transition: transform 0.3s ease;
    }

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

    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s ease, padding 0.35s ease;
      background: #FAFAFA;
      color: #475569;
      font-size: 0.95rem;
      line-height: 1.75;
      padding: 0 28px;
    }

    .faq-item.active .faq-answer {
      max-height: 200px;
      padding: 0 28px 22px;
    }

    /* 13. 底部咨询与转化预约表单 */
    .cta-container {
      background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-dark) 100%);
      border-radius: var(--radius-lg);
      padding: 64px 48px;
      color: #FFFFFF;
      display: grid;
      grid-template-columns: 1.1fr 0.9fr;
      gap: 48px;
      align-items: center;
      box-shadow: var(--shadow-lg);
    }

    .cta-text h2 {
      font-size: 2.2rem;
      font-weight: 800;
      line-height: 1.3;
      margin-bottom: 16px;
      letter-spacing: -0.5px;
    }

    .cta-text p {
      font-size: 1.05rem;
      color: #CBD5E1;
      line-height: 1.75;
      margin-bottom: 24px;
    }

    .cta-form {
      background: #FFFFFF;
      padding: 32px;
      border-radius: var(--radius-md);
      box-shadow: 0 10px 25px rgba(0, 0, 0, 0.2);
    }

    .form-group {
      margin-bottom: 18px;
    }

    .form-label {
      display: block;
      font-size: 0.875rem;
      font-weight: 600;
      color: var(--color-primary);
      margin-bottom: 6px;
    }

    .form-input, .form-select {
      width: 100%;
      height: 46px;
      padding: 0 14px;
      border: 1px solid var(--color-border);
      border-radius: var(--radius-sm);
      font-size: 0.925rem;
      color: var(--color-text-main);
      outline: none;
      transition: var(--transition);
      background-color: #FFFFFF;
    }

    .form-input:focus, .form-select:focus {
      border-color: var(--color-accent);
      box-shadow: 0 0 0 3px rgba(232, 106, 51, 0.15);
    }

    .form-btn-submit {
      width: 100%;
      height: 48px;
      background: var(--color-accent);
      color: #FFFFFF;
      font-size: 1rem;
      font-weight: 700;
      border: none;
      border-radius: var(--radius-sm);
      cursor: pointer;
      transition: var(--transition);
      margin-top: 8px;
    }

    .form-btn-submit:hover {
      background: var(--color-accent-hover);
    }

    .form-tips {
      font-size: 0.75rem;
      color: #94A3B8;
      text-align: center;
      margin-top: 12px;
    }

    /* 底部页脚 */
    .site-footer {
      background: #060D17;
      color: #94A3B8;
      padding: 80px 0 32px;
      font-size: 0.9rem;
      border-top: 1px solid rgba(255, 255, 255, 0.06);
    }

    .footer-grid {
      display: grid;
      grid-template-columns: 1.4fr 1fr 1fr 1.2fr;
      gap: 48px;
      margin-bottom: 64px;
    }

    .footer-brand {
      color: #FFFFFF;
      font-size: 1.35rem;
      font-weight: 700;
      margin-bottom: 16px;
      display: inline-block;
    }

    .footer-intro {
      line-height: 1.7;
      margin-bottom: 20px;
    }

    .footer-title {
      font-size: 1.05rem;
      font-weight: 700;
      color: #FFFFFF;
      margin-bottom: 20px;
    }

    .footer-links li {
      margin-bottom: 12px;
    }

    .footer-links a {
      color: #94A3B8;
    }

    .footer-links a:hover {
      color: #FFFFFF;
      padding-left: 4px;
    }

    .footer-contact-item {
      display: flex;
      flex-direction: column;
      margin-bottom: 14px;
    }

    .footer-contact-label {
      font-size: 0.75rem;
      color: #64748B;
      text-transform: uppercase;
    }

    .footer-contact-val {
      color: #E2E8F0;
      font-weight: 500;
      margin-top: 2px;
    }

    .footer-bottom {
      padding-top: 32px;
      border-top: 1px solid rgba(255, 255, 255, 0.08);
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-size: 0.8125rem;
      color: #64748B;
    }

    .footer-bottom-links {
      display: flex;
      gap: 20px;
    }

    .footer-bottom-links a:hover {
      color: #CBD5E1;
    }

    /* 响应式断点处理 */
    @media (max-width: 1024px) {
      .hero-grid, .cta-container, .arch-grid {
        grid-template-columns: 1fr;
        gap: 40px;
      }
      .case-grid, .matrix-grid, .courses-grid, .persona-grid, .news-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .stats-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 40px 24px;
      }
      .steps-flow-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .footer-grid {
        grid-template-columns: repeat(2, 1fr);
      }
    }

    @media (max-width: 768px) {
      .topbar {
        display: none;
      }
      .mobile-menu-toggle {
        display: block;
      }
      .nav-menu {
        display: none;
        position: absolute;
        top: 72px;
        left: 0;
        right: 0;
        background: #FFFFFF;
        flex-direction: column;
        padding: 24px;
        box-shadow: 0 10px 20px rgba(0,0,0,0.1);
        border-bottom: 1px solid var(--color-border);
      }
      .nav-menu.show {
        display: flex;
      }
      .nav-cta {
        display: none;
      }
      .hero-content h1 {
        font-size: 2.1rem;
      }
      .section-title {
        font-size: 1.75rem;
      }
      .section-wrap {
        padding: 60px 0;
      }
      .case-grid, .matrix-grid, .courses-grid, .persona-grid, .news-grid, .painpoint-grid, .steps-flow-grid, .comparison-grid {
        grid-template-columns: 1fr;
      }
      .stats-grid {
        grid-template-columns: 1fr 1fr;
      }
      .cta-container {
        padding: 36px 20px;
      }
      .footer-grid {
        grid-template-columns: 1fr;
        gap: 36px;
      }
      .footer-bottom {
        flex-direction: column;
        gap: 16px;
        text-align: center;
      }
    }