/* roulang page: index */
:root {
      --bg-base: #0F172A;
      --bg-surface: #1E293B;
      --bg-card: #141E33;
      --bg-light: #F8F9FA;
      --text-main: #FFFFFF;
      --text-muted: #94A3B8;
      --text-dark: #0F172A;
      --text-dark-muted: #475569;
      --primary-teal: #0D9488;
      --primary-green: #10B981;
      --border-color: rgba(226, 232, 240, 0.12);
      --border-light: #E2E8F0;
      --radius-sm: 6px;
      --radius-md: 8px;
      --radius-lg: 12px;
      --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.1);
      --shadow-md: 0 4px 20px -2px rgba(15, 23, 42, 0.25);
      --transition: all 0.25s cubic-bezier(0.16, 1, 0.3, 1);
    }

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

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

    body {
      font-family: system-ui, -apple-system, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
      background-color: var(--bg-light);
      color: var(--text-dark);
      line-height: 1.8;
      letter-spacing: -0.01em;
      -webkit-font-smoothing: antialiased;
    }

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

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

    .container {
      width: 100%;
      max-width: 1240px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 24px;
      padding-right: 24px;
    }

    /* 顶部 Utility Bar */
    .utility-bar {
      background-color: #090D16;
      color: var(--text-muted);
      font-size: 0.8125rem;
      border-bottom: 1px solid rgba(255, 255, 255, 0.08);
      padding: 8px 0;
    }
    .utility-bar .container {
      display: flex;
      justify-content: space-between;
      align-items: center;
    }
    .utility-bar span {
      display: inline-flex;
      align-items: center;
      gap: 6px;
    }

    /* 吸顶导航 */
    .site-header {
      position: sticky;
      top: 0;
      z-index: 1000;
      background-color: rgba(255, 255, 255, 0.95);
      backdrop-filter: blur(8px);
      border-bottom: 1px solid var(--border-light);
      box-shadow: 0 2px 12px rgba(15, 23, 42, 0.04);
    }
    .header-inner {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 72px;
    }
    .brand-logo {
      display: flex;
      align-items: center;
      gap: 10px;
      font-size: 1.25rem;
      font-weight: 700;
      color: var(--text-dark);
    }
    .brand-logo-icon {
      width: 32px;
      height: 32px;
      background: linear-gradient(135deg, var(--primary-teal), var(--primary-green));
      border-radius: var(--radius-sm);
      display: flex;
      align-items: center;
      justify-content: center;
      color: #FFF;
      font-size: 1rem;
      font-weight: 800;
    }
    .nav-menu {
      display: flex;
      align-items: center;
      gap: 24px;
      list-style: none;
    }
    .nav-menu a {
      font-size: 0.9375rem;
      font-weight: 500;
      color: var(--text-dark-muted);
      padding: 6px 0;
      position: relative;
    }
    .nav-menu a:hover, .nav-menu a.active {
      color: var(--primary-teal);
    }
    .nav-menu a.active::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 100%;
      height: 2px;
      background-color: var(--primary-teal);
    }
    .header-cta {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      background-color: var(--primary-teal);
      color: #FFF;
      padding: 9px 20px;
      border-radius: var(--radius-sm);
      font-size: 0.875rem;
      font-weight: 600;
      border: 1px solid transparent;
      cursor: pointer;
    }
    .header-cta:hover {
      background-color: #0b7a6f;
      transform: translateY(-2px);
      box-shadow: 0 4px 12px rgba(13, 148, 136, 0.25);
    }

    /* 通用板块规范 */
    .section-wrap {
      padding: 88px 0;
      position: relative;
    }
    .section-dark {
      background-color: var(--bg-base);
      color: var(--text-main);
    }
    .section-alt {
      background-color: #F1F5F9;
    }
    .section-deep {
      background-color: #090D16;
      color: var(--text-main);
    }
    .section-header {
      margin-bottom: 48px;
    }
    .section-header.text-center {
      text-align: center;
    }
    .section-tag {
      display: inline-block;
      font-size: 0.75rem;
      font-weight: 700;
      text-transform: uppercase;
      letter-spacing: 0.05em;
      padding: 4px 12px;
      border-radius: 4px;
      background-color: rgba(13, 148, 136, 0.12);
      color: var(--primary-teal);
      margin-bottom: 12px;
    }
    .section-dark .section-tag, .section-deep .section-tag {
      background-color: rgba(16, 185, 129, 0.15);
      color: var(--primary-green);
    }
    .section-title {
      font-size: 2.125rem;
      font-weight: 700;
      line-height: 1.3;
      margin-bottom: 16px;
    }
    .section-desc {
      font-size: 1rem;
      color: var(--text-dark-muted);
      max-width: 75ch;
      line-height: 1.8;
    }
    .section-header.text-center .section-desc {
      margin-left: auto;
      margin-right: auto;
    }
    .section-dark .section-desc, .section-deep .section-desc {
      color: var(--text-muted);
    }

    /* 按钮组 */
    .btn-group {
      display: flex;
      flex-wrap: wrap;
      gap: 16px;
      align-items: center;
    }
    .btn-primary {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 12px 28px;
      background-color: var(--primary-teal);
      color: #FFF;
      font-size: 0.9375rem;
      font-weight: 600;
      border-radius: var(--radius-sm);
      border: 1px solid var(--primary-teal);
    }
    .btn-primary:hover {
      background-color: #0b7a6f;
      transform: translateY(-2px);
      box-shadow: 0 6px 16px rgba(13, 148, 136, 0.3);
    }
    .btn-outline {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 12px 28px;
      background-color: transparent;
      color: var(--text-main);
      font-size: 0.9375rem;
      font-weight: 600;
      border-radius: var(--radius-sm);
      border: 1px solid rgba(255, 255, 255, 0.25);
    }
    .btn-outline:hover {
      background-color: rgba(255, 255, 255, 0.08);
      border-color: #FFF;
      transform: translateY(-2px);
    }

    /* 1. Hero 矮版 + 竖屏主视感卡片 + 强 CTA */
    #hero {
      background: linear-gradient(180deg, #090D16 0%, #0F172A 100%);
      color: #FFF;
      padding: 72px 0;
      border-bottom: 1px solid rgba(255, 255, 255, 0.08);
    }
    .hero-grid {
      display: grid;
      grid-template-columns: 1.25fr 0.75fr;
      gap: 40px;
      align-items: center;
    }
    .hero-content h1 {
      font-size: 2.5rem;
      line-height: 1.25;
      font-weight: 800;
      margin-bottom: 20px;
      letter-spacing: -0.02em;
    }
    .hero-content h1 span {
      background: linear-gradient(90deg, #2DD4BF, #34D399);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
    }
    .hero-content p {
      font-size: 1.0625rem;
      color: var(--text-muted);
      line-height: 1.8;
      margin-bottom: 32px;
      max-width: 65ch;
    }
    .hero-badges {
      display: flex;
      flex-wrap: wrap;
      gap: 20px;
      margin-top: 36px;
      padding-top: 28px;
      border-top: 1px solid rgba(255, 255, 255, 0.1);
    }
    .badge-item {
      display: flex;
      flex-direction: column;
    }
    .badge-value {
      font-size: 1.35rem;
      font-weight: 800;
      color: var(--primary-green);
    }
    .badge-label {
      font-size: 0.8125rem;
      color: var(--text-muted);
    }
    /* 竖屏视频感视觉卡 */
    .hero-preview-vertical {
      position: relative;
      border-radius: var(--radius-md);
      overflow: hidden;
      border: 1px solid rgba(255, 255, 255, 0.15);
      background-color: var(--bg-surface);
      box-shadow: 0 16px 36px -4px rgba(0, 0, 0, 0.5);
      aspect-ratio: 9/12;
      max-width: 360px;
      margin: 0 auto;
    }
    .hero-preview-vertical img {
      width: 100%;
      height: 100%;
      object-fit: cover;
      opacity: 0.88;
    }
    .vertical-overlay {
      position: absolute;
      inset: 0;
      background: linear-gradient(180deg, transparent 40%, rgba(9, 13, 22, 0.95) 100%);
      display: flex;
      flex-direction: column;
      justify-content: flex-end;
      padding: 24px;
    }
    .vertical-tag {
      background-color: var(--primary-teal);
      color: #FFF;
      font-size: 0.6875rem;
      font-weight: 700;
      padding: 3px 8px;
      border-radius: 3px;
      align-self: flex-start;
      margin-bottom: 8px;
    }
    .vertical-title {
      font-size: 1.125rem;
      font-weight: 700;
      color: #FFF;
      margin-bottom: 6px;
    }
    .vertical-desc {
      font-size: 0.8125rem;
      color: var(--text-muted);
      line-height: 1.5;
    }

    /* 2. 品牌故事与工程积淀 (#story) */
    .story-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 48px;
      align-items: center;
    }
    .story-image {
      border-radius: var(--radius-md);
      overflow: hidden;
      border: 1px solid var(--border-light);
      box-shadow: var(--shadow-md);
    }
    .story-text h3 {
      font-size: 1.5rem;
      font-weight: 700;
      margin-bottom: 16px;
      color: var(--text-dark);
    }
    .story-text p {
      font-size: 0.9375rem;
      color: var(--text-dark-muted);
      margin-bottom: 16px;
    }

    /* 3. 系列导航入口卡 (#navigation-matrix) */
    .nav-grid-cards {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 20px;
    }
    .nav-card {
      background: #FFFFFF;
      border: 1px solid var(--border-light);
      border-radius: var(--radius-md);
      padding: 24px;
      transition: var(--transition);
      display: block;
    }
    .nav-card:hover {
      border-color: var(--primary-teal);
      transform: translateY(-3px);
      box-shadow: var(--shadow-md);
    }
    .nav-card-icon {
      width: 44px;
      height: 44px;
      background-color: rgba(13, 148, 136, 0.08);
      border-radius: var(--radius-sm);
      display: flex;
      align-items: center;
      justify-content: center;
      color: var(--primary-teal);
      font-size: 1.25rem;
      font-weight: 800;
      margin-bottom: 16px;
    }
    .nav-card h4 {
      font-size: 1.125rem;
      font-weight: 700;
      margin-bottom: 8px;
      color: var(--text-dark);
    }
    .nav-card p {
      font-size: 0.875rem;
      color: var(--text-dark-muted);
      line-height: 1.6;
    }

    /* 4. 痛点剖析 (#pain-points) */
    .pain-cards {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .pain-card {
      background-color: #FFFFFF;
      border: 1px solid var(--border-light);
      border-radius: var(--radius-md);
      padding: 32px 24px;
      position: relative;
      transition: var(--transition);
    }
    .pain-card:hover {
      border-color: #EF4444;
      transform: translateY(-2px);
      box-shadow: var(--shadow-md);
    }
    .pain-tag {
      color: #EF4444;
      font-size: 0.8125rem;
      font-weight: 700;
      margin-bottom: 12px;
      display: block;
    }
    .pain-card h4 {
      font-size: 1.25rem;
      font-weight: 700;
      margin-bottom: 12px;
      color: var(--text-dark);
    }
    .pain-card p {
      font-size: 0.875rem;
      color: var(--text-dark-muted);
      line-height: 1.7;
    }

    /* 5. 端到端全栈技术架构 (#overview) */
    .arch-box {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 40px;
      align-items: center;
    }
    .arch-diagram {
      background-color: var(--bg-card);
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      padding: 24px;
    }
    .arch-layer {
      border: 1px dashed rgba(255, 255, 255, 0.15);
      border-radius: var(--radius-sm);
      padding: 16px;
      margin-bottom: 16px;
      background: rgba(255, 255, 255, 0.02);
    }
    .arch-layer:last-child {
      margin-bottom: 0;
    }
    .arch-layer-title {
      font-size: 0.875rem;
      font-weight: 700;
      color: var(--primary-green);
      margin-bottom: 8px;
    }
    .arch-layer-items {
      display: flex;
      flex-wrap: wrap;
      gap: 8px;
    }
    .arch-chip {
      background: rgba(255, 255, 255, 0.08);
      padding: 4px 10px;
      border-radius: 4px;
      font-size: 0.75rem;
      color: var(--text-main);
    }
    .arch-text h3 {
      font-size: 1.75rem;
      font-weight: 700;
      margin-bottom: 16px;
      line-height: 1.35;
    }
    .arch-text p {
      font-size: 0.9375rem;
      color: var(--text-muted);
      margin-bottom: 20px;
      line-height: 1.8;
    }
    .verified-spec {
      background-color: rgba(13, 148, 136, 0.1);
      border-left: 3px solid var(--primary-teal);
      padding: 12px 16px;
      font-size: 0.875rem;
      color: #E2E8F0;
      border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
    }

    /* 6. 核心优势壁垒 6 卡栅格 (#features) */
    .features-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .feature-card {
      background-color: #FFFFFF;
      border: 1px solid var(--border-light);
      border-radius: var(--radius-md);
      padding: 28px;
      transition: var(--transition);
    }
    .feature-card:hover {
      border-color: var(--primary-teal);
      transform: translateY(-2px);
      box-shadow: var(--shadow-md);
    }
    .feature-num {
      font-size: 1.25rem;
      font-weight: 800;
      color: var(--primary-teal);
      margin-bottom: 12px;
    }
    .feature-card h4 {
      font-size: 1.125rem;
      font-weight: 700;
      margin-bottom: 10px;
      color: var(--text-dark);
    }
    .feature-card p {
      font-size: 0.875rem;
      color: var(--text-dark-muted);
      line-height: 1.7;
    }

    /* 7. 场景模型矩阵 爆款产品卡 (#products) */
    .products-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 28px;
    }
    .product-card {
      background: #FFFFFF;
      border: 1px solid var(--border-light);
      border-radius: var(--radius-md);
      overflow: hidden;
      display: flex;
      flex-direction: column;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
    }
    .product-card:hover {
      transform: translateY(-3px);
      border-color: var(--primary-teal);
      box-shadow: var(--shadow-md);
    }
    .product-thumb {
      height: 190px;
      overflow: hidden;
      position: relative;
    }
    .product-thumb img {
      width: 100%;
      height: 100%;
      object-fit: cover;
    }
    .product-body {
      padding: 24px;
      flex: 1;
      display: flex;
      flex-direction: column;
    }
    .product-body h4 {
      font-size: 1.25rem;
      font-weight: 700;
      margin-bottom: 10px;
      color: var(--text-dark);
    }
    .product-body p {
      font-size: 0.875rem;
      color: var(--text-dark-muted);
      margin-bottom: 16px;
      line-height: 1.6;
    }
    .product-specs {
      margin-top: auto;
      background: #F8F9FA;
      padding: 12px;
      border-radius: var(--radius-sm);
      border: 1px solid var(--border-light);
      font-size: 0.75rem;
      color: var(--text-dark-muted);
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 8px;
    }
    .product-specs div span {
      display: block;
      font-weight: 700;
      color: var(--text-dark);
    }

    /* 8. 工程师深色准则 (#philosophy) */
    .philosophy-inner {
      text-align: center;
      max-width: 860px;
      margin: 0 auto;
    }
    .code-console {
      background-color: #05080E;
      border: 1px solid rgba(255, 255, 255, 0.12);
      border-radius: var(--radius-md);
      padding: 24px;
      text-align: left;
      font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, monospace;
      font-size: 0.8125rem;
      color: #38BDF8;
      margin-top: 36px;
      line-height: 1.7;
      overflow-x: auto;
    }
    .code-console .comment {
      color: #64748B;
    }
    .code-console .keyword {
      color: #F43F5E;
    }
    .code-console .string {
      color: #10B981;
    }

    /* 9. 四阶工程落地路线 (#methodology) */
    .steps-timeline {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 20px;
      position: relative;
    }
    .step-card {
      background: #FFFFFF;
      border: 1px solid var(--border-light);
      border-radius: var(--radius-md);
      padding: 24px;
      position: relative;
    }
    .step-badge {
      width: 28px;
      height: 28px;
      border-radius: 50%;
      background-color: var(--primary-teal);
      color: #FFF;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 0.875rem;
      font-weight: 700;
      margin-bottom: 16px;
    }
    .step-card h4 {
      font-size: 1.0625rem;
      font-weight: 700;
      margin-bottom: 8px;
      color: var(--text-dark);
    }
    .step-card p {
      font-size: 0.8125rem;
      color: var(--text-dark-muted);
      line-height: 1.6;
      margin-bottom: 12px;
    }
    .step-deliverable {
      font-size: 0.75rem;
      background: #F1F5F9;
      padding: 6px 10px;
      border-radius: 4px;
      color: #334155;
    }

    /* 10. 会员权益与算力阶梯 (#tiers) */
    .tiers-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .tier-card {
      background: #FFFFFF;
      border: 1px solid var(--border-light);
      border-radius: var(--radius-md);
      padding: 32px 24px;
      display: flex;
      flex-direction: column;
      position: relative;
      transition: var(--transition);
    }
    .tier-card.active-tier {
      border: 2px solid var(--primary-teal);
      box-shadow: 0 8px 24px rgba(13, 148, 136, 0.15);
    }
    .tier-badge {
      position: absolute;
      top: -12px;
      right: 20px;
      background: var(--primary-teal);
      color: #FFF;
      font-size: 0.75rem;
      padding: 2px 10px;
      border-radius: 12px;
      font-weight: 700;
    }
    .tier-title {
      font-size: 1.25rem;
      font-weight: 700;
      margin-bottom: 8px;
    }
    .tier-desc {
      font-size: 0.875rem;
      color: var(--text-dark-muted);
      margin-bottom: 24px;
    }
    .tier-list {
      list-style: none;
      margin-bottom: 28px;
      display: flex;
      flex-direction: column;
      gap: 12px;
      font-size: 0.875rem;
      color: var(--text-dark);
    }
    .tier-list li::before {
      content: '✓';
      color: var(--primary-green);
      font-weight: bold;
      margin-right: 8px;
    }

    /* 11. 实测效能数据带 (#metrics) */
    .metrics-bar {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 32px;
      text-align: center;
    }
    .metric-item {
      padding: 16px;
    }
    .metric-number {
      font-size: 2.75rem;
      font-weight: 800;
      color: var(--primary-teal);
      line-height: 1.1;
      margin-bottom: 8px;
    }
    .metric-label {
      font-size: 0.9375rem;
      color: var(--text-dark-muted);
      font-weight: 500;
    }

    /* 12. 客户实践实录 (#cases) */
    .case-card {
      background: #FFFFFF;
      border: 1px solid var(--border-light);
      border-radius: var(--radius-md);
      overflow: hidden;
      display: grid;
      grid-template-columns: 1fr 1fr;
      box-shadow: var(--shadow-sm);
    }
    .case-media img {
      width: 100%;
      height: 100%;
      object-fit: cover;
    }
    .case-info {
      padding: 40px;
      display: flex;
      flex-direction: column;
      justify-content: center;
    }
    .case-tag {
      font-size: 0.75rem;
      color: var(--primary-teal);
      font-weight: 700;
      margin-bottom: 8px;
    }
    .case-info h4 {
      font-size: 1.5rem;
      font-weight: 700;
      margin-bottom: 16px;
      color: var(--text-dark);
    }
    .case-info p {
      font-size: 0.9375rem;
      color: var(--text-dark-muted);
      margin-bottom: 24px;
      line-height: 1.7;
    }
    .case-results {
      display: flex;
      gap: 24px;
      border-top: 1px solid var(--border-light);
      padding-top: 16px;
    }
    .result-stat-val {
      font-size: 1.25rem;
      font-weight: 700;
      color: var(--primary-green);
    }
    .result-stat-txt {
      font-size: 0.75rem;
      color: var(--text-dark-muted);
    }

    /* 13. 架构师信赖证言 (#testimonials) */
    .quotes-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .quote-card {
      background: #FFFFFF;
      border: 1px solid var(--border-light);
      border-radius: var(--radius-md);
      padding: 32px 24px;
      display: flex;
      flex-direction: column;
      justify-content: space-between;
    }
    .quote-body {
      font-size: 0.9375rem;
      color: #334155;
      line-height: 1.75;
      margin-bottom: 20px;
      font-style: italic;
    }
    .quote-author {
      display: flex;
      align-items: center;
      gap: 12px;
      border-top: 1px solid var(--border-light);
      padding-top: 16px;
    }
    .author-avatar {
      width: 42px;
      height: 42px;
      border-radius: 50%;
      background: #E2E8F0;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 700;
      color: #475569;
    }
    .author-name {
      font-size: 0.875rem;
      font-weight: 700;
      color: var(--text-dark);
    }
    .author-title {
      font-size: 0.75rem;
      color: var(--text-dark-muted);
    }

    /* 14. 技术资讯摘要 (#insights) */
    .insights-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .insight-card {
      background: #FFFFFF;
      border: 1px solid var(--border-light);
      border-radius: var(--radius-md);
      overflow: hidden;
      transition: var(--transition);
      display: flex;
      flex-direction: column;
    }
    .insight-card:hover {
      transform: translateY(-2px);
      box-shadow: var(--shadow-md);
      border-color: var(--primary-teal);
    }
    .insight-thumb {
      height: 160px;
      overflow: hidden;
    }
    .insight-thumb img {
      width: 100%;
      height: 100%;
      object-fit: cover;
    }
    .insight-body {
      padding: 20px;
      flex: 1;
      display: flex;
      flex-direction: column;
    }
    .insight-date {
      font-size: 0.75rem;
      color: #94A3B8;
      margin-bottom: 8px;
    }
    .insight-body h4 {
      font-size: 1.0625rem;
      font-weight: 700;
      margin-bottom: 10px;
      color: var(--text-dark);
    }
    .insight-body p {
      font-size: 0.8125rem;
      color: var(--text-dark-muted);
      line-height: 1.6;
      margin-bottom: 16px;
    }
    .insight-link {
      margin-top: auto;
      font-size: 0.8125rem;
      color: var(--primary-teal);
      font-weight: 600;
      display: inline-flex;
      align-items: center;
      gap: 4px;
    }

    /* 15. 企业级保障条 (#guarantee) */
    .guarantee-bar {
      background: #090D16;
      border: 1px solid rgba(255, 255, 255, 0.1);
      border-radius: var(--radius-md);
      padding: 32px;
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
      text-align: center;
    }
    .guarantee-item h4 {
      font-size: 1rem;
      font-weight: 700;
      color: #FFF;
      margin-bottom: 6px;
    }
    .guarantee-item p {
      font-size: 0.8125rem;
      color: var(--text-muted);
    }

    /* 16. 高频 FAQ 手风琴 (#faq) */
    .faq-container {
      max-width: 840px;
      margin: 0 auto;
    }
    .faq-item {
      background: #FFFFFF;
      border: 1px solid var(--border-light);
      border-radius: var(--radius-sm);
      margin-bottom: 12px;
      overflow: hidden;
    }
    .faq-item summary {
      padding: 18px 24px;
      font-size: 1rem;
      font-weight: 600;
      color: var(--text-dark);
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
      list-style: none;
    }
    .faq-item summary::-webkit-details-marker {
      display: none;
    }
    .faq-item summary::after {
      content: '+';
      font-size: 1.25rem;
      color: var(--primary-teal);
      font-weight: 700;
      transition: var(--transition);
    }
    .faq-item[open] summary::after {
      content: '−';
    }
    .faq-content {
      padding: 0 24px 20px 24px;
      font-size: 0.875rem;
      color: var(--text-dark-muted);
      line-height: 1.75;
    }

    /* 17. 进店/咨询收口行动表单 (#cta) */
    .cta-container {
      background: linear-gradient(135deg, #090D16 0%, #1E293B 100%);
      border-radius: var(--radius-lg);
      border: 1px solid rgba(255, 255, 255, 0.1);
      padding: 56px 48px;
      display: grid;
      grid-template-columns: 1.2fr 1fr;
      gap: 48px;
      align-items: center;
      color: #FFF;
    }
    .cta-text h3 {
      font-size: 2rem;
      font-weight: 700;
      margin-bottom: 16px;
      line-height: 1.3;
    }
    .cta-text p {
      font-size: 0.9375rem;
      color: var(--text-muted);
      margin-bottom: 24px;
      line-height: 1.8;
    }
    .cta-contact-box {
      background: rgba(255, 255, 255, 0.05);
      border: 1px solid rgba(255, 255, 255, 0.1);
      border-radius: var(--radius-sm);
      padding: 16px 20px;
      font-size: 0.875rem;
      color: #E2E8F0;
    }
    .cta-form {
      background: #FFFFFF;
      padding: 32px;
      border-radius: var(--radius-md);
      color: var(--text-dark);
      box-shadow: var(--shadow-md);
    }
    .cta-form h4 {
      font-size: 1.125rem;
      font-weight: 700;
      margin-bottom: 16px;
    }
    .form-group {
      margin-bottom: 14px;
    }
    .form-group label {
      display: block;
      font-size: 0.75rem;
      font-weight: 600;
      margin-bottom: 6px;
      color: #475569;
    }
    .form-group input, .form-group select {
      width: 100%;
      padding: 10px 14px;
      border: 1px solid var(--border-light);
      border-radius: var(--radius-sm);
      font-size: 0.875rem;
      outline: none;
      background: #F8F9FA;
    }
    .form-group input:focus, .form-group select:focus {
      border-color: var(--primary-teal);
      background: #FFF;
    }
    .form-submit {
      width: 100%;
      padding: 12px;
      background: var(--primary-teal);
      color: #FFF;
      border: none;
      border-radius: var(--radius-sm);
      font-size: 0.9375rem;
      font-weight: 700;
      cursor: pointer;
      transition: var(--transition);
      margin-top: 8px;
    }
    .form-submit:hover {
      background: #0b7a6f;
    }

    /* 页脚系统 */
    .site-footer {
      background-color: #090D16;
      color: #94A3B8;
      border-top: 1px solid rgba(255, 255, 255, 0.08);
      padding: 64px 0 32px 0;
      font-size: 0.875rem;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 1.5fr 1fr 1fr 1.2fr;
      gap: 40px;
      margin-bottom: 48px;
    }
    .footer-brand h4 {
      font-size: 1.25rem;
      color: #FFF;
      font-weight: 700;
      margin-bottom: 16px;
    }
    .footer-brand p {
      line-height: 1.7;
      margin-bottom: 16px;
      font-size: 0.8125rem;
    }
    .footer-col h5 {
      font-size: 0.9375rem;
      color: #FFF;
      font-weight: 600;
      margin-bottom: 16px;
    }
    .footer-links {
      list-style: none;
      display: flex;
      flex-direction: column;
      gap: 10px;
    }
    .footer-links a:hover {
      color: var(--primary-teal);
    }
    .footer-contact-list {
      list-style: none;
      display: flex;
      flex-direction: column;
      gap: 10px;
      font-size: 0.8125rem;
    }
    .footer-bottom {
      border-top: 1px solid rgba(255, 255, 255, 0.08);
      padding-top: 24px;
      display: flex;
      flex-wrap: wrap;
      justify-content: space-between;
      align-items: center;
      font-size: 0.75rem;
      color: #64748B;
    }
    .footer-bottom a {
      color: #64748B;
    }
    .footer-bottom a:hover {
      color: #94A3B8;
    }

    /* 响应式断点 */
    @media (max-width: 1024px) {
      .hero-grid {
        grid-template-columns: 1fr;
      }
      .hero-preview-vertical {
        max-width: 320px;
      }
      .story-grid, .arch-box, .case-card, .cta-container {
        grid-template-columns: 1fr;
      }
      .nav-grid-cards {
        grid-template-columns: repeat(2, 1fr);
      }
      .features-grid, .products-grid, .quotes-grid, .insights-grid, .tiers-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .steps-timeline, .guarantee-bar {
        grid-template-columns: repeat(2, 1fr);
      }
      .footer-grid {
        grid-template-columns: 1fr 1fr;
      }
    }

    @media (max-width: 768px) {
      .nav-menu, .utility-bar {
        display: none;
      }
      .section-wrap {
        padding: 56px 0;
      }
      .hero-content h1 {
        font-size: 1.875rem;
      }
      .section-title {
        font-size: 1.5rem;
      }
      .pain-cards, .features-grid, .products-grid, .tiers-grid, .quotes-grid, .insights-grid, .nav-grid-cards, .steps-timeline, .guarantee-bar {
        grid-template-columns: 1fr;
      }
      .metrics-bar {
        grid-template-columns: 1fr 1fr;
      }
      .case-info {
        padding: 24px;
      }
      .cta-container {
        padding: 32px 20px;
      }
      .footer-grid {
        grid-template-columns: 1fr;
      }
    }