/* roulang page: index */
:root {
      --primary: #165DFF;
      --primary-hover: #0E42D2;
      --primary-light: #E8F3FF;
      --accent: #00B42A;
      --dark-bg: #0D1117;
      --dark-card: #181E25;
      --text-main: #1D2129;
      --text-secondary: #4E5969;
      --text-muted: #86909C;
      --text-white: #F7F9FC;
      --border-color: #E5E8EF;
      --border-dark: #2A313C;
      --bg-page: #F7F9FC;
      --bg-card: #FFFFFF;
      --radius: 6px;
      --radius-sm: 4px;
      --shadow-sm: 0 2px 6px rgba(0, 0, 0, 0.04);
      --shadow-hover: 0 8px 24px rgba(22, 93, 255, 0.1);
      --container-max: 1280px;
      --transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
    }

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

    html {
      scroll-behavior: smooth;
      font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
      background-color: var(--bg-page);
      color: var(--text-main);
      font-size: 16px;
      line-height: 1.65;
    }

    body {
      overflow-x: hidden;
      width: 100%;
    }

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

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

    .container {
      max-width: var(--container-max);
      margin: 0 auto;
      padding: 0 24px;
    }

    .section-spacing {
      padding: 96px 0;
    }

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

    .section-alt {
      background-color: #FFFFFF;
    }

    .section-header {
      margin-bottom: 56px;
    }
    .section-header.center {
      text-align: center;
      max-width: 840px;
      margin-left: auto;
      margin-right: auto;
    }

    .eyebrow {
      display: inline-flex;
      align-items: center;
      gap: 8px;
      font-size: 0.875rem;
      font-weight: 600;
      color: var(--primary);
      text-transform: uppercase;
      letter-spacing: 0.08em;
      margin-bottom: 12px;
    }
    .section-dark .eyebrow {
      color: #4080FF;
    }

    .section-title {
      font-size: 2.25rem;
      font-weight: 700;
      line-height: 1.3;
      letter-spacing: -0.02em;
      color: var(--text-main);
      margin-bottom: 16px;
    }
    .section-dark .section-title {
      color: #FFFFFF;
    }

    .section-desc {
      font-size: 1rem;
      color: var(--text-secondary);
      line-height: 1.75;
    }
    .section-dark .section-desc {
      color: #A4B2C6;
    }

    /* 按钮规范 */
    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 12px 28px;
      font-size: 0.95rem;
      font-weight: 600;
      border-radius: var(--radius-sm);
      cursor: pointer;
      transition: var(--transition);
      border: 1px solid transparent;
      gap: 8px;
      line-height: 1.2;
    }
    .btn-primary {
      background-color: var(--primary);
      color: #FFFFFF;
    }
    .btn-primary:hover {
      background-color: var(--primary-hover);
      box-shadow: 0 4px 14px rgba(22, 93, 255, 0.3);
    }
    .btn-outline {
      background-color: transparent;
      color: var(--text-main);
      border-color: var(--border-color);
    }
    .btn-outline:hover {
      background-color: #FFFFFF;
      border-color: var(--primary);
      color: var(--primary);
    }
    .btn-outline-white {
      background-color: transparent;
      color: #FFFFFF;
      border-color: rgba(255, 255, 255, 0.3);
    }
    .btn-outline-white:hover {
      background-color: rgba(255, 255, 255, 0.1);
      border-color: #FFFFFF;
    }

    /* 顶部通栏 */
    .topbar {
      background-color: #F2F3F5;
      font-size: 0.8125rem;
      color: var(--text-secondary);
      border-bottom: 1px solid var(--border-color);
      padding: 8px 0;
    }
    .topbar-content {
      display: flex;
      justify-content: space-between;
      align-items: center;
    }
    .topbar-items {
      display: flex;
      gap: 24px;
      align-items: center;
    }

    /* 主导航 */
    .site-header {
      position: sticky;
      top: 0;
      z-index: 100;
      background: rgba(255, 255, 255, 0.95);
      backdrop-filter: blur(12px);
      border-bottom: 1px solid var(--border-color);
    }
    .navbar {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 72px;
    }
    .brand-logo {
      display: flex;
      align-items: center;
      gap: 12px;
      font-size: 1.25rem;
      font-weight: 700;
      color: var(--text-main);
    }
    .logo-badge {
      background: var(--primary);
      color: #FFFFFF;
      padding: 4px 8px;
      border-radius: var(--radius-sm);
      font-size: 0.8rem;
      font-weight: 600;
    }
    .nav-links {
      display: flex;
      gap: 32px;
      align-items: center;
      list-style: none;
    }
    .nav-links a {
      font-size: 0.95rem;
      font-weight: 500;
      color: var(--text-main);
    }
    .nav-links a:hover {
      color: var(--primary);
    }
    .mobile-toggle {
      display: none;
      background: none;
      border: none;
      font-size: 1.5rem;
      cursor: pointer;
      color: var(--text-main);
    }

    /* 1. 首屏Banner (#hero) */
    .hero-section {
      position: relative;
      background-color: var(--dark-bg);
      background-image: linear-gradient(135deg, rgba(13, 17, 23, 0.92) 0%, rgba(24, 30, 37, 0.88) 100%), url('/assets/images/d54478dbe5468876.webp');
      background-size: cover;
      background-position: center;
      color: #FFFFFF;
      padding: 120px 0 100px;
      border-bottom: 1px solid var(--border-dark);
    }
    .hero-layout {
      display: grid;
      grid-template-columns: 1.2fr 0.8fr;
      gap: 48px;
      align-items: center;
    }
    .hero-content h1 {
      font-size: 3.25rem;
      font-weight: 800;
      line-height: 1.2;
      letter-spacing: -0.03em;
      margin-bottom: 24px;
    }
    .hero-content p {
      font-size: 1.125rem;
      color: #C9D5E8;
      margin-bottom: 36px;
      line-height: 1.8;
      max-width: 620px;
    }
    .hero-actions {
      display: flex;
      gap: 16px;
      margin-bottom: 48px;
    }
    .hero-specs-badge {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 16px;
      border-top: 1px solid rgba(255, 255, 255, 0.15);
      padding-top: 28px;
    }
    .spec-item .num {
      font-size: 1.75rem;
      font-weight: 700;
      color: var(--accent);
      font-variant-numeric: tabular-nums;
    }
    .spec-item .lbl {
      font-size: 0.85rem;
      color: #8E9DB2;
      margin-top: 4px;
    }
    .hero-card-preview {
      background: rgba(24, 30, 37, 0.85);
      border: 1px solid var(--border-dark);
      border-radius: var(--radius);
      padding: 24px;
      box-shadow: 0 16px 36px rgba(0, 0, 0, 0.3);
    }
    .hero-card-preview img {
      border-radius: var(--radius-sm);
      margin-bottom: 20px;
      aspect-ratio: 16/10;
      object-fit: cover;
    }
    .card-meta-line {
      display: flex;
      justify-content: space-between;
      border-bottom: 1px solid var(--border-dark);
      padding-bottom: 12px;
      margin-bottom: 12px;
      font-size: 0.875rem;
    }

    /* 2. 精密制造与品牌介绍 (#about) */
    .about-layout {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 64px;
      align-items: center;
    }
    .about-image-wrap {
      position: relative;
      border-radius: var(--radius);
      overflow: hidden;
      border: 1px solid var(--border-color);
      box-shadow: var(--shadow-sm);
    }
    .about-image-wrap img {
      width: 100%;
      height: 440px;
      object-fit: cover;
    }
    .about-params-table {
      margin-top: 28px;
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 16px;
    }
    .param-box {
      background: #FFFFFF;
      border: 1px solid var(--border-color);
      padding: 16px;
      border-radius: var(--radius-sm);
    }
    .param-box .p-title {
      font-size: 0.875rem;
      color: var(--text-muted);
      margin-bottom: 6px;
    }
    .param-box .p-val {
      font-size: 1.125rem;
      font-weight: 700;
      color: var(--text-main);
    }

    /* 3. 核心优势 (#advantages) */
    .grid-3x2 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .advantage-card {
      background: var(--bg-card);
      border: 1px solid var(--border-color);
      border-radius: var(--radius);
      padding: 32px 24px;
      transition: var(--transition);
    }
    .advantage-card:hover {
      border-color: var(--primary);
      box-shadow: var(--shadow-hover);
      transform: translateY(-4px);
    }
    .card-icon-tag {
      display: inline-block;
      padding: 6px 12px;
      background: var(--primary-light);
      color: var(--primary);
      border-radius: var(--radius-sm);
      font-size: 0.8125rem;
      font-weight: 600;
      margin-bottom: 20px;
    }
    .advantage-card h3 {
      font-size: 1.25rem;
      font-weight: 700;
      margin-bottom: 12px;
      color: var(--text-main);
    }
    .advantage-card p {
      font-size: 0.9375rem;
      color: var(--text-secondary);
      line-height: 1.7;
    }

    /* 4. 热门零部件选型 (#products) */
    .products-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 28px;
    }
    .product-card {
      background: #FFFFFF;
      border: 1px solid var(--border-color);
      border-radius: var(--radius);
      overflow: hidden;
      display: flex;
      flex-direction: column;
      transition: var(--transition);
    }
    .product-card:hover {
      border-color: var(--primary);
      box-shadow: var(--shadow-hover);
    }
    .product-img-box {
      width: 100%;
      height: 240px;
      background: #EDF2F7;
      position: relative;
    }
    .product-img-box img {
      width: 100%;
      height: 100%;
      object-fit: cover;
    }
    .product-body {
      padding: 24px;
      flex: 1;
      display: flex;
      flex-direction: column;
    }
    .product-tag {
      font-size: 0.8125rem;
      color: var(--primary);
      font-weight: 600;
      margin-bottom: 8px;
    }
    .product-body h3 {
      font-size: 1.25rem;
      font-weight: 700;
      margin-bottom: 12px;
    }
    .product-body p {
      font-size: 0.9375rem;
      color: var(--text-secondary);
      line-height: 1.65;
      margin-bottom: 20px;
    }
    .product-specs-list {
      margin-top: auto;
      border-top: 1px solid var(--border-color);
      padding-top: 16px;
      margin-bottom: 20px;
      font-size: 0.85rem;
      color: var(--text-secondary);
      display: grid;
      gap: 8px;
    }
    .spec-row {
      display: flex;
      justify-content: space-between;
    }
    .spec-row strong {
      color: var(--text-main);
    }

    /* 5. 深色车间理念 (#philosophy) */
    .philosophy-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 48px;
      align-items: center;
    }
    .tech-list {
      display: grid;
      gap: 20px;
      margin-top: 28px;
    }
    .tech-item {
      background: var(--dark-card);
      border: 1px solid var(--border-dark);
      padding: 20px;
      border-radius: var(--radius-sm);
    }
    .tech-item h4 {
      font-size: 1.1rem;
      color: #FFFFFF;
      margin-bottom: 8px;
      display: flex;
      align-items: center;
      gap: 10px;
    }
    .tech-item h4::before {
      content: "";
      display: inline-block;
      width: 6px;
      height: 16px;
      background: var(--accent);
      border-radius: 2px;
    }
    .tech-item p {
      font-size: 0.9rem;
      color: #9AA8BA;
      line-height: 1.6;
    }

    /* 6. 行业集成故事 (#cases) */
    .cases-stream {
      display: grid;
      gap: 48px;
    }
    .case-row {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 48px;
      align-items: center;
      background: #FFFFFF;
      border: 1px solid var(--border-color);
      border-radius: var(--radius);
      padding: 36px;
    }
    .case-row.reverse {
      grid-template-columns: 1fr 1fr;
    }
    .case-img-box {
      border-radius: var(--radius-sm);
      overflow: hidden;
      height: 320px;
    }
    .case-img-box img {
      width: 100%;
      height: 100%;
      object-fit: cover;
    }
    .case-content h3 {
      font-size: 1.5rem;
      font-weight: 700;
      margin-bottom: 12px;
    }
    .case-content p {
      font-size: 0.95rem;
      color: var(--text-secondary);
      line-height: 1.7;
      margin-bottom: 20px;
    }
    .case-results {
      background: var(--bg-page);
      border-left: 3px solid var(--primary);
      padding: 12px 16px;
      font-size: 0.875rem;
      color: var(--text-main);
    }

    /* 7. 数据统计条 (#metrics) */
    .metrics-section {
      background: var(--dark-bg);
      border-top: 1px solid var(--border-dark);
      border-bottom: 1px solid var(--border-dark);
      padding: 64px 0;
    }
    .metrics-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 32px;
      text-align: center;
    }
    .metric-item .val {
      font-size: 3rem;
      font-weight: 800;
      color: #FFFFFF;
      font-variant-numeric: tabular-nums;
      margin-bottom: 8px;
    }
    .metric-item .unit {
      font-size: 1.25rem;
      color: var(--accent);
      font-weight: 600;
    }
    .metric-item .label {
      font-size: 0.95rem;
      color: #8E9DB2;
      margin-top: 6px;
    }

    /* 8. 客户评价 (#testimonials) */
    .testimonials-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .testimonial-card {
      background: #FFFFFF;
      border: 1px solid var(--border-color);
      border-radius: var(--radius);
      padding: 32px 24px;
      display: flex;
      flex-direction: column;
      justify-content: space-between;
    }
    .rating-stars {
      color: #FF7D00;
      font-size: 1rem;
      margin-bottom: 16px;
      letter-spacing: 2px;
    }
    .testimonial-card p {
      font-size: 0.95rem;
      color: var(--text-secondary);
      line-height: 1.7;
      margin-bottom: 24px;
    }
    .client-info {
      border-top: 1px solid var(--border-color);
      padding-top: 16px;
    }
    .client-name {
      font-weight: 700;
      font-size: 0.95rem;
      color: var(--text-main);
    }
    .client-role {
      font-size: 0.8125rem;
      color: var(--text-muted);
    }

    /* 9. 动态与资讯 (#news) */
    .news-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .news-card {
      background: #FFFFFF;
      border: 1px solid var(--border-color);
      border-radius: var(--radius);
      padding: 24px;
      display: flex;
      flex-direction: column;
      transition: var(--transition);
    }
    .news-card:hover {
      border-color: var(--primary);
    }
    .news-meta {
      display: flex;
      justify-content: space-between;
      font-size: 0.8125rem;
      color: var(--text-muted);
      margin-bottom: 12px;
    }
    .news-card h3 {
      font-size: 1.15rem;
      font-weight: 700;
      line-height: 1.4;
      margin-bottom: 12px;
    }
    .news-card p {
      font-size: 0.9rem;
      color: var(--text-secondary);
      line-height: 1.65;
      margin-bottom: 20px;
    }
    .news-link {
      margin-top: auto;
      font-size: 0.875rem;
      font-weight: 600;
      color: var(--primary);
      display: inline-flex;
      align-items: center;
      gap: 4px;
    }

    /* 10. 常见问答 (#faq) */
    .faq-container {
      max-width: 900px;
      margin: 0 auto;
      display: grid;
      gap: 16px;
    }
    .faq-item {
      background: #FFFFFF;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-sm);
      overflow: hidden;
      transition: var(--transition);
    }
    .faq-item[open] {
      border-color: var(--primary);
      background-color: #FAFCFF;
    }
    .faq-summary {
      padding: 20px 24px;
      font-weight: 600;
      font-size: 1.05rem;
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
      user-select: none;
      list-style: none;
    }
    .faq-summary::-webkit-details-marker {
      display: none;
    }
    .faq-summary::after {
      content: "+";
      font-size: 1.5rem;
      line-height: 1;
      color: var(--primary);
      transition: transform 0.2s;
    }
    .faq-item[open] .faq-summary::after {
      content: "−";
    }
    .faq-body {
      padding: 0 24px 20px;
      font-size: 0.95rem;
      color: var(--text-secondary);
      line-height: 1.75;
      border-top: 1px solid #F0F2F5;
      margin-top: 8px;
      padding-top: 16px;
    }

    /* 11. 品质保障横带 (#guarantee) */
    .guarantee-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
    }
    .guarantee-card {
      background: #FFFFFF;
      border: 1px solid var(--border-color);
      border-radius: var(--radius);
      padding: 24px;
      text-align: center;
    }
    .guarantee-card .icon-box {
      width: 48px;
      height: 48px;
      background: var(--primary-light);
      color: var(--primary);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      margin: 0 auto 16px;
      font-weight: 700;
      font-size: 1.1rem;
    }
    .guarantee-card h4 {
      font-size: 1.05rem;
      margin-bottom: 8px;
    }
    .guarantee-card p {
      font-size: 0.85rem;
      color: var(--text-secondary);
      line-height: 1.6;
    }

    /* 12. 工程咨询转化区 (#contact) */
    .contact-card-box {
      background: #FFFFFF;
      border: 1px solid var(--border-color);
      border-radius: var(--radius);
      overflow: hidden;
      display: grid;
      grid-template-columns: 1fr 1.2fr;
      box-shadow: var(--shadow-sm);
    }
    .contact-sidebar {
      background: var(--dark-bg);
      color: #FFFFFF;
      padding: 48px 40px;
      display: flex;
      flex-direction: column;
      justify-content: space-between;
    }
    .contact-sidebar h3 {
      font-size: 1.75rem;
      margin-bottom: 16px;
    }
    .contact-sidebar p {
      color: #A4B2C6;
      font-size: 0.95rem;
      line-height: 1.7;
      margin-bottom: 32px;
    }
    .contact-meta-list {
      display: grid;
      gap: 16px;
      font-size: 0.9rem;
    }
    .contact-meta-item {
      display: flex;
      align-items: flex-start;
      gap: 12px;
    }
    .contact-form-wrap {
      padding: 48px 40px;
    }
    .form-group {
      margin-bottom: 20px;
    }
    .form-group label {
      display: block;
      font-size: 0.875rem;
      font-weight: 600;
      margin-bottom: 8px;
      color: var(--text-main);
    }
    .form-control {
      width: 100%;
      padding: 12px 16px;
      font-size: 0.95rem;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-sm);
      outline: none;
      transition: var(--transition);
      background-color: #FAFAFA;
      font-family: inherit;
    }
    .form-control:focus {
      background-color: #FFFFFF;
      border-color: var(--primary);
      box-shadow: 0 0 0 3px rgba(22, 93, 255, 0.12);
    }
    textarea.form-control {
      resize: vertical;
      min-height: 100px;
    }

    /* 页脚 */
    .site-footer {
      background: #0B0E13;
      color: #8E9DB2;
      border-top: 1px solid var(--border-dark);
      padding: 64px 0 32px;
      font-size: 0.875rem;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1.5fr;
      gap: 48px;
      margin-bottom: 48px;
    }
    .footer-col h4 {
      color: #FFFFFF;
      font-size: 1rem;
      margin-bottom: 20px;
    }
    .footer-links {
      list-style: none;
      display: grid;
      gap: 12px;
    }
    .footer-links a:hover {
      color: #FFFFFF;
    }
    .footer-bottom {
      border-top: 1px solid var(--border-dark);
      padding-top: 32px;
      display: flex;
      justify-content: space-between;
      align-items: center;
      flex-wrap: wrap;
      gap: 16px;
    }

    /* 响应式断点 */
    @media (max-width: 1024px) {
      .hero-layout, .about-layout, .philosophy-grid, .contact-card-box {
        grid-template-columns: 1fr;
      }
      .grid-3x2, .products-grid, .testimonials-grid, .news-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .metrics-grid, .guarantee-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .case-row {
        grid-template-columns: 1fr;
      }
      .case-row.reverse .case-img-box {
        order: -1;
      }
      .footer-grid {
        grid-template-columns: 1fr 1fr;
      }
    }

    @media (max-width: 768px) {
      .topbar {
        display: none;
      }
      .nav-links {
        display: none;
        position: absolute;
        top: 72px;
        left: 0;
        width: 100%;
        background: #FFFFFF;
        flex-direction: column;
        padding: 24px;
        box-shadow: 0 10px 20px rgba(0,0,0,0.1);
        border-bottom: 1px solid var(--border-color);
      }
      .nav-links.active {
        display: flex;
      }
      .mobile-toggle {
        display: block;
      }
      .nav-cta {
        display: none;
      }
      .section-title {
        font-size: 1.75rem;
      }
      .hero-content h1 {
        font-size: 2.25rem;
      }
      .grid-3x2, .products-grid, .testimonials-grid, .news-grid, .metrics-grid, .guarantee-grid {
        grid-template-columns: 1fr;
      }
      .hero-specs-badge {
        grid-template-columns: 1fr;
      }
      .footer-grid {
        grid-template-columns: 1fr;
      }
      .about-params-table {
        grid-template-columns: 1fr;
      }
      .section-spacing {
        padding: 64px 0;
      }
    }