/* roulang page: index */
/* CSS 设计变量系统：精密汽车工业美学 */
    :root {
      --primary-dark: #111827;      /* 精密机械炭黑灰 */
      --secondary-dark: #1f2937;    /* 工业深灰 */
      --deep-navy: #0b0f17;          /* 严苛实验区深冷灰黑 */
      --brand-blue: #0284c7;         /* 机械工业钴蓝 */
      --brand-cyan: #0ea5e9;         /* 电镀青钛色 */
      --accent-orange: #ea580c;      /* 严苛指标冷橙色 */
      --bg-light: #f8fafc;           /* 冷调超浅灰主底色 */
      --bg-white: #ffffff;
      --text-main: #0f172a;          /* 标题高饱和碳素色 */
      --text-muted: #475569;         /* 规范正文冷灰 */
      --text-sub: #64748b;           /* 说明性弱文字 */
      --border-color: #e2e8f0;       /* 细微工业描边 */
      --border-dark: #334155;        /* 深色区边框 */
      --radius-sm: 4px;
      --radius-md: 8px;
      --radius-lg: 12px;
      --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
      --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.08), 0 2px 4px -2px rgba(0, 0, 0, 0.05);
      --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -4px rgba(0, 0, 0, 0.05);
      --transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
    }

    /* 基础 Reset 与规范 */
    *, *::before, *::after {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }

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

    body {
      font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
      background-color: var(--bg-light);
      color: var(--text-muted);
      line-height: 1.7;
      letter-spacing: -0.01em;
      overflow-x: hidden;
      -webkit-font-smoothing: antialiased;
    }

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

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

    button, input, select, textarea {
      font-family: inherit;
      font-size: inherit;
      border: none;
      outline: none;
    }

    /* 布局容器 */
    .container {
      width: 100%;
      max-width: 1280px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 24px;
      padding-right: 24px;
    }

    .section-wrap {
      padding-top: 88px;
      padding-bottom: 88px;
      position: relative;
    }

    .section-alt {
      background-color: #ffffff;
      border-top: 1px solid var(--border-color);
      border-bottom: 1px solid var(--border-color);
    }

    /* 板块通用头部 */
    .section-header {
      margin-bottom: 48px;
      max-width: 760px;
    }

    .section-tag {
      display: inline-flex;
      align-items: center;
      gap: 6px;
      font-size: 13px;
      font-weight: 700;
      text-transform: uppercase;
      letter-spacing: 0.05em;
      color: var(--brand-blue);
      background-color: #e0f2fe;
      padding: 4px 12px;
      border-radius: var(--radius-sm);
      margin-bottom: 12px;
    }

    .section-title {
      font-size: 32px;
      font-weight: 800;
      color: var(--text-main);
      line-height: 1.28;
      letter-spacing: -0.02em;
      margin-bottom: 16px;
    }

    .section-intro {
      font-size: 16px;
      color: var(--text-sub);
      line-height: 1.75;
    }

    /* 工业按钮视觉体系 */
    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      font-weight: 600;
      font-size: 15px;
      padding: 12px 26px;
      border-radius: var(--radius-md);
      cursor: pointer;
      transition: var(--transition);
      min-height: 46px;
      white-space: nowrap;
    }

    .btn-primary {
      background-color: var(--brand-blue);
      color: #ffffff;
      box-shadow: 0 4px 12px rgba(2, 132, 199, 0.25);
    }

    .btn-primary:hover {
      background-color: #0369a1;
      transform: translateY(-2px);
      box-shadow: 0 6px 16px rgba(2, 132, 199, 0.35);
      color: #ffffff;
    }

    .btn-secondary {
      background-color: var(--secondary-dark);
      color: #ffffff;
    }

    .btn-secondary:hover {
      background-color: var(--primary-dark);
      transform: translateY(-2px);
      color: #ffffff;
    }

    .btn-outline {
      border: 1px solid var(--border-color);
      background-color: #ffffff;
      color: var(--secondary-dark);
    }

    .btn-outline:hover {
      background-color: var(--bg-light);
      border-color: #cbd5e1;
      color: var(--brand-blue);
    }

    /* 顶部双行导航 */
    .site-header {
      position: sticky;
      top: 0;
      z-index: 999;
      width: 100%;
    }

    .top-meta-bar {
      background-color: var(--primary-dark);
      color: #94a3b8;
      font-size: 13px;
      padding: 7px 0;
      border-bottom: 1px solid #1e293b;
    }

    .top-meta-bar .container {
      display: flex;
      justify-content: space-between;
      align-items: center;
    }

    .top-meta-items {
      display: flex;
      align-items: center;
      gap: 20px;
    }

    .top-meta-items span {
      display: inline-flex;
      align-items: center;
      gap: 6px;
    }

    .main-nav-bar {
      backdrop-filter: blur(12px);
      background-color: rgba(255, 255, 255, 0.94);
      border-bottom: 1px solid var(--border-color);
      transition: var(--transition);
    }

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

    .nav-brand {
      display: flex;
      align-items: center;
      gap: 10px;
      font-size: 22px;
      font-weight: 800;
      letter-spacing: -0.02em;
      color: var(--primary-dark);
    }

    .brand-icon {
      width: 38px;
      height: 38px;
      background: linear-gradient(135deg, var(--brand-blue), #0369a1);
      color: #ffffff;
      display: flex;
      align-items: center;
      justify-content: center;
      border-radius: var(--radius-md);
      font-size: 18px;
    }

    .nav-links {
      display: flex;
      align-items: center;
      gap: 28px;
      list-style: none;
    }

    .nav-links a {
      font-size: 15px;
      font-weight: 600;
      color: var(--secondary-dark);
      position: relative;
      padding: 6px 0;
    }

    .nav-links a:hover {
      color: var(--brand-blue);
    }

    .nav-action {
      display: flex;
      align-items: center;
      gap: 16px;
    }

    .menu-toggle {
      display: none;
      background: none;
      font-size: 22px;
      color: var(--primary-dark);
      cursor: pointer;
    }

    /* 1. 首屏 Banner (#hero) - 双栏门户：左主张右快捷入口网格 */
    .hero-section {
      background-color: #0f172a;
      background-image: linear-gradient(rgba(15, 23, 42, 0.88), rgba(15, 23, 42, 0.94)), url('/assets/images/cb0de989ddb6b3e2.webp');
      background-size: cover;
      background-position: center;
      color: #ffffff;
      padding: 96px 0 100px;
      position: relative;
    }

    .hero-grid {
      display: grid;
      grid-template-columns: 1.15fr 0.85fr;
      gap: 48px;
      align-items: center;
    }

    .hero-badge {
      display: inline-flex;
      align-items: center;
      gap: 8px;
      background-color: rgba(14, 165, 233, 0.15);
      border: 1px solid rgba(14, 165, 233, 0.35);
      color: #38bdf8;
      padding: 5px 14px;
      border-radius: var(--radius-sm);
      font-size: 13px;
      font-weight: 700;
      margin-bottom: 20px;
    }

    .hero-title {
      font-size: 42px;
      font-weight: 800;
      line-height: 1.24;
      letter-spacing: -0.02em;
      margin-bottom: 22px;
      color: #f8fafc;
    }

    .hero-title span {
      color: #38bdf8;
    }

    .hero-desc {
      font-size: 16px;
      line-height: 1.8;
      color: #cbd5e1;
      margin-bottom: 32px;
    }

    .hero-cta-group {
      display: flex;
      flex-wrap: wrap;
      gap: 16px;
      margin-bottom: 36px;
    }

    .hero-trust-row {
      display: flex;
      align-items: center;
      gap: 24px;
      padding-top: 24px;
      border-top: 1px solid rgba(255, 255, 255, 0.12);
      font-size: 13px;
      color: #94a3b8;
    }

    .trust-indicator {
      display: flex;
      align-items: center;
      gap: 8px;
    }

    .trust-indicator i {
      color: #38bdf8;
    }

    /* 首屏右侧：快捷技术与图纸资料检索入口网格 */
    .hero-quick-portal {
      background-color: rgba(30, 41, 59, 0.8);
      border: 1px solid rgba(255, 255, 255, 0.15);
      border-radius: var(--radius-lg);
      padding: 28px;
      backdrop-filter: blur(8px);
      box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.3);
    }

    .portal-header {
      border-bottom: 1px solid rgba(255, 255, 255, 0.1);
      padding-bottom: 16px;
      margin-bottom: 20px;
    }

    .portal-header h3 {
      font-size: 18px;
      font-weight: 700;
      color: #ffffff;
      display: flex;
      align-items: center;
      gap: 8px;
    }

    .portal-header p {
      font-size: 13px;
      color: #94a3b8;
      margin-top: 4px;
    }

    .portal-grid {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 14px;
    }

    .portal-card {
      background-color: rgba(15, 23, 42, 0.6);
      border: 1px solid rgba(255, 255, 255, 0.08);
      border-radius: var(--radius-md);
      padding: 16px;
      display: block;
      transition: var(--transition);
    }

    .portal-card:hover {
      border-color: var(--brand-cyan);
      background-color: rgba(2, 132, 199, 0.18);
      transform: translateY(-2px);
    }

    .portal-card-icon {
      font-size: 20px;
      color: var(--brand-cyan);
      margin-bottom: 8px;
    }

    .portal-card-name {
      font-size: 14px;
      font-weight: 700;
      color: #f1f5f9;
      margin-bottom: 4px;
    }

    .portal-card-hint {
      font-size: 12px;
      color: #94a3b8;
      line-height: 1.4;
    }

    /* 2. 资料目录与汽车零部件智造介绍 (#about) */
    .about-split {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 56px;
      align-items: center;
    }

    .about-content h2 {
      font-size: 32px;
      font-weight: 800;
      color: var(--text-main);
      margin-bottom: 20px;
      line-height: 1.3;
    }

    .about-lead {
      font-size: 16px;
      color: var(--text-muted);
      line-height: 1.8;
      margin-bottom: 28px;
    }

    .cert-badges {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 16px;
      margin-bottom: 32px;
    }

    .cert-badge-item {
      display: flex;
      align-items: flex-start;
      gap: 12px;
      background-color: #f1f5f9;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      padding: 14px 16px;
    }

    .cert-badge-item i {
      font-size: 22px;
      color: var(--brand-blue);
      margin-top: 2px;
    }

    .cert-badge-item strong {
      display: block;
      font-size: 14px;
      color: var(--primary-dark);
      font-weight: 700;
    }

    .cert-badge-item span {
      font-size: 12px;
      color: var(--text-sub);
    }

    .about-media-box {
      position: relative;
    }

    .about-img-main {
      border-radius: var(--radius-lg);
      box-shadow: var(--shadow-lg);
      border: 1px solid var(--border-color);
      width: 100%;
      height: 380px;
      object-fit: cover;
    }

    .about-float-stat {
      position: absolute;
      bottom: -24px;
      left: 24px;
      background-color: var(--primary-dark);
      color: #ffffff;
      padding: 20px 28px;
      border-radius: var(--radius-md);
      box-shadow: var(--shadow-lg);
      border: 1px solid rgba(255, 255, 255, 0.1);
    }

    .float-stat-num {
      font-size: 28px;
      font-weight: 800;
      color: #38bdf8;
      line-height: 1;
      margin-bottom: 4px;
    }

    .float-stat-label {
      font-size: 13px;
      color: #cbd5e1;
    }

    /* 3. 汽车零部件核心卖点三连与优势矩阵 (#advantages) */
    .adv-grid-6 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 28px;
    }

    .adv-card {
      background-color: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-lg);
      padding: 32px 26px;
      transition: var(--transition);
      box-shadow: var(--shadow-sm);
    }

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

    .adv-icon {
      width: 52px;
      height: 52px;
      background-color: #e0f2fe;
      color: var(--brand-blue);
      display: flex;
      align-items: center;
      justify-content: center;
      border-radius: var(--radius-md);
      font-size: 22px;
      margin-bottom: 20px;
    }

    .adv-title {
      font-size: 18px;
      font-weight: 700;
      color: var(--text-main);
      margin-bottom: 12px;
    }

    .adv-text {
      font-size: 14px;
      color: var(--text-muted);
      line-height: 1.7;
    }

    /* 4. 热门汽车零部件产品系统展示 (#products) */
    .products-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 28px;
    }

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

    .product-card:hover {
      box-shadow: var(--shadow-md);
      transform: translateY(-3px);
    }

    .product-thumb-wrap {
      position: relative;
      height: 220px;
      overflow: hidden;
      background-color: #e2e8f0;
    }

    .product-thumb {
      width: 100%;
      height: 100%;
      object-fit: cover;
      transition: transform 0.4s ease;
    }

    .product-card:hover .product-thumb {
      transform: scale(1.05);
    }

    .product-tag {
      position: absolute;
      top: 14px;
      right: 14px;
      background-color: rgba(15, 23, 42, 0.85);
      color: #38bdf8;
      font-size: 12px;
      font-weight: 600;
      padding: 4px 10px;
      border-radius: var(--radius-sm);
      backdrop-filter: blur(4px);
    }

    .product-body {
      padding: 24px;
      display: flex;
      flex-direction: column;
      flex: 1;
    }

    .product-name {
      font-size: 19px;
      font-weight: 700;
      color: var(--text-main);
      margin-bottom: 10px;
    }

    .product-summary {
      font-size: 14px;
      color: var(--text-sub);
      line-height: 1.6;
      margin-bottom: 20px;
    }

    .spec-table-mini {
      background-color: #f8fafc;
      border-radius: var(--radius-md);
      padding: 12px;
      margin-bottom: 20px;
      font-size: 13px;
    }

    .spec-row {
      display: flex;
      justify-content: space-between;
      padding: 4px 0;
      border-bottom: 1px dashed #e2e8f0;
    }

    .spec-row:last-child {
      border-bottom: none;
    }

    .spec-k {
      color: var(--text-sub);
    }

    .spec-v {
      color: var(--primary-dark);
      font-weight: 600;
    }

    .product-card-footer {
      margin-top: auto;
      display: flex;
      justify-content: space-between;
      align-items: center;
      padding-top: 14px;
      border-top: 1px solid #f1f5f9;
    }

    /* 5. 深色对比：汽车工程理念与严苛实验案例 (#philosophy) */
    .philosophy-section {
      background-color: var(--deep-navy);
      color: #f8fafc;
      border-top: 1px solid #1e293b;
      border-bottom: 1px solid #1e293b;
    }

    .philosophy-layout {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 56px;
      align-items: center;
    }

    .philosophy-info .section-tag {
      background-color: rgba(234, 88, 12, 0.2);
      color: #fb923c;
    }

    .philosophy-info h2 {
      font-size: 32px;
      font-weight: 800;
      color: #ffffff;
      margin-bottom: 20px;
      line-height: 1.3;
    }

    .philosophy-info p {
      font-size: 15px;
      color: #94a3b8;
      line-height: 1.8;
      margin-bottom: 28px;
    }

    .test-matrix-list {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 16px;
    }

    .test-box {
      background-color: #111827;
      border: 1px solid #1f2937;
      border-radius: var(--radius-md);
      padding: 18px;
    }

    .test-value {
      font-size: 24px;
      font-weight: 800;
      color: #fb923c;
      margin-bottom: 4px;
    }

    .test-label {
      font-size: 14px;
      font-weight: 700;
      color: #f1f5f9;
      margin-bottom: 6px;
    }

    .test-desc {
      font-size: 12px;
      color: #64748b;
      line-height: 1.5;
    }

    .philosophy-media {
      position: relative;
    }

    .philosophy-img {
      border-radius: var(--radius-lg);
      border: 1px solid #334155;
      width: 100%;
      height: 400px;
      object-fit: cover;
    }

    /* 6. 全场景装配与车型适配演示区 (#scenarios) */
    .scenario-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 28px;
    }

    .scenario-card {
      background-color: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-lg);
      padding: 28px;
      box-shadow: var(--shadow-sm);
    }

    .scenario-badge {
      display: inline-block;
      font-size: 12px;
      font-weight: 700;
      padding: 3px 10px;
      border-radius: var(--radius-sm);
      background-color: #f1f5f9;
      color: var(--secondary-dark);
      margin-bottom: 16px;
    }

    .scenario-title {
      font-size: 19px;
      font-weight: 700;
      color: var(--text-main);
      margin-bottom: 12px;
    }

    .scenario-desc {
      font-size: 14px;
      color: var(--text-muted);
      line-height: 1.7;
      margin-bottom: 20px;
    }

    .scenario-checklist {
      list-style: none;
      font-size: 13px;
      color: var(--text-muted);
    }

    .scenario-checklist li {
      display: flex;
      align-items: center;
      gap: 8px;
      margin-bottom: 8px;
    }

    .scenario-checklist i {
      color: #10b981;
      font-size: 12px;
    }

    /* 7. 主机厂与后市场用户案例 (#cases) */
    .case-grid {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 32px;
    }

    .case-card {
      background-color: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-lg);
      padding: 32px;
      box-shadow: var(--shadow-sm);
      display: flex;
      flex-direction: column;
      transition: var(--transition);
    }

    .case-card:hover {
      box-shadow: var(--shadow-md);
      border-color: #cbd5e1;
    }

    .case-meta {
      display: flex;
      justify-content: space-between;
      align-items: center;
      margin-bottom: 16px;
    }

    .case-cat {
      font-size: 13px;
      font-weight: 700;
      color: var(--brand-blue);
      background-color: #e0f2fe;
      padding: 4px 10px;
      border-radius: var(--radius-sm);
    }

    .case-date {
      font-size: 13px;
      color: var(--text-sub);
    }

    .case-title {
      font-size: 20px;
      font-weight: 700;
      color: var(--text-main);
      margin-bottom: 14px;
      line-height: 1.4;
    }

    .case-summary {
      font-size: 14px;
      color: var(--text-muted);
      line-height: 1.75;
      margin-bottom: 24px;
    }

    .case-metric-box {
      background-color: #f8fafc;
      border: 1px solid #f1f5f9;
      border-radius: var(--radius-md);
      padding: 16px;
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 12px;
      text-align: center;
    }

    .case-metric-item strong {
      display: block;
      font-size: 18px;
      font-weight: 800;
      color: var(--primary-dark);
    }

    .case-metric-item span {
      font-size: 12px;
      color: var(--text-sub);
    }

    /* 8. 关键工业产能与质检数据统计条 (#stats) */
    .stats-bar-section {
      background: linear-gradient(135deg, var(--primary-dark), #1e293b);
      color: #ffffff;
      padding: 60px 0;
    }

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

    .stat-item-block {
      position: relative;
    }

    .stat-item-block:not(:last-child)::after {
      content: "";
      position: absolute;
      right: -16px;
      top: 15%;
      height: 70%;
      width: 1px;
      background-color: rgba(255, 255, 255, 0.15);
    }

    .stat-huge-num {
      font-size: 40px;
      font-weight: 800;
      color: #38bdf8;
      line-height: 1.1;
      margin-bottom: 8px;
      font-family: inherit;
    }

    .stat-title-cn {
      font-size: 15px;
      font-weight: 700;
      color: #f8fafc;
      margin-bottom: 4px;
    }

    .stat-sub-note {
      font-size: 12px;
      color: #94a3b8;
    }

    /* 9. 汽车主机厂客户真实评价与背书 (#reviews) */
    .reviews-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 28px;
    }

    .review-card {
      background-color: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-lg);
      padding: 28px;
      box-shadow: var(--shadow-sm);
      display: flex;
      flex-direction: column;
      justify-content: space-between;
    }

    .review-stars {
      color: #f59e0b;
      margin-bottom: 16px;
      font-size: 14px;
    }

    .review-text {
      font-size: 14px;
      color: var(--text-muted);
      line-height: 1.8;
      margin-bottom: 24px;
      font-style: normal;
    }

    .reviewer-info {
      display: flex;
      align-items: center;
      gap: 14px;
      border-top: 1px solid #f1f5f9;
      padding-top: 16px;
    }

    .reviewer-avatar-placeholder {
      width: 44px;
      height: 44px;
      background-color: #e2e8f0;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      color: var(--secondary-dark);
      font-weight: 700;
      font-size: 14px;
    }

    .reviewer-detail strong {
      display: block;
      font-size: 14px;
      color: var(--text-main);
    }

    .reviewer-detail span {
      font-size: 12px;
      color: var(--text-sub);
    }

    /* 10. 行业技术动态与零部件资讯证据 (#news) */
    .news-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 28px;
    }

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

    .news-card:hover {
      transform: translateY(-3px);
      box-shadow: var(--shadow-md);
    }

    .news-thumb-box {
      height: 180px;
      background-color: #e2e8f0;
      overflow: hidden;
    }

    .news-thumb-img {
      width: 100%;
      height: 100%;
      object-fit: cover;
      transition: transform 0.3s ease;
    }

    .news-card:hover .news-thumb-img {
      transform: scale(1.05);
    }

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

    .news-date-tag {
      font-size: 12px;
      color: var(--text-sub);
      margin-bottom: 8px;
    }

    .news-title {
      font-size: 17px;
      font-weight: 700;
      color: var(--text-main);
      line-height: 1.45;
      margin-bottom: 12px;
    }

    .news-excerpt {
      font-size: 13px;
      color: var(--text-muted);
      line-height: 1.7;
      margin-bottom: 18px;
    }

    .news-read-link {
      margin-top: auto;
      font-size: 13px;
      font-weight: 600;
      color: var(--brand-blue);
      display: inline-flex;
      align-items: center;
      gap: 6px;
    }

    /* 11. 异议拆解与汽车零部件采购 FAQ 手风琴 (#faq) */
    .faq-container-narrow {
      max-width: 860px;
      margin: 0 auto;
    }

    .faq-accordion {
      display: flex;
      flex-direction: column;
      gap: 16px;
    }

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

    .faq-item.active {
      border-color: var(--brand-cyan);
      box-shadow: var(--shadow-sm);
    }

    .faq-question {
      padding: 20px 24px;
      font-size: 16px;
      font-weight: 700;
      color: var(--text-main);
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
      user-select: none;
      background-color: #ffffff;
      transition: background-color 0.2s ease;
    }

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

    .faq-item.active .faq-question {
      background-color: #f0f9ff;
      color: var(--brand-blue);
    }

    .faq-icon-arrow {
      font-size: 14px;
      color: var(--text-sub);
      transition: transform 0.3s ease;
    }

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

    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease-out;
      background-color: #ffffff;
    }

    .faq-answer-inner {
      padding: 0 24px 20px;
      font-size: 14px;
      color: var(--text-muted);
      line-height: 1.8;
      border-top: 1px solid #f1f5f9;
      padding-top: 16px;
    }

    /* 12. 汽车零部件品质保障与服务承诺条 (#guarantee) */
    .guarantee-bar {
      background-color: var(--primary-dark);
      color: #ffffff;
      border-top: 1px solid #1e293b;
      border-bottom: 1px solid #1e293b;
      padding: 48px 0;
    }

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

    .guarantee-box {
      display: flex;
      align-items: flex-start;
      gap: 16px;
    }

    .guarantee-icon {
      font-size: 28px;
      color: var(--brand-cyan);
      flex-shrink: 0;
      margin-top: 2px;
    }

    .guarantee-box strong {
      display: block;
      font-size: 16px;
      font-weight: 700;
      color: #ffffff;
      margin-bottom: 4px;
    }

    .guarantee-box p {
      font-size: 13px;
      color: #94a3b8;
      line-height: 1.5;
    }

    /* 13. 高转化咨询与工程图纸索取表单区 (#inquiry) */
    .inquiry-wrapper {
      background-color: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-lg);
      box-shadow: var(--shadow-lg);
      overflow: hidden;
      display: grid;
      grid-template-columns: 1fr 1.25fr;
    }

    .inquiry-left-panel {
      background-color: #0f172a;
      color: #ffffff;
      padding: 48px 40px;
      display: flex;
      flex-direction: column;
      justify-content: space-between;
    }

    .inquiry-left-panel h3 {
      font-size: 26px;
      font-weight: 800;
      margin-bottom: 16px;
      line-height: 1.3;
    }

    .inquiry-left-panel p {
      font-size: 14px;
      color: #94a3b8;
      line-height: 1.75;
      margin-bottom: 32px;
    }

    .inquiry-contact-list {
      list-style: none;
      display: flex;
      flex-direction: column;
      gap: 20px;
    }

    .contact-item-row {
      display: flex;
      align-items: center;
      gap: 14px;
    }

    .contact-item-icon {
      width: 40px;
      height: 40px;
      background-color: rgba(255, 255, 255, 0.08);
      border-radius: var(--radius-md);
      display: flex;
      align-items: center;
      justify-content: center;
      color: var(--brand-cyan);
      font-size: 16px;
    }

    .contact-item-text span {
      display: block;
      font-size: 12px;
      color: #94a3b8;
    }

    .contact-item-text strong {
      font-size: 15px;
      color: #ffffff;
    }

    .inquiry-form-panel {
      padding: 48px 40px;
      background-color: #ffffff;
    }

    .form-grid-2 {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 20px;
      margin-bottom: 20px;
    }

    .form-group {
      display: flex;
      flex-direction: column;
      gap: 6px;
      margin-bottom: 20px;
    }

    .form-group label {
      font-size: 13px;
      font-weight: 700;
      color: var(--text-main);
    }

    .form-group input,
    .form-group select,
    .form-group textarea {
      width: 100%;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      padding: 10px 14px;
      font-size: 14px;
      color: var(--text-main);
      background-color: #f8fafc;
      transition: var(--transition);
    }

    .form-group input:focus,
    .form-group select:focus,
    .form-group textarea:focus {
      background-color: #ffffff;
      border-color: var(--brand-blue);
      box-shadow: 0 0 0 3px rgba(2, 132, 199, 0.15);
    }

    .file-upload-mock {
      border: 2px dashed #cbd5e1;
      border-radius: var(--radius-md);
      padding: 16px;
      text-align: center;
      background-color: #f8fafc;
      cursor: pointer;
      transition: var(--transition);
    }

    .file-upload-mock:hover {
      border-color: var(--brand-blue);
      background-color: #f0f9ff;
    }

    .file-upload-mock i {
      font-size: 24px;
      color: var(--brand-blue);
      margin-bottom: 6px;
    }

    .file-upload-mock p {
      font-size: 13px;
      color: var(--text-sub);
    }

    /* 移动端底部常驻转化条 */
    .mobile-float-cta {
      display: none;
      position: fixed;
      bottom: 0;
      left: 0;
      right: 0;
      background-color: rgba(15, 23, 42, 0.95);
      backdrop-filter: blur(10px);
      padding: 10px 16px;
      border-top: 1px solid rgba(255, 255, 255, 0.1);
      z-index: 998;
    }

    .mobile-float-inner {
      display: flex;
      gap: 12px;
    }

    .mobile-float-inner a {
      flex: 1;
      font-size: 14px;
      font-weight: 700;
      padding: 10px 0;
      text-align: center;
      border-radius: var(--radius-md);
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 6px;
    }

    /* 页脚 Footer 规范 */
    .site-footer {
      background-color: #030712;
      color: #94a3b8;
      padding: 80px 0 32px;
      border-top: 1px solid #1e293b;
      font-size: 14px;
    }

    .footer-top-grid {
      display: grid;
      grid-template-columns: 1.5fr 1fr 1fr 1.2fr;
      gap: 48px;
      margin-bottom: 56px;
    }

    .footer-brand-title {
      font-size: 22px;
      font-weight: 800;
      color: #f8fafc;
      margin-bottom: 16px;
      display: flex;
      align-items: center;
      gap: 10px;
    }

    .footer-brand-p {
      line-height: 1.8;
      color: #64748b;
      margin-bottom: 20px;
    }

    .footer-col h4 {
      font-size: 16px;
      font-weight: 700;
      color: #f1f5f9;
      margin-bottom: 20px;
      position: relative;
      padding-bottom: 8px;
    }

    .footer-col h4::after {
      content: "";
      position: absolute;
      bottom: 0;
      left: 0;
      width: 28px;
      height: 2px;
      background-color: var(--brand-blue);
    }

    .footer-links-list {
      list-style: none;
      display: flex;
      flex-direction: column;
      gap: 12px;
    }

    .footer-links-list a:hover {
      color: var(--brand-cyan);
      padding-left: 4px;
    }

    .footer-bottom-bar {
      border-top: 1px solid #111827;
      padding-top: 28px;
      display: flex;
      justify-content: space-between;
      align-items: center;
      flex-wrap: wrap;
      gap: 16px;
      font-size: 13px;
      color: #64748b;
    }

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

    /* 响应式断点适配 */
    @media (max-width: 1024px) {
      .hero-grid,
      .about-split,
      .philosophy-layout,
      .inquiry-wrapper {
        grid-template-columns: 1fr;
        gap: 40px;
      }
      .adv-grid-6,
      .products-grid,
      .scenario-grid,
      .news-grid,
      .reviews-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .footer-top-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .stats-grid-4 {
        grid-template-columns: repeat(2, 1fr);
      }
      .stat-item-block:nth-child(2)::after {
        display: none;
      }
      .guarantee-grid {
        grid-template-columns: repeat(2, 1fr);
      }
    }

    @media (max-width: 768px) {
      .top-meta-bar {
        display: none;
      }
      .section-wrap {
        padding-top: 60px;
        padding-bottom: 60px;
      }
      .section-title {
        font-size: 26px;
      }
      .hero-title {
        font-size: 28px;
      }
      .adv-grid-6,
      .products-grid,
      .scenario-grid,
      .case-grid,
      .news-grid,
      .reviews-grid,
      .form-grid-2,
      .footer-top-grid,
      .stats-grid-4,
      .guarantee-grid {
        grid-template-columns: 1fr;
      }
      .stat-item-block::after {
        display: none !important;
      }
      .menu-toggle {
        display: block;
      }
      .nav-links {
        display: none;
        position: absolute;
        top: 72px;
        left: 0;
        right: 0;
        background-color: #ffffff;
        flex-direction: column;
        padding: 20px 24px;
        border-bottom: 1px solid var(--border-color);
        box-shadow: var(--shadow-lg);
        gap: 16px;
      }
      .nav-links.open {
        display: flex;
      }
      .nav-action .btn {
        display: none;
      }
      .mobile-float-cta {
        display: block;
      }
      body {
        padding-bottom: 60px;
      }
      .inquiry-left-panel,
      .inquiry-form-panel {
        padding: 32px 20px;
      }
    }