/* roulang page: index */
:root {
      --primary: #0F2C59;
      --primary-dark: #0A192F;
      --accent: #FF5722;
      --accent-hover: #E64A19;
      --bg-light: #F8FAFC;
      --bg-white: #FFFFFF;
      --text-main: #1E293B;
      --text-sub: #64748B;
      --border-color: #E2E8F0;
      --card-shadow: 0 4px 20px -2px rgba(15, 44, 89, 0.07);
      --radius: 6px;
      --transition: all 0.3s ease;
    }
    * { box-sizing: border-box; margin: 0; padding: 0; }
    html { scroll-behavior: smooth; }
    body {
      font-family: system-ui, -apple-system, "PingFang SC", "Microsoft YaHei", sans-serif;
      color: var(--text-main);
      background-color: var(--bg-white);
      line-height: 1.75;
      font-size: 16px;
      overflow-x: hidden;
    }
    a { text-decoration: none; color: inherit; transition: var(--transition); }
    img { max-width: 100%; height: auto; display: block; }
    button, input, select, textarea { font-family: inherit; font-size: inherit; }
    .container {
      width: 100%;
      max-width: 1240px;
      margin: 0 auto;
      padding: 0 20px;
    }
    .top-bar {
      background-color: var(--primary-dark);
      color: #94A3B8;
      font-size: 13px;
      padding: 8px 0;
      border-bottom: 1px solid rgba(255, 255, 255, 0.08);
    }
    .top-bar-inner {
      display: flex;
      justify-content: space-between;
      align-items: center;
      flex-wrap: wrap;
      gap: 10px;
    }
    .top-info { display: flex; gap: 20px; }
    .top-info span { display: inline-flex; align-items: center; gap: 6px; }
    header.site-header {
      position: sticky;
      top: 0;
      background: rgba(255, 255, 255, 0.98);
      backdrop-filter: blur(8px);
      z-index: 1000;
      box-shadow: 0 2px 12px rgba(0,0,0,0.04);
      border-bottom: 1px solid var(--border-color);
    }
    .nav-inner {
      display: flex;
      justify-content: space-between;
      align-items: center;
      height: 74px;
    }
    .logo-area {
      display: flex;
      align-items: center;
      gap: 12px;
      font-weight: 800;
      font-size: 22px;
      color: var(--primary);
      letter-spacing: -0.5px;
    }
    .logo-badge {
      background: var(--accent);
      color: #fff;
      font-size: 11px;
      font-weight: 700;
      padding: 2px 6px;
      border-radius: 4px;
      text-transform: uppercase;
    }
    .nav-links {
      display: flex;
      align-items: center;
      gap: 26px;
      list-style: none;
    }
    .nav-links a {
      font-weight: 500;
      font-size: 15px;
      color: var(--text-main);
      position: relative;
      padding: 6px 0;
    }
    .nav-links a:hover, .nav-links a.active {
      color: var(--accent);
    }
    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--accent);
      transition: var(--transition);
    }
    .nav-links a:hover::after, .nav-links a.active::after {
      width: 100%;
    }
    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 10px 22px;
      font-weight: 600;
      border-radius: var(--radius);
      cursor: pointer;
      border: 1px solid transparent;
      transition: var(--transition);
      min-height: 44px;
      white-space: nowrap;
    }
    .btn-accent {
      background-color: var(--accent);
      color: #FFFFFF;
    }
    .btn-accent:hover {
      background-color: var(--accent-hover);
      box-shadow: 0 4px 14px rgba(255, 87, 34, 0.35);
    }
    .btn-outline {
      border-color: var(--primary);
      color: var(--primary);
      background: transparent;
    }
    .btn-outline:hover {
      background-color: var(--primary);
      color: #fff;
    }
    .btn-white {
      background: #fff;
      color: var(--primary);
    }
    .btn-white:hover {
      background: #f1f5f9;
    }
    .section-wrap {
      padding: 90px 0;
      position: relative;
    }
    .bg-light { background-color: var(--bg-light); }
    .bg-dark { background-color: var(--primary-dark); color: #fff; }
    .bg-white { background-color: var(--bg-white); }
    .section-header {
      max-width: 820px;
      margin: 0 auto 54px;
      text-align: center;
    }
    .section-tag {
      display: inline-block;
      font-size: 12px;
      font-weight: 700;
      letter-spacing: 1px;
      color: var(--accent);
      background: rgba(255, 87, 34, 0.08);
      padding: 4px 12px;
      border-radius: 50px;
      margin-bottom: 14px;
      text-transform: uppercase;
    }
    .bg-dark .section-tag {
      background: rgba(255, 255, 255, 0.1);
      color: #FF7043;
    }
    .section-title {
      font-size: 32px;
      font-weight: 800;
      color: var(--primary);
      line-height: 1.35;
      margin-bottom: 18px;
    }
    .bg-dark .section-title { color: #fff; }
    .section-desc {
      font-size: 16px;
      color: var(--text-sub);
      line-height: 1.8;
    }
    .bg-dark .section-desc { color: #94A3B8; }
    .hero-banner {
      position: relative;
      background: linear-gradient(rgba(10, 25, 47, 0.88), rgba(15, 44, 89, 0.92)), url('/assets/images/09a7345be2c05807.jpg') center/cover no-repeat;
      color: #fff;
      padding: 120px 0 100px;
      min-height: 600px;
      display: flex;
      align-items: center;
    }
    .hero-content {
      max-width: 880px;
      margin: 0 auto;
      text-align: center;
    }
    .hero-pill {
      display: inline-flex;
      align-items: center;
      gap: 8px;
      background: rgba(255, 255, 255, 0.12);
      border: 1px solid rgba(255, 255, 255, 0.2);
      padding: 6px 16px;
      border-radius: 30px;
      font-size: 14px;
      margin-bottom: 24px;
    }
    .hero-pill span.point {
      width: 8px;
      height: 8px;
      background: var(--accent);
      border-radius: 50%;
      box-shadow: 0 0 8px var(--accent);
    }
    .hero-content h1 {
      font-size: 46px;
      font-weight: 800;
      line-height: 1.25;
      margin-bottom: 22px;
      letter-spacing: -0.5px;
    }
    .hero-content p {
      font-size: 18px;
      line-height: 1.8;
      color: #CBD5E1;
      margin-bottom: 36px;
      max-width: 780px;
      margin-left: auto;
      margin-right: auto;
    }
    .hero-actions {
      display: flex;
      justify-content: center;
      gap: 18px;
      flex-wrap: wrap;
    }
    .grid-3 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 28px;
    }
    .grid-2 {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 36px;
      align-items: center;
    }
    .grid-4 {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
    }
    .challenge-card {
      background: #fff;
      border: 1px solid var(--border-color);
      border-top: 4px solid #EF4444;
      border-radius: var(--radius);
      padding: 32px 26px;
      box-shadow: var(--card-shadow);
      transition: var(--transition);
    }
    .challenge-card:hover {
      transform: translateY(-4px);
      box-shadow: 0 12px 30px -4px rgba(15, 44, 89, 0.12);
    }
    .challenge-card h3 {
      font-size: 19px;
      color: var(--primary);
      margin-bottom: 14px;
    }
    .challenge-card p {
      font-size: 15px;
      color: var(--text-sub);
      line-height: 1.7;
    }
    .about-split {
      display: grid;
      grid-template-columns: 4.5fr 5.5fr;
      gap: 48px;
      align-items: center;
    }
    .about-img-box {
      position: relative;
      border-radius: var(--radius);
      overflow: hidden;
      box-shadow: var(--card-shadow);
    }
    .about-img-box img {
      width: 100%;
      height: 430px;
      object-fit: cover;
    }
    .about-text h2 {
      font-size: 32px;
      font-weight: 800;
      color: var(--primary);
      line-height: 1.3;
      margin-bottom: 20px;
    }
    .about-text p {
      color: var(--text-sub);
      font-size: 15px;
      margin-bottom: 16px;
      line-height: 1.8;
    }
    .spec-badges {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 16px;
      margin-top: 28px;
    }
    .spec-item {
      background: var(--bg-light);
      border: 1px solid var(--border-color);
      padding: 14px 18px;
      border-radius: var(--radius);
    }
    .spec-item strong {
      display: block;
      color: var(--primary);
      font-size: 16px;
      margin-bottom: 4px;
    }
    .spec-item span {
      font-size: 13px;
      color: var(--text-sub);
    }
    .feature-card {
      background: #fff;
      border: 1px solid var(--border-color);
      padding: 30px 24px;
      border-radius: var(--radius);
      box-shadow: var(--card-shadow);
      transition: var(--transition);
      position: relative;
    }
    .feature-card:hover {
      transform: translateY(-4px);
      border-color: var(--primary);
    }
    .feature-card .feat-idx {
      font-size: 26px;
      font-weight: 800;
      color: rgba(15, 44, 89, 0.12);
      position: absolute;
      top: 20px;
      right: 20px;
    }
    .feature-card h3 {
      font-size: 19px;
      color: var(--primary);
      margin-bottom: 12px;
    }
    .feature-card p {
      font-size: 14px;
      color: var(--text-sub);
      line-height: 1.7;
    }
    .solution-card {
      background: #fff;
      border-radius: var(--radius);
      overflow: hidden;
      border: 1px solid var(--border-color);
      box-shadow: var(--card-shadow);
      display: flex;
      flex-direction: column;
      transition: var(--transition);
    }
    .solution-card:hover {
      transform: translateY(-4px);
      box-shadow: 0 12px 30px rgba(15, 44, 89, 0.12);
    }
    .solution-card img {
      width: 100%;
      height: 210px;
      object-fit: cover;
    }
    .solution-body {
      padding: 26px;
      flex: 1;
      display: flex;
      flex-direction: column;
    }
    .solution-tag {
      display: inline-block;
      align-self: flex-start;
      background: #EFF6FF;
      color: var(--primary);
      font-size: 12px;
      font-weight: 600;
      padding: 4px 10px;
      border-radius: 4px;
      margin-bottom: 12px;
    }
    .solution-body h3 {
      font-size: 20px;
      color: var(--primary);
      margin-bottom: 12px;
    }
    .solution-body p {
      font-size: 14px;
      color: var(--text-sub);
      line-height: 1.7;
      margin-bottom: 20px;
      flex: 1;
    }
    .solution-list {
      list-style: none;
      margin-bottom: 22px;
      border-top: 1px dashed var(--border-color);
      padding-top: 14px;
    }
    .solution-list li {
      font-size: 13px;
      color: var(--text-main);
      margin-bottom: 8px;
      display: flex;
      align-items: center;
      gap: 6px;
    }
    .solution-list li::before {
      content: '✓';
      color: var(--accent);
      font-weight: bold;
    }
    .timeline-steps {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
      position: relative;
    }
    .step-box {
      background: #fff;
      border: 1px solid var(--border-color);
      padding: 28px 22px;
      border-radius: var(--radius);
      box-shadow: var(--card-shadow);
      position: relative;
    }
    .step-num {
      width: 40px;
      height: 40px;
      background: var(--primary);
      color: #fff;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 800;
      border-radius: 50%;
      margin-bottom: 18px;
    }
    .step-box h3 {
      font-size: 18px;
      color: var(--primary);
      margin-bottom: 10px;
    }
    .step-box p {
      font-size: 14px;
      color: var(--text-sub);
      line-height: 1.7;
    }
    .hardware-section {
      background: linear-gradient(135deg, #0A192F 0%, #0F2C59 100%);
      color: #fff;
    }
    .hardware-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 40px;
      align-items: center;
    }
    .hardware-list {
      list-style: none;
      display: flex;
      flex-direction: column;
      gap: 18px;
    }
    .hardware-item {
      background: rgba(255, 255, 255, 0.05);
      border: 1px solid rgba(255, 255, 255, 0.1);
      padding: 20px 24px;
      border-radius: var(--radius);
    }
    .hardware-item h4 {
      font-size: 17px;
      color: #fff;
      margin-bottom: 6px;
    }
    .hardware-item p {
      font-size: 14px;
      color: #94A3B8;
      line-height: 1.6;
    }
    .story-card {
      background: #fff;
      border: 1fr solid var(--border-color);
      border-radius: var(--radius);
      overflow: hidden;
      box-shadow: var(--card-shadow);
      display: grid;
      grid-template-columns: 1fr 1.2fr;
    }
    .story-card img {
      width: 100%;
      height: 100%;
      object-fit: cover;
    }
    .story-content {
      padding: 34px 28px;
      display: flex;
      flex-direction: column;
      justify-content: center;
    }
    .story-content h3 {
      font-size: 21px;
      color: var(--primary);
      margin-bottom: 12px;
    }
    .story-content p {
      font-size: 14px;
      color: var(--text-sub);
      line-height: 1.8;
      margin-bottom: 16px;
    }
    .story-meta {
      display: flex;
      gap: 18px;
      font-size: 13px;
      color: var(--accent);
      font-weight: 600;
    }
    .stats-card {
      background: #fff;
      border: 1px solid var(--border-color);
      padding: 32px 20px;
      border-radius: var(--radius);
      text-align: center;
      box-shadow: var(--card-shadow);
    }
    .stat-number {
      font-size: 42px;
      font-weight: 800;
      color: var(--accent);
      margin-bottom: 6px;
      letter-spacing: -1px;
    }
    .stat-label {
      font-size: 14px;
      color: var(--primary);
      font-weight: 700;
      margin-bottom: 4px;
    }
    .stat-sub {
      font-size: 12px;
      color: var(--text-sub);
    }
    .testimonial-card {
      background: #fff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius);
      padding: 30px 24px;
      box-shadow: var(--card-shadow);
      position: relative;
    }
    .testimonial-badge {
      display: inline-block;
      font-size: 12px;
      background: #FEF3C7;
      color: #92400E;
      padding: 2px 8px;
      border-radius: 4px;
      margin-bottom: 16px;
      font-weight: 600;
    }
    .testimonial-card p {
      font-size: 14px;
      color: var(--text-main);
      line-height: 1.8;
      margin-bottom: 20px;
      font-style: italic;
    }
    .author-box {
      display: flex;
      align-items: center;
      gap: 12px;
      border-top: 1px solid var(--border-color);
      padding-top: 16px;
    }
    .author-info h4 {
      font-size: 15px;
      color: var(--primary);
    }
    .author-info span {
      font-size: 12px;
      color: var(--text-sub);
    }
    .news-card {
      background: #fff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius);
      overflow: hidden;
      box-shadow: var(--card-shadow);
      transition: var(--transition);
      display: flex;
      flex-direction: column;
    }
    .news-card:hover {
      transform: translateY(-4px);
    }
    .news-card img {
      width: 100%;
      height: 190px;
      object-fit: cover;
    }
    .news-info {
      padding: 22px;
      flex: 1;
      display: flex;
      flex-direction: column;
    }
    .news-date {
      font-size: 12px;
      color: var(--text-sub);
      margin-bottom: 8px;
    }
    .news-info h3 {
      font-size: 17px;
      color: var(--primary);
      margin-bottom: 10px;
      line-height: 1.45;
    }
    .news-info p {
      font-size: 13px;
      color: var(--text-sub);
      line-height: 1.7;
      flex: 1;
    }
    .faq-list {
      max-width: 860px;
      margin: 0 auto;
      display: flex;
      flex-direction: column;
      gap: 16px;
    }
    .faq-item {
      background: #fff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius);
      overflow: hidden;
      box-shadow: var(--card-shadow);
    }
    .faq-question {
      padding: 20px 24px;
      font-weight: 700;
      font-size: 16px;
      color: var(--primary);
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
      user-select: none;
      background: #fff;
    }
    .faq-question:hover {
      background: #F8FAFC;
    }
    .faq-toggle-icon {
      font-size: 18px;
      color: var(--accent);
      transition: var(--transition);
    }
    .faq-answer {
      padding: 0 24px 20px;
      font-size: 14px;
      color: var(--text-sub);
      line-height: 1.8;
      display: block;
      border-top: 1px solid #F1F5F9;
      margin-top: 4px;
      padding-top: 14px;
    }
    .contact-container {
      background: #fff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius);
      box-shadow: 0 10px 35px rgba(15, 44, 89, 0.08);
      overflow: hidden;
      display: grid;
      grid-template-columns: 5fr 5fr;
    }
    .contact-left {
      background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
      color: #fff;
      padding: 50px 40px;
      display: flex;
      flex-direction: column;
      justify-content: center;
    }
    .contact-left h3 {
      font-size: 26px;
      margin-bottom: 16px;
    }
    .contact-left p {
      font-size: 15px;
      color: #CBD5E1;
      line-height: 1.8;
      margin-bottom: 24px;
    }
    .contact-points {
      list-style: none;
      display: flex;
      flex-direction: column;
      gap: 14px;
    }
    .contact-points li {
      font-size: 14px;
      display: flex;
      align-items: center;
      gap: 10px;
      color: #E2E8F0;
    }
    .contact-right {
      padding: 50px 40px;
      background: #fff;
    }
    .form-group {
      margin-bottom: 20px;
    }
    .form-group label {
      display: block;
      font-size: 13px;
      font-weight: 600;
      color: var(--primary);
      margin-bottom: 6px;
    }
    .form-control {
      width: 100%;
      padding: 11px 14px;
      border: 1px solid var(--border-color);
      border-radius: 4px;
      font-size: 14px;
      color: var(--text-main);
      outline: none;
      transition: var(--transition);
    }
    .form-control:focus {
      border-color: var(--accent);
      box-shadow: 0 0 0 3px rgba(255, 87, 34, 0.12);
    }
    footer.site-footer {
      background-color: var(--primary-dark);
      color: #94A3B8;
      padding: 70px 0 30px;
      font-size: 14px;
      border-top: 1px solid rgba(255, 255, 255, 0.08);
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1.5fr;
      gap: 40px;
      margin-bottom: 50px;
    }
    .footer-col h4 {
      color: #fff;
      font-size: 16px;
      margin-bottom: 20px;
      font-weight: 700;
    }
    .footer-col p {
      line-height: 1.8;
      font-size: 13px;
      margin-bottom: 16px;
    }
    .footer-links {
      list-style: none;
      display: flex;
      flex-direction: column;
      gap: 10px;
    }
    .footer-links a {
      color: #94A3B8;
      font-size: 13px;
    }
    .footer-links a:hover {
      color: var(--accent);
      padding-left: 4px;
    }
    .footer-bottom {
      border-top: 1px solid rgba(255, 255, 255, 0.08);
      padding-top: 28px;
      display: flex;
      justify-content: space-between;
      align-items: center;
      flex-wrap: wrap;
      gap: 14px;
      font-size: 13px;
    }
    .mobile-menu-btn {
      display: none;
      background: none;
      border: none;
      cursor: pointer;
      padding: 8px;
      color: var(--primary);
      font-size: 24px;
    }
    @media (max-width: 1024px) {
      .grid-3 { grid-template-columns: repeat(2, 1fr); }
      .grid-4 { grid-template-columns: repeat(2, 1fr); }
      .timeline-steps { grid-template-columns: repeat(2, 1fr); }
      .about-split { grid-template-columns: 1fr; }
      .hardware-grid { grid-template-columns: 1fr; }
      .story-card { grid-template-columns: 1fr; }
      .footer-grid { grid-template-columns: 1fr 1fr; }
    }
    @media (max-width: 768px) {
      .nav-links {
        display: none;
        position: absolute;
        top: 74px;
        left: 0;
        width: 100%;
        background: #fff;
        flex-direction: column;
        padding: 24px;
        box-shadow: 0 10px 20px rgba(0,0,0,0.1);
        gap: 16px;
        align-items: flex-start;
      }
      .nav-links.active { display: flex; }
      .mobile-menu-btn { display: block; }
      .hero-content h1 { font-size: 30px; }
      .hero-content p { font-size: 15px; }
      .grid-3 { grid-template-columns: 1fr; }
      .grid-4 { grid-template-columns: 1fr; }
      .timeline-steps { grid-template-columns: 1fr; }
      .contact-container { grid-template-columns: 1fr; }
      .footer-grid { grid-template-columns: 1fr; }
      .section-wrap { padding: 60px 0; }
    }