/* roulang page: index */
:root {
      --primary: #1A5F7A;
      --primary-dark: #154E61;
      --accent: #E8B85C;
      --bg-light: #F7F9FC;
      --bg-white: #FFFFFF;
      --bg-section: #EDF1F5;
      --text-primary: #1E293B;
      --text-secondary: #475569;
      --text-muted: #94A3B8;
      --border: #E2E8F0;
      --radius-sm: 8px;
      --radius-md: 12px;
      --radius-lg: 16px;
      --shadow-card: 0 1px 3px rgba(0,0,0,0.04), 0 1px 2px rgba(0,0,0,0.06);
      --shadow-hover: 0 10px 25px rgba(0,0,0,0.08), 0 4px 10px rgba(0,0,0,0.04);
      --transition: 0.25s ease;
      --container: 1280px;
      --spacing-xs: 8px;
      --spacing-sm: 16px;
      --spacing-md: 24px;
      --spacing-lg: 32px;
      --spacing-xl: 48px;
      --spacing-2xl: 64px;
      --spacing-3xl: 96px;
    }

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

    body {
      font-family: 'Inter', 'Noto Sans SC', system-ui, -apple-system, sans-serif;
      background-color: var(--bg-light);
      color: var(--text-primary);
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
    }

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

    a {
      text-decoration: none;
      color: inherit;
    }

    button {
      font-family: inherit;
      cursor: pointer;
    }

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

    /* 导航 */
    .navbar {
      background: var(--bg-white);
      border-bottom: 1px solid var(--border);
      position: sticky;
      top: 0;
      z-index: 50;
      transition: box-shadow var(--transition);
    }

    .navbar.scrolled {
      box-shadow: 0 2px 10px rgba(0,0,0,0.04);
    }

    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      max-width: var(--container);
      margin: 0 auto;
      padding: 0 var(--spacing-md);
      height: 72px;
    }

    .logo {
      display: flex;
      align-items: center;
      gap: 6px;
      font-size: 22px;
      font-weight: 700;
      color: var(--primary);
      letter-spacing: -0.3px;
      white-space: nowrap;
    }

    .logo i {
      color: var(--accent);
      font-size: 18px;
      margin-right: 4px;
    }

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

    .nav-links a {
      font-size: 16px;
      font-weight: 500;
      color: var(--text-secondary);
      position: relative;
      padding: 4px 0;
      transition: color var(--transition);
    }

    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 50%;
      transform: translateX(-50%) scaleX(0);
      width: 100%;
      height: 2px;
      background: var(--primary);
      transition: transform 0.2s ease;
    }

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

    .nav-links a:hover::after {
      transform: translateX(-50%) scaleX(1);
    }

    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      background: none;
      border: none;
      padding: 8px;
    }

    .hamburger span {
      display: block;
      width: 24px;
      height: 2px;
      background: var(--primary);
      border-radius: 2px;
      transition: 0.3s;
    }

    @media (max-width: 767px) {
      .nav-links {
        display: none;
        position: absolute;
        top: 72px;
        left: 0;
        width: 100%;
        background: white;
        flex-direction: column;
        align-items: flex-start;
        padding: 24px;
        gap: 20px;
        box-shadow: var(--shadow-hover);
        border-bottom: 1px solid var(--border);
      }
      .nav-links.active {
        display: flex;
      }
      .hamburger {
        display: flex;
      }
      .nav-container {
        justify-content: space-between;
      }
    }

    /* Hero */
    .hero {
      background: linear-gradient(135deg, #F7F9FC 0%, #FFFFFF 100%);
      padding: 80px 0;
    }

    .hero-grid {
      display: flex;
      align-items: center;
      gap: 48px;
    }

    .hero-text {
      flex: 1;
    }

    .hero-text h1 {
      font-size: 32px;
      line-height: 40px;
      font-weight: 700;
      letter-spacing: -0.5px;
      color: var(--text-primary);
      margin-bottom: 24px;
    }

    .hero-sub {
      font-size: 18px;
      color: var(--text-secondary);
      max-width: 45ch;
      margin-bottom: 32px;
    }

    .btn-group {
      display: flex;
      flex-wrap: wrap;
      gap: 16px;
    }

    .btn-primary {
      background: var(--primary);
      color: white;
      font-weight: 600;
      padding: 14px 28px;
      border-radius: var(--radius-sm);
      border: none;
      transition: all var(--transition);
      box-shadow: 0 2px 6px rgba(26,95,122,0.2);
    }

    .btn-primary:hover {
      background: var(--primary-dark);
      transform: translateY(-2px);
      box-shadow: 0 8px 18px rgba(26,95,122,0.25);
    }

    .btn-outline {
      background: transparent;
      border: 1px solid var(--primary);
      color: var(--primary);
      font-weight: 600;
      padding: 14px 28px;
      border-radius: var(--radius-sm);
      transition: all var(--transition);
    }

    .btn-outline:hover {
      background: rgba(26,95,122,0.08);
      transform: translateY(-2px);
    }

    .hero-image {
      flex: 1;
      border-radius: var(--radius-lg);
      overflow: hidden;
      background: #EFF3F6;
    }

    .hero-image img {
      width: 100%;
      height: auto;
      object-fit: cover;
      border-radius: var(--radius-lg);
    }

    @media (max-width: 767px) {
      .hero-grid {
        flex-direction: column-reverse;
        gap: 32px;
      }
      .hero-text h1 {
        font-size: 28px;
        line-height: 36px;
      }
      .btn-group {
        flex-direction: column;
        align-items: flex-start;
      }
    }

    /* 通用板块 */
    section {
      padding: 100px 0;
    }

    @media (max-width: 1023px) {
      section {
        padding: 60px 0;
      }
    }

    .section-title {
      font-size: 28px;
      line-height: 36px;
      font-weight: 600;
      color: var(--text-primary);
      margin-bottom: 16px;
      text-align: center;
    }

    .section-sub {
      color: var(--text-secondary);
      text-align: center;
      max-width: 600px;
      margin: 0 auto 48px;
      font-size: 16px;
    }

    /* 优势不对称网格 */
    .advantages-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 24px;
      max-width: 1000px;
      margin: 0 auto;
    }

    .adv-item {
      background: var(--bg-white);
      padding: 32px;
      border-radius: var(--radius-md);
      border-bottom: 3px solid var(--primary);
      transition: all var(--transition);
    }

    .adv-item.wide {
      grid-column: span 2;
    }

    .adv-icon {
      width: 48px;
      height: 48px;
      background: rgba(26,95,122,0.08);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      margin-bottom: 20px;
      color: var(--accent);
      font-size: 24px;
    }

    .adv-item h3 {
      font-size: 20px;
      font-weight: 600;
      margin-bottom: 12px;
    }

    .adv-item p {
      color: var(--text-secondary);
    }

    @media (max-width: 767px) {
      .advantages-grid {
        grid-template-columns: 1fr;
      }
      .adv-item.wide {
        grid-column: span 1;
      }
    }

    /* 产品瀑布流 */
    .products-grid {
      display: grid;
      grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
      gap: 24px;
    }

    .product-card {
      background: var(--bg-white);
      border-radius: var(--radius-md);
      box-shadow: var(--shadow-card);
      transition: var(--transition);
      display: flex;
      flex-direction: column;
    }

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

    .product-card img {
      width: 100%;
      height: 200px;
      object-fit: cover;
      border-radius: var(--radius-md) var(--radius-md) 0 0;
    }

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

    .product-body h3 {
      font-size: 20px;
      font-weight: 600;
      margin-bottom: 8px;
    }

    .product-body p {
      color: var(--text-secondary);
      margin-bottom: 16px;
      flex: 1;
    }

    .btn-link {
      color: var(--primary);
      font-weight: 600;
      display: inline-flex;
      align-items: center;
      gap: 4px;
      transition: gap 0.2s;
    }

    .btn-link:hover {
      gap: 8px;
    }

    /* 流程 */
    .process-steps {
      display: flex;
      justify-content: space-between;
      align-items: flex-start;
      gap: 24px;
      flex-wrap: wrap;
      position: relative;
    }

    .step {
      flex: 1;
      min-width: 140px;
      text-align: center;
      position: relative;
    }

    .step-circle {
      width: 56px;
      height: 56px;
      background: var(--primary);
      color: white;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 24px;
      font-weight: 700;
      margin: 0 auto 16px;
    }

    .step h4 {
      font-weight: 600;
      margin-bottom: 8px;
    }

    .step p {
      color: var(--text-secondary);
      font-size: 14px;
    }

    .process-steps::before {
      content: '';
      position: absolute;
      top: 28px;
      left: 10%;
      width: 80%;
      height: 1px;
      border-top: 2px dashed var(--border);
      z-index: 0;
    }

    .step {
      z-index: 1;
      background: var(--bg-section);
      padding: 24px 12px;
      border-radius: var(--radius-md);
    }

    @media (max-width: 767px) {
      .process-steps {
        flex-direction: column;
        align-items: center;
      }
      .process-steps::before {
        display: none;
      }
    }

    /* 案例 */
    .cases-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 24px;
    }

    .case-card {
      background: #F8FAFC;
      border-radius: var(--radius-md);
      overflow: hidden;
      border: 1px solid var(--border);
      transition: border 0.2s;
    }

    .case-card:hover {
      border-color: var(--primary);
    }

    .case-card img {
      width: 100%;
      aspect-ratio: 16/9;
      object-fit: cover;
    }

    .case-content {
      padding: 24px;
    }

    .case-number {
      font-size: 36px;
      font-weight: 700;
      color: var(--accent);
      line-height: 1.2;
    }

    @media (max-width: 767px) {
      .cases-grid {
        grid-template-columns: 1fr;
      }
    }

    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }

    .faq-item {
      border-bottom: 1px solid var(--border);
    }

    .faq-question {
      width: 100%;
      background: none;
      border: none;
      padding: 20px 0;
      font-size: 18px;
      font-weight: 600;
      color: var(--primary);
      display: flex;
      justify-content: space-between;
      align-items: center;
      text-align: left;
    }

    .faq-icon {
      font-size: 24px;
      transition: transform 0.3s;
    }

    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease, padding 0.3s;
      background: #F7F9FC;
      border-radius: 6px;
    }

    .faq-answer p {
      padding: 0 20px;
    }

    .faq-item.active .faq-answer {
      max-height: 200px;
      padding: 20px 0;
    }

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

    /* CTA */
    .cta-block {
      background: #EFF6F9;
      padding: 80px 0;
      text-align: center;
    }

    .cta-block h2 {
      font-size: 28px;
      font-weight: 600;
      margin-bottom: 16px;
    }

    /* 页脚 */
    .footer {
      background: #1E293B;
      color: #CBD5E1;
      padding: 64px 0 32px;
    }

    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 32px;
    }

    .footer-logo {
      font-size: 22px;
      font-weight: 700;
      color: white;
      margin-bottom: 16px;
    }

    .footer a {
      color: #CBD5E1;
      transition: color 0.2s;
    }

    .footer a:hover {
      color: white;
    }

    .copyright {
      border-top: 1px solid #334155;
      margin-top: 48px;
      padding-top: 24px;
      text-align: center;
      font-size: 14px;
    }

    @media (max-width: 767px) {
      .footer-grid {
        grid-template-columns: 1fr 1fr;
      }
    }