/* roulang page: index */
:root {
      --primary-blue: #0A66B2;
      --primary-green: #00A86B;
      --accent-orange: #E37222;
      --bg-light: #F5F7FA;
      --bg-white: #FFFFFF;
      --bg-dark: #1A1D23;
      --gray-border: #E2E6EB;
      --gray-light-bg: #E9ECEF;
      --text-primary: #1E293B;
      --text-secondary: #5A6B7F;
      --text-muted: #9BA5B3;
      --shadow-sm: 0 2px 12px rgba(0,0,0,0.04);
      --shadow-md: 0 8px 24px rgba(10,102,178,0.12);
      --border-radius-sm: 6px;
      --border-radius-md: 8px;
      --transition-base: 0.25s ease;
      --font-heading: 'Inter', 'SF Pro Display', 'PingFang SC', 'Microsoft YaHei', sans-serif;
      --font-body: 'Inter', 'SF Pro Text', 'PingFang SC', 'Microsoft YaHei', sans-serif;
      --nav-width: 280px;
    }
    * {
      box-sizing: border-box;
    }
    body {
      font-family: var(--font-body);
      background-color: var(--bg-light);
      color: var(--text-primary);
      line-height: 1.7;
      margin: 0;
      overflow-x: hidden;
    }
    h1, h2, h3, h4, .nav-logo-text, .step-number, .data-value {
      font-family: var(--font-heading);
      font-weight: 600;
    }
    a {
      text-decoration: none;
      transition: var(--transition-base);
      color: var(--primary-blue);
    }
    a:hover {
      color: #084E8C;
    }
    img {
      max-width: 100%;
      display: block;
    }
    .btn {
      border-radius: var(--border-radius-sm);
      padding: 0.7rem 1.8rem;
      font-weight: 500;
      transition: all var(--transition-base);
      border: none;
    }
    .btn-primary-custom {
      background-color: var(--primary-blue);
      color: #FFFFFF;
      border: 1px solid var(--primary-blue);
    }
    .btn-primary-custom:hover, .btn-primary-custom:focus {
      background-color: #084E8C;
      border-color: #084E8C;
      color: #FFFFFF;
      box-shadow: 0 4px 10px rgba(10,102,178,0.3);
    }
    .btn-outline-custom {
      background: transparent;
      color: var(--primary-blue);
      border: 1px solid var(--primary-blue);
    }
    .btn-outline-custom:hover {
      background-color: rgba(10,102,178,0.05);
      border-color: #084E8C;
      color: #084E8C;
    }
    .btn-accent {
      background-color: var(--accent-orange);
      color: #FFFFFF;
      border: 1px solid var(--accent-orange);
    }
    .btn-accent:hover {
      background-color: #c85d1a;
      border-color: #c85d1a;
      color: #FFFFFF;
    }
    .btn-outline-white {
      background: transparent;
      border: 1px solid rgba(255,255,255,0.8);
      color: #FFFFFF;
    }
    .btn-outline-white:hover {
      background: rgba(255,255,255,0.15);
      border-color: #FFFFFF;
      color: #FFFFFF;
    }
    /* 分屏布局 */
    .app-container {
      display: flex;
      min-height: 100vh;
      position: relative;
    }
    .side-nav {
      width: var(--nav-width);
      background-color: var(--bg-white);
      border-right: 1px solid rgba(0,0,0,0.05);
      box-shadow: 1px 0 8px rgba(0,0,0,0.02);
      display: flex;
      flex-direction: column;
      justify-content: space-between;
      position: fixed;
      left: 0;
      top: 0;
      bottom: 0;
      z-index: 1030;
      padding: 2rem 1.5rem;
      transition: transform 0.3s ease;
    }
    .nav-brand {
      margin-bottom: 2.5rem;
    }
    .nav-logo-text {
      font-size: 1.8rem;
      font-weight: 700;
      color: var(--primary-blue);
      letter-spacing: -0.3px;
      line-height: 1.2;
    }
    .nav-domain {
      font-size: 0.75rem;
      color: var(--text-muted);
      letter-spacing: 0.3px;
      margin-top: 0.2rem;
    }
    .nav-menu {
      list-style: none;
      padding: 0;
      margin: 0;
      flex: 1;
    }
    .nav-item {
      margin-bottom: 0.3rem;
    }
    .nav-link {
      display: flex;
      align-items: center;
      padding: 0.6rem 0.8rem;
      font-size: 0.9rem;
      font-weight: 500;
      color: var(--text-secondary);
      border-radius: 6px;
      transition: all 0.2s;
      border-left: 3px solid transparent;
    }
    .nav-link i {
      width: 22px;
      margin-right: 10px;
      font-size: 1rem;
    }
    .nav-link:hover, .nav-link.active {
      color: var(--primary-blue);
      background-color: rgba(10,102,178,0.04);
      border-left-color: var(--primary-blue);
    }
    .nav-contact-info {
      margin-top: auto;
      font-size: 0.8rem;
      color: var(--text-muted);
      border-top: 1px solid var(--gray-border);
      padding-top: 1.5rem;
    }
    .nav-contact-info i {
      margin-right: 6px;
      color: var(--primary-blue);
    }
    .main-content {
      margin-left: var(--nav-width);
      width: calc(100% - var(--nav-width));
      background-color: var(--bg-light);
    }
    .hero-section {
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      min-height: 100vh;
      position: relative;
      display: flex;
      align-items: center;
      padding: 3rem;
    }
    .hero-overlay {
      position: absolute;
      top: 0; left: 0; width: 100%; height: 100%;
      background: linear-gradient(135deg, rgba(10,102,178,0.85) 0%, rgba(0,168,107,0.7) 100%);
    }
    .hero-content {
      position: relative;
      z-index: 2;
      max-width: 650px;
      color: white;
    }
    .hero-content h1 {
      font-size: 2.8rem;
      font-weight: 700;
      letter-spacing: -0.5px;
      margin-bottom: 1.5rem;
      line-height: 1.3;
    }
    .hero-content p {
      font-size: 1.1rem;
      color: rgba(255,255,255,0.9);
      margin-bottom: 2rem;
    }
    .section-padding {
      padding: 100px 0;
    }
    .section-title {
      font-size: 2rem;
      font-weight: 600;
      margin-bottom: 0.75rem;
      color: var(--text-primary);
    }
    .section-subtitle {
      color: var(--text-secondary);
      font-size: 1rem;
      margin-bottom: 3rem;
    }
    .advantage-icon {
      width: 64px;
      height: 64px;
      background-color: #E8F2FB;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      color: var(--primary-blue);
      font-size: 1.8rem;
      margin-bottom: 1.5rem;
    }
    .card-custom {
      background: var(--bg-white);
      border: 1px solid var(--gray-border);
      border-radius: var(--border-radius-md);
      box-shadow: var(--shadow-sm);
      transition: all var(--transition-base);
    }
    .card-custom:hover {
      box-shadow: var(--shadow-md);
      transform: translateY(-2px);
    }
    .product-card-img {
      height: 200px;
      background-size: cover;
      background-position: center;
      position: relative;
      border-radius: 8px 8px 0 0;
    }
    .product-card-img::after {
      content: '';
      position: absolute;
      top: 0; left: 0; width: 100%; height: 100%;
      background: rgba(10,102,178,0.1);
      opacity: 0;
      transition: opacity 0.3s;
    }
    .card-custom:hover .product-card-img::after {
      opacity: 1;
    }
    .dark-bg {
      background-color: var(--bg-dark);
      color: #FFFFFF;
    }
    .data-value {
      font-size: 2.8rem;
      font-weight: 700;
      color: var(--primary-green);
    }
    .case-card {
      background: var(--bg-white);
      border-radius: var(--border-radius-md);
      overflow: hidden;
      display: flex;
      flex-direction: column;
    }
    .case-bg {
      height: 200px;
      background-size: cover;
      background-position: center;
    }
    .tag {
      background: #E8F2FB;
      color: var(--primary-blue);
      padding: 0.2rem 0.8rem;
      border-radius: 20px;
      font-size: 0.75rem;
      font-weight: 600;
    }
    .process-step {
      text-align: center;
      position: relative;
    }
    .step-circle {
      width: 48px;
      height: 48px;
      background: var(--primary-blue);
      color: #fff;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 700;
      font-size: 1.3rem;
      margin: 0 auto 1rem;
    }
    .accordion-custom .accordion-item {
      border: 1px solid var(--gray-border);
      border-radius: 8px;
      margin-bottom: 12px;
    }
    .accordion-custom .accordion-button {
      background: #fff;
      font-weight: 600;
      color: var(--text-primary);
      box-shadow: none;
    }
    .accordion-custom .accordion-button:not(.collapsed) {
      color: var(--primary-blue);
      background: #F8FAFB;
    }
    .form-control {
      border: 1px solid #D1D8E0;
      border-radius: 6px;
      padding: 0.6rem 1rem;
      font-size: 0.95rem;
    }
    .form-control:focus {
      border-color: var(--primary-blue);
      box-shadow: 0 0 0 0.15rem rgba(10,102,178,0.15);
    }
    footer {
      background: #1A1D23;
      color: #9BA5B3;
    }
    .mobile-header {
      display: none;
    }
    @media (max-width: 992px) {
      .side-nav {
        transform: translateX(-100%);
      }
      .main-content {
        margin-left: 0;
        width: 100%;
      }
      .mobile-header {
        display: flex;
        justify-content: space-between;
        align-items: center;
        height: 60px;
        background: white;
        padding: 0 1.5rem;
        position: fixed;
        top: 0;
        width: 100%;
        z-index: 1040;
        box-shadow: 0 2px 10px rgba(0,0,0,0.05);
      }
      .hero-section {
        margin-top: 60px;
        min-height: 80vh;
        padding: 2rem;
      }
    }
    @media (max-width: 768px) {
      h1 { font-size: 2rem; }
      .section-padding { padding: 60px 0; }
    }