/* roulang page: index */
:root {
      --deep-green: #1A3C2A;
      --electric-cyan: #00C9A7;
      --bg-warm: #FAFAF8;
      --card-bg: #FFFFFF;
      --text-primary: #1B1B1B;
      --text-secondary: #4A4A4A;
      --text-muted: #6B6B6B;
      --accent-orange: #FF6B35;
      --border-light: #E8ECEA;
      --border-subtle: #D0D5D2;
      --shadow-sm: 0 1px 3px rgba(0,0,0,0.04), 0 1px 2px rgba(0,0,0,0.06);
      --shadow-hover: 0 8px 24px rgba(26,60,42,0.12);
      --radius-card: 8px;
      --radius-btn: 4px;
      --font-stack: system-ui, -apple-system, "PingFang SC", "Microsoft YaHei", sans-serif;
      --spacing-section: 100px;
    }

    * {
      box-sizing: border-box;
    }

    body {
      font-family: var(--font-stack);
      background-color: var(--bg-warm);
      color: var(--text-primary);
      line-height: 1.7;
      font-size: 16px;
      margin: 0;
      padding: 0;
    }

    h1, h2, h3, h4 {
      font-weight: 700;
      letter-spacing: -0.2px;
    }

    h1 {
      font-size: 48px;
      letter-spacing: -0.5px;
      line-height: 1.2;
    }

    h2 {
      font-size: 34px;
      letter-spacing: 0;
      margin-bottom: 1rem;
    }

    h3 {
      font-size: 22px;
      font-weight: 600;
    }

    h4 {
      font-size: 16px;
      font-weight: 600;
      letter-spacing: 1px;
      text-transform: uppercase;
    }

    a {
      text-decoration: none;
      color: inherit;
      transition: color 0.2s ease;
    }

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

    .container-lg {
      max-width: 1200px;
      margin: 0 auto;
      padding-left: 15px;
      padding-right: 15px;
    }

    /* 导航 */
    .navbar-custom {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 1000;
      background: rgba(250,250,248,0.85);
      backdrop-filter: blur(12px);
      border-bottom: 1px solid transparent;
      transition: background 0.3s, border-color 0.3s;
    }

    .navbar-custom.scrolled {
      background: rgba(250,250,248,0.98);
      border-bottom: 1px solid var(--border-light);
    }

    .navbar-brand-custom {
      font-size: 20px;
      font-weight: 700;
      color: var(--deep-green);
      letter-spacing: 0.5px;
    }

    .nav-link-custom {
      font-size: 14px;
      font-weight: 500;
      color: var(--text-primary);
      margin: 0 16px;
      position: relative;
      padding: 8px 0;
      transition: color 0.2s;
    }

    .nav-link-custom:hover,
    .nav-link-custom.active {
      color: var(--deep-green);
    }

    .nav-link-custom.active::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 100%;
      height: 2px;
      background-color: var(--electric-cyan);
      border-radius: 2px;
    }

    .nav-separator {
      width: 1px;
      height: 16px;
      background-color: var(--border-subtle);
      margin: 0 4px;
    }

    .navbar-toggler-custom {
      border: none;
      background: transparent;
      padding: 4px;
    }

    .navbar-toggler-custom .bar {
      display: block;
      width: 22px;
      height: 1.5px;
      background-color: var(--text-primary);
      margin: 5px 0;
      transition: 0.2s;
    }

    /* Hero */
    .hero-section {
      position: relative;
      background: linear-gradient(135deg, rgba(26,60,42,0.82) 0%, rgba(0,0,0,0.45) 100%), url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      min-height: 90vh;
      display: flex;
      align-items: center;
      color: white;
      overflow: hidden;
    }

    .hero-geo {
      position: absolute;
      right: -80px;
      bottom: 60px;
      width: 300px;
      height: 300px;
      background: repeating-linear-gradient(45deg, transparent, transparent 8px, rgba(0,201,167,0.25) 8px, rgba(0,201,167,0.25) 10px);
      pointer-events: none;
    }

    .hero-title {
      font-size: 48px;
      font-weight: 700;
      line-height: 1.2;
      margin-bottom: 1.2rem;
      max-width: 700px;
    }

    .hero-sub {
      font-size: 18px;
      font-weight: 400;
      color: rgba(255,255,255,0.8);
      max-width: 560px;
      margin-bottom: 2rem;
    }

    .btn-primary-custom {
      background-color: var(--accent-orange);
      border: none;
      color: white;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 15px;
      letter-spacing: 0.5px;
      transition: background 0.2s, transform 0.2s;
    }

    .btn-primary-custom:hover {
      background-color: #e85a2a;
      transform: scale(1.02);
    }

    .btn-outline-light-custom {
      background: transparent;
      border: 1px solid white;
      color: white;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 15px;
      letter-spacing: 0.5px;
      transition: all 0.2s;
    }

    .btn-outline-light-custom:hover {
      background-color: rgba(255,255,255,0.15);
      border-color: white;
    }

    /* 板块 */
    .section-spacing {
      padding: var(--spacing-section) 0;
    }

    .section-title {
      margin-bottom: 3rem;
      color: var(--text-primary);
    }

    .card-custom {
      background: var(--card-bg);
      border: 1px solid var(--border-light);
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-sm);
      transition: transform 0.25s, box-shadow 0.25s, border-color 0.2s;
      height: 100%;
    }

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

    .service-img {
      height: 180px;
      object-fit: cover;
      border-radius: var(--radius-card) var(--radius-card) 0 0;
      position: relative;
    }

    .service-overlay {
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background: rgba(26,60,42,0.1);
      border-radius: var(--radius-card) var(--radius-card) 0 0;
    }

    .data-number {
      font-size: 56px;
      font-weight: 800;
      line-height: 1.1;
    }

    .data-unit {
      font-size: 16px;
      color: var(--text-secondary);
      margin-top: 0.3rem;
    }

    .divider-vertical {
      width: 1px;
      height: 40px;
      background-color: var(--border-subtle);
      margin: 0 20px;
    }

    .case-card .case-img {
      height: 200px;
      object-fit: cover;
      border-radius: var(--radius-card) var(--radius-card) 0 0;
    }

    .case-stripe {
      height: 4px;
      background: var(--electric-cyan);
      transition: height 0.25s;
    }

    .case-card:hover .case-stripe {
      height: 8px;
    }

    .badge-tag {
      background: #EEF2EF;
      color: var(--deep-green);
      font-size: 10px;
      padding: 4px 10px;
      border-radius: 20px;
      font-weight: 600;
    }

    .accordion-custom .accordion-item {
      border: none;
      border-bottom: 1px solid var(--border-light);
      background: transparent;
    }

    .accordion-custom .accordion-button {
      font-weight: 600;
      font-size: 18px;
      color: var(--text-primary);
      background: white;
      box-shadow: none;
      padding: 20px;
      border-left: 4px solid var(--electric-cyan);
    }

    .accordion-custom .accordion-button:not(.collapsed) {
      background-color: #F5F7F5;
      color: var(--deep-green);
      border-left-color: var(--electric-cyan);
    }

    .accordion-custom .accordion-body {
      padding: 0 20px 20px 20px;
      color: var(--text-secondary);
      font-size: 15px;
    }

    .cta-banner {
      background-color: var(--deep-green);
      padding: 80px 0;
    }

    .footer-custom {
      background: #1B1B1B;
      color: #9B9B9B;
      padding: 60px 0 20px;
    }

    .footer-brand {
      color: white;
      font-weight: 700;
      font-size: 18px;
    }

    .footer-link {
      color: #9B9B9B;
      transition: color 0.2s;
    }

    .footer-link:hover {
      color: var(--electric-cyan);
    }

    .footer-bottom {
      border-top: 1px solid #333;
      padding-top: 20px;
      margin-top: 40px;
      font-size: 12px;
      text-align: center;
    }

    @media (max-width: 768px) {
      h1 {
        font-size: 36px;
      }
      .hero-title {
        font-size: 36px;
      }
      .data-number {
        font-size: 40px;
      }
      .section-spacing {
        padding: 70px 0;
      }
      .hero-geo {
        display: none;
      }
    }