/* roulang page: index */
:root {
      --brand-primary: #0F5147;
      --brand-hover: #0A3B34;
      --brand-amber: #D97706;
      --brand-dark: #0A1F1C;
      --bg-slate: #F8FAFC;
    }
    html {
      scroll-behavior: smooth;
    }
    body {
      font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Microsoft YaHei", sans-serif;
      color: #334155;
      background-color: #ffffff;
    }
    .hero-bg {
      background-image: linear-gradient(rgba(10, 31, 28, 0.88), rgba(15, 81, 71, 0.85)), url('/assets/images/a174dc6072eb7bdf.webp');
      background-size: cover;
      background-position: center;
    }
    .dark-section-bg {
      background-color: var(--brand-dark);
      background-image: radial-gradient(circle at 10% 20%, rgba(15, 81, 71, 0.3) 0%, transparent 60%);
    }
    .feature-card {
      transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    }
    .feature-card:hover {
      transform: translateY(-4px);
      box-shadow: 0 12px 24px -8px rgba(15, 81, 71, 0.12);
    }
    .accordion-content {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s ease-out;
    }
    .accordion-item.active .accordion-content {
      max-height: 300px;
    }
    .accordion-item.active .accordion-icon {
      transform: rotate(180deg);
    }