/* roulang page: index */
:root {
      --primary: #1E40AF;
      --accent: #2563EB;
      --sky: #0EA5E9;
      --bg-base: #F8FAFC;
      --text-main: #0F172A;
      --text-body: #334155;
      --text-muted: #64748B;
      --border-color: #E2E8F0;
      --radius-box: 1rem;
      --shadow-soft: 0 4px 20px -2px rgba(15, 23, 42, 0.06);
    }
    
    body {
      font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Microsoft YaHei", sans-serif;
      background-color: #ffffff;
      color: var(--text-body);
      line-height: 1.6;
    }

    .glass-nav {
      background: rgba(255, 255, 255, 0.95);
      backdrop-filter: blur(10px);
      -webkit-backdrop-filter: blur(10px);
    }

    .card-modern {
      background: #ffffff;
      border: 1px solid #f1f5f9;
      border-radius: var(--radius-box);
      box-shadow: 0 1px 3px rgba(0,0,0,0.05), 0 10px 15px -5px rgba(0,0,0,0.02);
      transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
    }

    .card-modern:hover {
      transform: translateY(-4px);
      box-shadow: 0 20px 25px -5px rgba(30, 64, 175, 0.08), 0 8px 10px -6px rgba(30, 64, 175, 0.04);
      border-color: #cbd5e1;
    }

    .btn-gradient {
      background: linear-gradient(135deg, #1E40AF 0%, #2563EB 100%);
      transition: all 0.25s ease;
    }
    .btn-gradient:hover {
      background: linear-gradient(135deg, #1d4ed8 0%, #1e40af 100%);
      box-shadow: 0 10px 15px -3px rgba(37, 99, 235, 0.35);
      transform: translateY(-1px);
    }

    .btn-light {
      background-color: #ffffff;
      border: 1px solid #cbd5e1;
      color: #1e293b;
      transition: all 0.2s ease;
    }
    .btn-light:hover {
      background-color: #f8fafc;
      border-color: #94a3b8;
      color: #1e40af;
    }

    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s ease-out, opacity 0.25s ease;
      opacity: 0;
    }
    .faq-item.active .faq-answer {
      opacity: 1;
    }
    .faq-item.active .faq-icon {
      transform: rotate(180deg);
    }