/* roulang page: index */
:root {
      --primary-color: #1E40AF;
      --secondary-color: #0284C7;
      --accent-color: #10B981;
      --bg-light: #F8FAFC;
      --bg-dark: #0F172A;
      --text-main: #0F172A;
      --text-body: #334155;
      --text-muted: #64748B;
      --border-color: #E2E8F0;
    }
    body {
      font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
      color: var(--text-body);
      background-color: #ffffff;
      overflow-x: hidden;
    }
    .custom-shadow {
      box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.05), 0 2px 4px -2px rgba(0, 0, 0, 0.05);
    }
    .custom-shadow-hover:hover {
      box-shadow: 0 20px 25px -5px rgba(30, 64, 175, 0.09), 0 8px 10px -6px rgba(30, 64, 175, 0.05);
      transform: translateY(-4px);
    }
    .glass-nav {
      background: rgba(255, 255, 255, 0.95);
      backdrop-filter: blur(12px);
    }
    .hero-card-stack {
      perspective: 1000px;
    }
    .hero-card-main {
      transform: rotateY(-3deg) translateZ(20px);
      box-shadow: 0 25px 50px -12px rgba(30, 64, 175, 0.25);
    }
    .hero-card-sub1 {
      transform: rotateY(6deg) translateZ(-10px) translateY(40px);
    }
    .hero-card-sub2 {
      transform: rotateY(-8deg) translateZ(-20px) translateY(-25px);
    }
    .accordion-content {
      transition: max-height 0.3s cubic-bezier(0.4, 0, 0.2, 1), opacity 0.3s ease;
    }