/* roulang page: index */
:root {
      --primary: #00E676;
      --primary-hover: #00c853;
      --secondary: #FF5722;
      --secondary-hover: #f4511e;
      --dark-canvas: #0B0E14;
      --dark-card: #151A23;
      --surface: #FFFFFF;
      --surface-muted: #F8FAFC;
      --text-main: #0F172A;
      --text-body: #334155;
      --text-muted: #64748B;
      --border-light: rgba(226, 232, 240, 0.8);
      --border-dark: rgba(255, 255, 255, 0.1);
      --radius-btn: 9999px;
      --radius-card: 1rem;
      --glow-primary: 0 0 25px rgba(0, 230, 118, 0.35);
      --glow-secondary: 0 0 25px rgba(255, 87, 34, 0.35);
    }

    html {
      scroll-behavior: smooth;
      font-family: system-ui, -apple-system, "PingFang SC", "Microsoft YaHei", sans-serif;
    }

    body {
      background-color: var(--surface-muted);
      color: var(--text-body);
      line-height: 1.75;
      overflow-x: hidden;
    }

    .btn-glow-primary:hover {
      box-shadow: var(--glow-primary);
      transform: translateY(-2px);
    }
    .btn-glow-secondary:hover {
      box-shadow: var(--glow-secondary);
      transform: translateY(-2px);
    }

    .dark-section {
      background-color: var(--dark-canvas);
      color: #E2E8F0;
    }

    details > summary::-webkit-details-marker {
      display: none;
    }
    details[open] summary svg {
      transform: rotate(180deg);
    }

    .glass-dark {
      background: rgba(21, 26, 35, 0.75);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
      border: 1px solid var(--border-dark);
    }

    .hero-overlay {
      background: linear-gradient(135deg, rgba(11, 14, 20, 0.94) 0%, rgba(11, 14, 20, 0.82) 60%, rgba(0, 230, 118, 0.18) 100%);
    }

    .transition-custom {
      transition: all 0.3s ease-out;
    }