/* roulang page: index */
:root {
      --bg-primary: #060913;
      --bg-secondary: #0c1222;
      --card-bg: rgba(15, 23, 42, 0.7);
      --card-border: rgba(56, 189, 248, 0.16);
      --card-hover-border: rgba(56, 189, 248, 0.55);
      --glow-blue: rgba(14, 165, 233, 0.35);
      --glow-cyan: rgba(6, 182, 212, 0.35);
      --text-main: #f8fafc;
      --text-muted: #94a3b8;
    }
    html {
      scroll-behavior: smooth;
      font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
      background-color: var(--bg-primary);
      color: var(--text-main);
    }
    body {
      overflow-x: hidden;
      margin: 0;
      padding: 0;
      background: radial-gradient(circle at 50% 0%, #111e3b 0%, #060913 70%);
      background-attachment: fixed;
    }
    .glass-card {
      background: var(--card-bg);
      backdrop-filter: blur(16px);
      -webkit-backdrop-filter: blur(16px);
      border: 1px solid var(--card-border);
      border-radius: 1rem;
      transition: all 0.3s ease;
    }
    .glass-card:hover {
      border-color: var(--card-hover-border);
      box-shadow: 0 10px 30px -10px var(--glow-blue);
      transform: translateY(-2px);
    }
    .glow-btn-primary {
      background: linear-gradient(135deg, #0ea5e9, #6366f1);
      box-shadow: 0 0 24px rgba(14, 165, 233, 0.4);
      transition: all 0.25s ease;
    }
    .glow-btn-primary:hover {
      box-shadow: 0 0 32px rgba(14, 165, 233, 0.7);
      transform: scale(1.02);
    }
    .glow-btn-cyan {
      background: linear-gradient(135deg, #06b6d4, #0284c7);
      box-shadow: 0 0 24px rgba(6, 182, 212, 0.35);
      transition: all 0.25s ease;
    }
    .glow-btn-cyan:hover {
      box-shadow: 0 0 32px rgba(6, 182, 212, 0.65);
      transform: scale(1.02);
    }
    .text-gradient-cyan {
      background: linear-gradient(to right, #38bdf8, #818cf8);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
    }
    .section-divider {
      height: 1px;
      background: linear-gradient(90deg, transparent, rgba(56, 189, 248, 0.2), transparent);
    }
    details summary::-webkit-details-marker {
      display: none;
    }