/* roulang page: index */
:root {
      --bg-dark: #0b0f17;
      --bg-darker: #06090e;
      --card-dark: #131b29;
      --text-main: #f8fafc;
      --text-muted: #94a3b8;
      --accent-cyan: #0ea5e9;
      --accent-emerald: #10b981;
      --border-dark: #1e293b;
      --border-cyan: #0284c7;
    }
    html {
      scroll-behavior: smooth;
      background-color: var(--bg-dark);
      color: var(--text-main);
      font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
    }
    body {
      overflow-x: hidden;
      margin: 0;
      padding: 0;
    }
    .hero-glow {
      background: radial-gradient(circle at 50% 25%, rgba(14, 165, 233, 0.18) 0%, rgba(11, 15, 23, 0) 70%);
    }
    .tech-border {
      border: 1px solid var(--border-dark);
      transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    }
    .tech-border:hover {
      border-color: var(--accent-cyan);
      transform: translateY(-2px);
      box-shadow: 0 12px 24px -10px rgba(14, 165, 233, 0.25);
    }
    .accordion-content {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s ease-out;
    }
    .accordion-content.open {
      max-height: 400px;
    }
    .btn-gradient {
      background: linear-gradient(135deg, #0ea5e9 0%, #0284c7 100%);
    }
    .btn-gradient:hover {
      background: linear-gradient(135deg, #38bdf8 0%, #0369a1 100%);
    }
    .custom-scrollbar::-webkit-scrollbar {
      height: 6px;
    }
    .custom-scrollbar::-webkit-scrollbar-track {
      background: #0f172a;
    }
    .custom-scrollbar::-webkit-scrollbar-thumb {
      background: #334155;
      border-radius: 3px;
    }