/* roulang page: index */
:root {
      --bg-dark: #070B19;
      --bg-gradient: radial-gradient(circle at 50% 10%, #0d1b3e 0%, #070B19 75%);
      --primary: #1E6FFF;
      --cyan: #00F2FE;
      --orange: #FF5E3A;
      --card-bg: rgba(15, 23, 42, 0.72);
      --card-border: rgba(255, 255, 255, 0.08);
      --card-highlight: rgba(0, 242, 254, 0.25);
    }
    html {
      scroll-behavior: smooth;
    }
    body {
      background-color: var(--bg-dark);
      background-image: var(--bg-gradient);
      color: #F8FAFC;
      font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", PingFang SC, "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
      overflow-x: hidden;
    }
    .grid-mesh {
      background-image: linear-gradient(to right, rgba(255,255,255,0.03) 1px, transparent 1px),
                        linear-gradient(to bottom, rgba(255,255,255,0.03) 1px, transparent 1px);
      background-size: 40px 40px;
    }
    .glass-card {
      background: var(--card-bg);
      backdrop-filter: blur(16px);
      -webkit-backdrop-filter: blur(16px);
      border: 1px solid var(--card-border);
      box-shadow: 0 20px 40px -15px rgba(0, 0, 0, 0.5);
      transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
    }
    .glass-card:hover {
      border-color: var(--card-highlight);
      transform: translateY(-3px);
      box-shadow: 0 25px 50px -12px rgba(0, 242, 254, 0.15);
    }
    .glow-btn-primary {
      background: linear-gradient(135deg, #1E6FFF 0%, #00F2FE 100%);
      color: #040711;
      font-weight: 600;
      box-shadow: 0 0 20px rgba(0, 242, 254, 0.35);
      transition: all 0.25s ease;
    }
    .glow-btn-primary:hover {
      box-shadow: 0 0 32px rgba(0, 242, 254, 0.65);
      transform: translateY(-2px);
    }
    .glow-btn-secondary {
      background: rgba(30, 111, 255, 0.08);
      border: 1px solid rgba(30, 111, 255, 0.5);
      color: #00F2FE;
      transition: all 0.25s ease;
    }
    .glow-btn-secondary:hover {
      background: rgba(30, 111, 255, 0.25);
      border-color: #00F2FE;
      box-shadow: 0 0 20px rgba(30, 111, 255, 0.4);
      transform: translateY(-2px);
    }
    .accordion-content {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s ease-out, padding 0.35s ease;
    }
    .accordion-item.active .accordion-content {
      max-height: 240px;
    }
    .accordion-item.active .accordion-icon {
      transform: rotate(45deg);
      color: #00F2FE;
    }
    .timeline-dot {
      box-shadow: 0 0 14px #00F2FE;
    }