/* roulang page: index */
:root {
      --bg-dark: #0b0f19;
      --bg-card: rgba(17, 24, 39, 0.72);
      --border-glow: rgba(59, 130, 246, 0.28);
      --primary-blue: #2563eb;
      --primary-cyan: #06b6d4;
      --accent-gold: #f59e0b;
      --text-main: #f9fafb;
      --text-muted: #9ca3af;
    }

    html {
      scroll-behavior: smooth;
    }

    body {
      background-color: var(--bg-dark);
      color: var(--text-main);
      font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
      overflow-x: hidden;
    }

    .glass-card {
      background: var(--bg-card);
      backdrop-filter: blur(16px);
      -webkit-backdrop-filter: blur(16px);
      border: 1px solid rgba(255, 255, 255, 0.1);
      box-shadow: 0 8px 32px 0 rgba(0, 0, 0, 0.36);
      transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
    }
    .glass-card:hover {
      border-color: rgba(59, 130, 246, 0.5);
      box-shadow: 0 12px 40px 0 rgba(37, 99, 235, 0.22);
      transform: translateY(-3px);
    }

    .btn-glow-primary {
      background: linear-gradient(135deg, #2563eb 0%, #06b6d4 100%);
      box-shadow: 0 0 20px rgba(37, 99, 235, 0.45);
      transition: all 0.25s ease-in-out;
    }
    .btn-glow-primary:hover {
      box-shadow: 0 0 28px rgba(6, 182, 212, 0.65);
      transform: translateY(-2px);
    }
    .btn-glow-primary:active {
      transform: scale(0.98);
    }

    .btn-glow-gold {
      background: linear-gradient(135deg, #f59e0b 0%, #d97706 100%);
      box-shadow: 0 0 20px rgba(245, 158, 11, 0.35);
      transition: all 0.25s ease-in-out;
    }
    .btn-glow-gold:hover {
      box-shadow: 0 0 28px rgba(245, 158, 11, 0.6);
      transform: translateY(-2px);
    }

    .nav-blur {
      background: rgba(11, 15, 25, 0.88);
      backdrop-filter: blur(14px);
      -webkit-backdrop-filter: blur(14px);
      border-bottom: 1px solid rgba(255, 255, 255, 0.08);
    }

    /* 手风琴平滑动效 */
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s ease-out;
    }
    .faq-item.active .faq-answer {
      max-height: 280px;
    }
    .faq-item.active .faq-arrow {
      transform: rotate(180deg);
    }

    /* 卡片堆叠 Hero 样式 */
    .hero-stack-container {
      perspective: 1000px;
    }
    .hero-stack-main {
      z-index: 20;
      transform: translateY(0);
      box-shadow: 0 20px 50px rgba(0, 0, 0, 0.6), 0 0 35px rgba(37, 99, 235, 0.3);
    }
    .hero-stack-side-left {
      z-index: 10;
      transform: translate(-30px, 24px) scale(0.92);
      opacity: 0.82;
    }
    .hero-stack-side-right {
      z-index: 10;
      transform: translate(30px, 24px) scale(0.92);
      opacity: 0.82;
    }
    @media (max-width: 1024px) {
      .hero-stack-side-left, .hero-stack-side-right {
        display: none;
      }
      .hero-stack-main {
        transform: none;
      }
    }