/* roulang page: index */
:root {
      --ice: #00E5FF;
      --deep: #0A0E27;
      --glacier: #F0F4F8;
      --aurora: #7B2FBE;
      --energy: #FF6B35;
      --white-rgb: 255, 255, 255;
      --glass-bg: rgba(255, 255, 255, 0.05);
      --glass-border: rgba(255, 255, 255, 0.15);
      --card-shadow: 0 8px 32px rgba(0, 0, 0, 0.12);
      --hover-glow: 0 16px 48px rgba(0, 229, 255, 0.35);
    }

    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }

    body {
      font-family: 'PingFang SC', 'Microsoft YaHei', 'Inter', system-ui, sans-serif;
      background-color: var(--glacier);
      color: #1a1a2e;
      line-height: 1.6;
    }

    /* 沉浸式导航 */
    .navbar {
      background: rgba(10, 14, 39, 0.85);
      backdrop-filter: blur(30px);
      -webkit-backdrop-filter: blur(30px);
      border-bottom: 1px solid rgba(0, 229, 255, 0.3);
      height: 72px;
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 50;
      transition: background 0.3s;
    }

    .nav-link {
      color: rgba(255, 255, 255, 0.8);
      font-weight: 500;
      position: relative;
      padding: 0.5rem 0;
      transition: color 0.2s;
    }

    .nav-link::after {
      content: '';
      position: absolute;
      bottom: -4px;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--ice);
      transition: width 0.3s ease;
    }

    .nav-link:hover {
      color: white;
    }
    .nav-link:hover::after {
      width: 100%;
    }

    .btn-capsule {
      border: 2px solid var(--ice);
      color: var(--ice);
      background: transparent;
      border-radius: 50px;
      padding: 0.5rem 1.5rem;
      font-weight: 600;
      transition: all 0.25s;
      font-size: 0.9rem;
      cursor: pointer;
    }
    .btn-capsule:hover {
      background: var(--ice);
      color: var(--deep);
      box-shadow: 0 0 20px rgba(0, 229, 255, 0.6);
    }

    /* 玻璃拟态卡片 */
    .glass-card {
      background: var(--glass-bg);
      backdrop-filter: blur(20px);
      -webkit-backdrop-filter: blur(20px);
      border: 1px solid var(--glass-border);
      border-radius: 24px;
      box-shadow: var(--card-shadow);
      transition: all 0.3s ease;
    }
    .glass-card:hover {
      border-color: rgba(255, 255, 255, 0.35);
      box-shadow: var(--hover-glow);
      transform: translateY(-4px);
    }

    .btn-primary-glow {
      border: 2px solid var(--ice);
      color: var(--deep);
      background: var(--ice);
      font-weight: 700;
      border-radius: 50px;
      padding: 0.8rem 2.2rem;
      box-shadow: 0 4px 25px rgba(0, 229, 255, 0.55);
      transition: all 0.3s;
      display: inline-block;
      text-align: center;
    }
    .btn-primary-glow:hover {
      background: #33eaff;
      box-shadow: 0 8px 35px rgba(0, 229, 255, 0.8);
      transform: scale(1.02);
    }

    .btn-energy {
      background: var(--energy);
      color: white;
      border: none;
      border-radius: 50px;
      padding: 0.9rem 2.5rem;
      font-weight: 700;
      box-shadow: 0 4px 18px rgba(255, 107, 53, 0.5);
      transition: background 0.25s, box-shadow 0.25s;
    }
    .btn-energy:hover {
      background: #e85a26;
      box-shadow: 0 8px 28px rgba(255, 107, 53, 0.75);
    }

    /* 分割线 */
    .divider-ice {
      height: 2px;
      background: linear-gradient(90deg, transparent, var(--ice), transparent);
      width: 80px;
      margin: 1rem 0;
    }

    /* FAQ 风格 */
    .faq-item {
      border-bottom: 1px solid rgba(0,0,0,0.06);
    }
    .faq-question {
      font-weight: 600;
      font-size: 1.1rem;
      color: var(--deep);
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
      padding: 1.25rem 0;
      border-left: 4px solid var(--ice);
      padding-left: 1.25rem;
      transition: border-color 0.2s;
    }
    .faq-question i {
      color: var(--ice);
      transition: transform 0.3s;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s ease, padding 0.25s;
      background: rgba(255,255,255,0.3);
      padding-left: 2rem;
      color: #2d3748;
      border-radius: 0 0 16px 16px;
    }
    .faq-item.active .faq-question {
      border-left-color: var(--aurora);
    }
    .faq-item.active .faq-answer {
      max-height: 300px;
      padding: 1.25rem 1.25rem 1.25rem 2rem;
    }
    .faq-item.active .faq-question i {
      transform: rotate(180deg);
      color: var(--aurora);
    }

    /* 案例数字滚动示意(静态数字) */
    .stat-number {
      font-family: 'Space Grotesk', sans-serif;
      font-weight: 700;
      font-size: 3rem;
      color: var(--ice);
      line-height: 1.1;
    }

    @media (max-width: 768px) {
      .hero-title {
        font-size: 2.25rem !important;
      }
      .glass-card {
        border-radius: 20px;
      }
    }