/* roulang page: index */
/* 设计变量与全局重置 */
    :root {
      --deep-black: #0A0E17;
      --card-bg: #1A1F2B;
      --metal-border: #2C3540;
      --accent-orange: #FF4D00;
      --accent-cyan: #00E5FF;
      --hover-orange: #FF6A2C;
      --text-white: #FFFFFF;
      --text-light-gray: #B0B8C1;
      --dark-purple: #1A1025;
      --shadow-glow: 0 0 20px rgba(255,77,0,0.3);
    }
    * {
      box-sizing: border-box;
    }
    body {
      margin: 0;
      font-family: 'Inter', 'PingFang SC', 'Microsoft YaHei', system-ui, -apple-system, sans-serif;
      background-color: var(--deep-black);
      color: #E0E4E9;
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
    }
    .container {
      max-width: 1280px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 1.5rem;
      padding-right: 1.5rem;
    }
    /* 导航栏 */
    .navbar {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 50;
      backdrop-filter: blur(12px);
      background-color: rgba(10, 14, 23, 0.8);
      border-bottom: 1px solid rgba(44, 53, 64, 0.5);
      transition: background-color 0.3s ease;
    }
    .nav-blur {
      background-color: rgba(10, 14, 23, 0.95);
    }
    .nav-link {
      color: #B0B8C1;
      font-weight: 500;
      letter-spacing: 0.3px;
      transition: color 0.2s, border-color 0.2s;
      border-bottom: 2px solid transparent;
    }
    .nav-link:hover {
      color: var(--accent-orange);
    }
    .logo-text {
      font-weight: 800;
      font-size: 1.8rem;
      letter-spacing: -0.5px;
      color: white;
      display: flex;
      align-items: center;
      gap: 0.25rem;
    }
    .logo-text i {
      color: var(--accent-orange);
      font-size: 1.8rem;
      text-shadow: 0 0 8px var(--accent-orange);
    }
    /* 汉堡菜单 */
    .mobile-menu {
      background-color: #0A0E17;
      border-left: 2px solid var(--accent-orange);
    }
    /* 按钮组件 */
    .btn-primary {
      background-color: var(--accent-orange);
      color: white;
      font-weight: 600;
      border-radius: 6px;
      padding: 0.75rem 2rem;
      transition: all 0.25s;
      border: none;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      box-shadow: 0 4px 12px rgba(255,77,0,0.4);
    }
    .btn-primary:hover {
      background-color: var(--hover-orange);
      box-shadow: 0 0 18px rgba(0,229,255,0.5);
      transform: translateY(-2px);
    }
    .btn-ghost {
      border: 1px solid var(--accent-cyan);
      color: var(--accent-cyan);
      background: transparent;
      font-weight: 600;
      border-radius: 6px;
      padding: 0.75rem 2rem;
      transition: all 0.25s;
    }
    .btn-ghost:hover {
      background-color: rgba(0,229,255,0.1);
      color: white;
      border-color: white;
    }
    /* 卡片规范 */
    .card-glow {
      background-color: var(--card-bg);
      border: 1px solid var(--metal-border);
      border-radius: 12px;
      transition: all 0.3s ease;
    }
    .card-glow:hover {
      border-color: var(--accent-orange);
      box-shadow: var(--shadow-glow);
      transform: translateY(-4px);
    }
    /* 霓虹光效线条 */
    .neon-cyan-border {
      border-left: 3px solid var(--accent-cyan);
    }
    /* FAQ 手风琴 */
    details summary {
      cursor: pointer;
      list-style: none;
      display: flex;
      align-items: center;
      justify-content: space-between;
    }
    details summary::-webkit-details-marker {
      display: none;
    }
    .faq-q {
      color: var(--accent-orange);
      font-weight: 700;
      margin-right: 0.75rem;
    }
    /* 表单 */
    input[type="email"] {
      background-color: #0A0E17;
      border: 1px solid var(--metal-border);
      color: white;
      border-radius: 6px;
      padding: 0.75rem 1rem;
      transition: border 0.2s;
    }
    input[type="email"]:focus {
      outline: none;
      border-color: var(--accent-cyan);
      box-shadow: 0 0 10px rgba(0,229,255,0.3);
    }
    /* 响应式调整 */
    @media (max-width: 768px) {
      .hero-title {
        font-size: 2.2rem !important;
      }
      .grid-cols-4 {
        grid-template-columns: repeat(2, minmax(0, 1fr)) !important;
      }
    }
    @media (max-width: 520px) {
      .grid-cols-4, .grid-cols-3 {
        grid-template-columns: 1fr !important;
      }
    }
    /* 动态网格背景装饰 */
    .hero-bg-mesh {
      background-image: radial-gradient(circle at 30% 40%, rgba(255,77,0,0.08) 0%, transparent 35%), 
                        linear-gradient(45deg, #0A0E17 0%, #1A1025 100%);
    }
    .section-divider {
      height: 1px;
      background: linear-gradient(90deg, transparent, #2C3540, var(--accent-orange), #2C3540, transparent);
      margin: 0 auto;
      width: 80%;
    }