/* roulang page: index */
:root {
      --bg-deep: #0B0C10;
      --accent-neon-orange: #FF6B35;
      --accent-neon-cyan: #00F0FF;
      --card-bg: #1F2128;
      --bg-light: #1A1C23;
      --text-primary: #EAEAEA;
      --text-secondary: #9CA3AF;
      --border-dim: rgba(255,255,255,0.08);
      --border-neon: rgba(255,107,53,0.2);
      --shadow-card: 0 8px 32px rgba(0,0,0,0.4);
      --radius-card: 12px;
      --radius-btn: 8px;
      --transition-smooth: all 0.25s ease;
    }

    * {
      box-sizing: border-box;
    }

    body {
      margin: 0;
      font-family: 'Inter', system-ui, -apple-system, 'Segoe UI', Roboto, 'Helvetica Neue', sans-serif;
      background-color: var(--bg-deep);
      color: var(--text-primary);
      line-height: 1.8;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }

    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 24px;
    }

    @media (max-width: 768px) {
      .container {
        padding: 0 16px;
      }
    }

    /* 导航 */
    .navbar {
      position: sticky;
      top: 0;
      z-index: 50;
      background: rgba(11, 12, 16, 0.92);
      backdrop-filter: blur(12px);
      height: 72px;
      border-bottom: 2px solid transparent;
      background-image: linear-gradient(rgba(11,12,16,0.92), rgba(11,12,16,0.92)), linear-gradient(90deg, var(--accent-neon-orange), var(--accent-neon-cyan));
      background-origin: border-box;
      background-clip: padding-box, border-box;
      transition: var(--transition-smooth);
    }

    .nav-link {
      color: var(--text-primary);
      text-decoration: none;
      font-weight: 500;
      transition: var(--transition-smooth);
      position: relative;
      padding: 8px 0;
    }

    .nav-link:hover {
      color: var(--accent-neon-cyan);
    }

    .nav-link.active {
      color: var(--accent-neon-orange);
    }

    .nav-link.active::after {
      content: '';
      position: absolute;
      bottom: -4px;
      left: 0;
      width: 100%;
      height: 2px;
      background: var(--accent-neon-orange);
      box-shadow: 0 0 8px var(--accent-neon-orange);
    }

    .mobile-menu {
      background: rgba(11, 12, 16, 0.98);
      backdrop-filter: blur(16px);
    }

    /* 霓虹强调线 */
    .neon-divider {
      width: 60px;
      height: 3px;
      background: var(--accent-neon-orange);
      margin: 12px 0 24px;
      box-shadow: 0 0 12px rgba(255,107,53,0.7);
    }

    /* 卡片 */
    .card {
      background: var(--card-bg);
      border: 1px solid rgba(255,107,53,0.15);
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-card);
      transition: var(--transition-smooth);
    }

    .card:hover {
      border-color: var(--accent-neon-orange);
      box-shadow: 0 0 18px rgba(255,107,53,0.5);
      transform: translateY(-4px);
    }

    /* 按钮 */
    .btn-primary {
      background: var(--accent-neon-orange);
      color: #0B0C10;
      font-weight: 600;
      border-radius: var(--radius-btn);
      padding: 14px 32px;
      transition: var(--transition-smooth);
      display: inline-block;
      text-align: center;
      border: none;
      cursor: pointer;
      box-shadow: 0 4px 12px rgba(255,107,53,0.3);
    }

    .btn-primary:hover {
      background: #FF8C5A;
      box-shadow: 0 0 20px rgba(255,107,53,0.7);
    }

    .btn-outline {
      background: transparent;
      border: 1px solid var(--accent-neon-cyan);
      color: var(--accent-neon-cyan);
      font-weight: 600;
      border-radius: var(--radius-btn);
      padding: 14px 32px;
      transition: var(--transition-smooth);
      display: inline-block;
      text-align: center;
      cursor: pointer;
    }

    .btn-outline:hover {
      background: rgba(0,240,255,0.1);
      box-shadow: 0 0 14px rgba(0,240,255,0.4);
    }

    /* 标签胶囊 */
    .tag {
      background: rgba(0,240,255,0.15);
      color: var(--accent-neon-cyan);
      border-radius: 20px;
      padding: 4px 14px;
      font-size: 0.8rem;
      font-weight: 500;
      display: inline-block;
    }

    /* FAQ */
    .faq-item {
      border-bottom: 1px solid rgba(255,255,255,0.06);
      transition: var(--transition-smooth);
    }
    .faq-question {
      cursor: pointer;
      position: relative;
      padding-left: 16px;
    }
    .faq-question::before {
      content: '';
      position: absolute;
      left: 0;
      top: 8px;
      height: 24px;
      width: 3px;
      background: var(--accent-neon-orange);
      box-shadow: 0 0 8px var(--accent-neon-orange);
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s ease, background 0.2s;
      background: transparent;
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      background: rgba(255,107,53,0.04);
    }

    /* 表单发光 */
    input:focus, textarea:focus {
      outline: none;
      border-color: var(--accent-neon-cyan);
      box-shadow: 0 0 12px rgba(0,240,255,0.5);
    }

    /* 图片微切角 */
    .hero-image {
      clip-path: polygon(2% 0%, 100% 0, 98% 100%, 0% 100%);
      border: 2px solid rgba(0,240,255,0.35);
    }