/* roulang page: index */
/* 自定义设计变量与全局重置 */
    :root {
      --primary-deep: #4B0082;
      --primary-bright: #FF6B00;
      --accent-cyan: #00F0FF;
      --bg-warm: #FDF8F2;
      --bg-dark: #121212;
      --card-white: #FFFFFF;
      --text-main: #1E1E1E;
      --text-secondary: #5A5A5A;
      --text-on-dark: #E8E8E8;
      --border-light: rgba(0,0,0,0.06);
      --shadow-card: 0 4px 20px rgba(0,0,0,0.04);
      --shadow-hover: 0 12px 32px rgba(0,0,0,0.08);
      --radius-lg: 20px;
      --radius-btn: 50px;
      --radius-badge: 12px;
      --transition-smooth: 0.25s ease;
      --font-sans: 'Noto Sans SC', system-ui, -apple-system, 'Segoe UI', sans-serif;
      --font-number: 'Inter', 'Noto Sans SC', sans-serif;
    }
    * {
      box-sizing: border-box;
    }
    body {
      margin: 0;
      font-family: var(--font-sans);
      background-color: var(--bg-warm);
      color: var(--text-main);
      line-height: 1.7;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }
    img {
      max-width: 100%;
      display: block;
      height: auto;
    }
    a {
      text-decoration: none;
      color: inherit;
      transition: color var(--transition-smooth);
    }
    button, .btn {
      cursor: pointer;
      font-family: inherit;
    }
    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 24px;
      width: 100%;
    }
    /* 导航栏暗色霓虹风格 */
    .navbar {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 72px;
      background: rgba(18,18,18,0.92);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
      border-bottom: 1px solid rgba(255,255,255,0.15);
      z-index: 100;
      display: flex;
      align-items: center;
    }
    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
    }
    .logo {
      font-weight: 700;
      font-size: 26px;
      background: linear-gradient(135deg, #4B0082 0%, #FF6B00 100%);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
      letter-spacing: -0.3px;
    }
    .nav-links {
      display: flex;
      gap: 32px;
      align-items: center;
    }
    .nav-links a {
      color: rgba(255,255,255,0.8);
      font-weight: 500;
      font-size: 15px;
      padding-bottom: 6px;
      border-bottom: 3px solid transparent;
      transition: all 0.25s;
    }
    .nav-links a:hover, .nav-links a.active {
      color: white;
      border-bottom-color: var(--accent-cyan);
      text-shadow: 0 0 8px rgba(0,240,255,0.6);
    }
    .nav-cta {
      background: var(--primary-bright);
      color: white !important;
      padding: 10px 24px !important;
      border-radius: 50px;
      font-weight: 600;
      box-shadow: 0 4px 12px rgba(255,107,0,0.4);
      border-bottom: none !important;
    }
    .nav-cta:hover {
      background: #e65f00;
      box-shadow: 0 6px 18px rgba(255,107,0,0.6);
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      background: transparent;
      border: none;
      cursor: pointer;
    }
    .hamburger span {
      width: 26px;
      height: 3px;
      background: white;
      border-radius: 3px;
      transition: 0.2s;
    }
    /* 区块间距 */
    section {
      padding: 100px 0;
    }
    /* 按钮系统 */
    .btn-primary {
      background: linear-gradient(135deg, #4B0082 0%, #FF6B00 100%);
      color: white;
      font-weight: 600;
      padding: 14px 36px;
      border-radius: var(--radius-btn);
      display: inline-block;
      transition: all var(--transition-smooth);
      border: none;
      box-shadow: 0 6px 18px rgba(75,0,130,0.3);
    }
    .btn-primary:hover {
      filter: brightness(1.1);
      box-shadow: 0 0 20px rgba(0,240,255,0.5), 0 8px 24px rgba(75,0,130,0.4);
      transform: translateY(-2px);
    }
    .btn-outline {
      background: transparent;
      border: 2px solid #4B0082;
      color: #4B0082;
      font-weight: 600;
      padding: 12px 34px;
      border-radius: var(--radius-btn);
      display: inline-block;
      transition: all var(--transition-smooth);
    }
    .btn-outline:hover {
      background: rgba(75,0,130,0.06);
      border-color: #FF6B00;
      color: #FF6B00;
    }
    /* 卡片 */
    .card {
      background: var(--card-white);
      border-radius: var(--radius-lg);
      padding: 32px;
      box-shadow: var(--shadow-card);
      transition: all 0.3s ease;
      border: 1px solid transparent;
    }
    .card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-hover);
      border-color: #4B0082;
      border-image: linear-gradient(135deg, #4B0082, #FF6B00) 1;
    }
    /* 数据徽章 */
    .data-badge {
      background: rgba(0,0,0,0.65);
      backdrop-filter: blur(8px);
      border-radius: var(--radius-badge);
      padding: 12px 20px;
      color: white;
      display: inline-flex;
      flex-direction: column;
      align-items: center;
    }
    .glow-number {
      font-family: var(--font-number);
      font-weight: 800;
      font-size: 48px;
      color: var(--accent-cyan);
      text-shadow: 0 0 14px rgba(0,240,255,0.6);
      line-height: 1.2;
    }
    /* FAQ手风琴 */
    .faq-item {
      border-radius: 16px;
      margin-bottom: 16px;
      background: #FFFFFF;
      border: 1px solid rgba(0,0,0,0.04);
      transition: 0.2s;
    }
    .faq-question {
      padding: 20px 24px;
      font-weight: 600;
      font-size: 18px;
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
      background: #F9F9F9;
      border-radius: 16px;
    }
    .faq-answer {
      padding: 0 24px 20px;
      display: none;
      color: var(--text-secondary);
      line-height: 1.6;
    }
    .faq-item.active {
      border-color: var(--accent-cyan);
      box-shadow: 0 0 12px rgba(0,240,255,0.2);
    }
    .faq-item.active .faq-question {
      background: white;
    }
    .faq-item.active .faq-answer {
      display: block;
    }
    /* 响应式 */
    @media (max-width: 768px) {
      .nav-links {
        display: none;
        position: absolute;
        top: 72px;
        left: 0;
        width: 100%;
        background: #121212;
        flex-direction: column;
        padding: 24px;
        gap: 20px;
        border-bottom: 2px solid #4B0082;
      }
      .nav-links.open {
        display: flex;
      }
      .hamburger {
        display: flex;
      }
      section {
        padding: 80px 0;
      }
      .hero-grid, .solution-grid, .testimonial-grid {
        flex-direction: column;
      }
      .card {
        padding: 24px;
      }
      h1 {
        font-size: 32px !important;
      }
      h2 {
        font-size: 28px !important;
      }
      .glow-number {
        font-size: 40px;
      }
      .faq-grid {
        grid-template-columns: 1fr;
      }
    }