/* roulang page: index */
:root {
      --primary: #6C3CEC;
      --primary-hover: #5a2fd6;
      --secondary: #00E5A0;
      --secondary-hover: #00cc8c;
      --bg: #F9FAFC;
      --surface: #FFFFFF;
      --text-primary: #1E1E2D;
      --text-secondary: #6B7280;
      --border: #E5E7EB;
      --radius-card: 12px;
      --radius-btn: 8px;
      --shadow-sm: 0 1px 3px rgba(0,0,0,0.04), 0 1px 2px rgba(0,0,0,0.06);
      --shadow-hover: 0 10px 25px rgba(108,60,236,0.12), 0 4px 10px rgba(0,0,0,0.05);
      --font-sans: "PingFang SC", "Microsoft YaHei", "Noto Sans SC", system-ui, -apple-system, sans-serif;
      --font-mono: "Inter", "SF Pro Display", system-ui, sans-serif;
      --transition: all 0.2s ease;
      --max-width: 1200px;
      --header-height: 64px;
    }

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

    body {
      font-family: var(--font-sans);
      background-color: var(--bg);
      color: var(--text-primary);
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
    }

    img {
      max-width: 100%;
      display: block;
      height: auto;
    }

    a {
      text-decoration: none;
      color: inherit;
    }

    button, input {
      font-family: inherit;
    }

    .container {
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 24px;
    }

    /* 导航栏 */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: var(--header-height);
      background: rgba(255, 255, 255, 0.85);
      backdrop-filter: blur(12px);
      z-index: 1000;
      transition: var(--transition);
      border-bottom: 1px solid transparent;
      display: flex;
      align-items: center;
    }

    .header.scrolled {
      background: rgba(255, 255, 255, 0.95);
      box-shadow: 0 4px 20px rgba(0,0,0,0.04);
      border-bottom: 1px solid var(--border);
    }

    .nav-bar {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
    }

    .logo {
      display: flex;
      align-items: center;
      gap: 10px;
      font-weight: 700;
      font-size: 1.5rem;
      color: var(--primary);
      letter-spacing: -0.5px;
    }

    .logo-icon {
      width: 36px;
      height: 36px;
      background: linear-gradient(135deg, var(--primary) 0%, #9d5cf0 100%);
      border-radius: 10px;
      display: flex;
      align-items: center;
      justify-content: center;
      color: white;
      font-size: 20px;
    }

    .nav-links {
      display: flex;
      gap: 28px;
      align-items: center;
      list-style: none;
    }

    .nav-links a {
      font-weight: 500;
      color: var(--text-secondary);
      font-size: 0.95rem;
      transition: var(--transition);
      position: relative;
      padding: 8px 0;
    }

    .nav-links a:hover,
    .nav-links a.active {
      color: var(--primary);
    }

    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--primary);
      transition: var(--transition);
    }

    .nav-links a:hover::after,
    .nav-links a.active::after {
      width: 100%;
    }

    .mobile-toggle {
      display: none;
      background: none;
      border: none;
      font-size: 28px;
      color: var(--text-primary);
      cursor: pointer;
      z-index: 1001;
    }

    /* 移动端导航 */
    .mobile-menu {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 100vh;
      background: rgba(0, 0, 0, 0.9);
      backdrop-filter: blur(20px);
      display: flex;
      align-items: center;
      justify-content: center;
      z-index: 999;
      opacity: 0;
      pointer-events: none;
      transition: opacity 0.3s ease;
    }

    .mobile-menu.active {
      opacity: 1;
      pointer-events: auto;
    }

    .mobile-menu ul {
      list-style: none;
      text-align: center;
    }

    .mobile-menu li {
      margin: 28px 0;
    }

    .mobile-menu a {
      color: white;
      font-size: 2rem;
      font-weight: 600;
      letter-spacing: 1px;
    }

    .mobile-close {
      position: absolute;
      top: 28px;
      right: 28px;
      background: none;
      border: none;
      color: white;
      font-size: 36px;
      cursor: pointer;
    }

    /* 通用区块 */
    section {
      padding: 80px 0;
    }

    .section-title {
      font-size: 2.2rem;
      font-weight: 700;
      margin-bottom: 16px;
      color: var(--text-primary);
      letter-spacing: -0.5px;
    }

    .section-sub {
      color: var(--text-secondary);
      font-size: 1.1rem;
      margin-bottom: 48px;
      max-width: 600px;
    }

    .grid-3 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }

    .grid-4 {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
    }

    .card {
      background: var(--surface);
      border-radius: var(--radius-card);
      padding: 28px;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
      border: 1px solid var(--border);
    }

    .card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-hover);
    }

    /* Hero */
    .hero {
      padding: 140px 0 100px;
      background: radial-gradient(circle at 30% 40%, rgba(108,60,236,0.06) 0%, transparent 60%);
    }

    .hero-grid {
      display: flex;
      align-items: center;
      gap: 60px;
    }

    .hero-left {
      flex: 1;
    }

    .hero-right {
      flex: 1;
    }

    .hero-right img {
      border-radius: 24px;
      box-shadow: 0 25px 50px -12px rgba(0,0,0,0.15);
      width: 100%;
    }

    h1 {
      font-size: 3.2rem;
      font-weight: 700;
      line-height: 1.2;
      background: linear-gradient(to right, var(--primary), var(--secondary));
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
    }

    .hero-sub {
      font-size: 1.2rem;
      color: var(--text-secondary);
      margin: 20px 0 32px;
    }

    .btn-group {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }

    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      height: 48px;
      padding: 0 28px;
      border-radius: var(--radius-btn);
      font-weight: 500;
      font-size: 1rem;
      transition: var(--transition);
      cursor: pointer;
      border: none;
      text-decoration: none;
    }

    .btn-primary {
      background: var(--primary);
      color: white;
    }

    .btn-primary:hover {
      background: var(--primary-hover);
      box-shadow: 0 8px 18px rgba(108,60,236,0.3);
    }

    .btn-outline {
      border: 2px solid var(--primary);
      color: var(--primary);
      background: transparent;
    }

    .btn-outline:hover {
      background: rgba(108,60,236,0.05);
    }

    .btn-secondary {
      background: var(--secondary);
      color: #1E1E2D;
      font-weight: 600;
    }

    .btn-secondary:hover {
      background: var(--secondary-hover);
    }

    /* 优势卡片 */
    .adv-card {
      text-align: left;
      background: #F3F4F6;
      border: none;
    }

    .adv-icon {
      font-size: 36px;
      margin-bottom: 16px;
      color: var(--primary);
    }

    /* 功能标签切换风格 */
    .feature-tabs {
      display: flex;
      gap: 16px;
      margin-bottom: 40px;
      flex-wrap: wrap;
    }

    .tab-btn {
      padding: 10px 24px;
      border-radius: 30px;
      background: white;
      border: 1px solid var(--border);
      font-weight: 500;
      cursor: pointer;
      transition: var(--transition);
    }

    .tab-btn.active {
      background: var(--primary);
      color: white;
      border-color: var(--primary);
    }

    .features-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }

    .feature-img {
      height: 140px;
      background: #EEF2FF;
      border-radius: 12px;
      margin-bottom: 16px;
      overflow: hidden;
    }

    .feature-img img {
      width: 100%;
      height: 100%;
      object-fit: cover;
    }

    /* 场景横向滚动 */
    .scenario-scroll {
      display: flex;
      gap: 24px;
      overflow-x: auto;
      padding-bottom: 10px;
      scroll-snap-type: x mandatory;
    }

    .scenario-card {
      min-width: 300px;
      background: white;
      border-radius: var(--radius-card);
      padding: 24px;
      box-shadow: 0 8px 20px rgba(0,0,0,0.04);
    }

    /* 案例 */
    .case-card {
      background: #F9FAFC;
    }

    .case-logo {
      width: 48px;
      height: 48px;
      background: #ddd;
      border-radius: 50%;
      margin-bottom: 12px;
    }

    .case-number {
      font-size: 2rem;
      font-weight: 700;
      color: var(--secondary);
    }

    /* 价格卡片 */
    .pricing-card {
      text-align: center;
    }

    .pricing-card.featured {
      background: var(--primary);
      color: white;
      transform: scale(1.02);
    }

    .pricing-card.featured .btn {
      background: white;
      color: var(--primary);
    }

    /* FAQ */
    .faq-item {
      border-bottom: 1px solid var(--border);
    }

    .faq-question {
      width: 100%;
      text-align: left;
      padding: 20px 0;
      font-weight: 600;
      font-size: 1.1rem;
      background: none;
      border: none;
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
    }

    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      color: var(--text-secondary);
    }

    .faq-answer.open {
      max-height: 200px;
      padding-bottom: 16px;
    }

    /* CTA 尾区 */
    .cta-dark {
      background: #1E1E2D;
      color: white;
      text-align: center;
      border-radius: 24px;
      padding: 64px 24px;
    }

    .cta-form {
      display: flex;
      gap: 12px;
      max-width: 480px;
      margin: 32px auto 0;
    }

    .cta-form input {
      flex: 1;
      padding: 0 20px;
      border-radius: var(--radius-btn);
      border: none;
      background: white;
    }

    /* 页脚 */
    .footer {
      background: #111827;
      color: #9CA3AF;
      padding: 60px 0 30px;
    }

    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
    }

    @media (max-width: 1024px) {
      .grid-4, .grid-3, .features-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .hero-grid {
        flex-direction: column;
      }
      h1 {
        font-size: 2.6rem;
      }
    }

    @media (max-width: 768px) {
      .nav-links {
        display: none;
      }
      .mobile-toggle {
        display: block;
      }
      .grid-4, .grid-3, .features-grid, .footer-grid {
        grid-template-columns: 1fr;
      }
      .btn-group {
        flex-direction: column;
      }
    }