/* roulang page: index */
:root {
      --primary: #0A2540;
      --primary-soft: rgba(10, 37, 64, 0.03);
      --accent: #00C9A7;
      --accent-hover: #00B392;
      --bg: #F4F6FA;
      --card-bg: #FFFFFF;
      --text-main: #1A1A1A;
      --text-muted: #5A6B7F;
      --cta-orange: #FF6B35;
      --border-light: #E2E8F0;
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-input: 6px;
      --shadow-sm: 0 2px 12px rgba(10, 37, 64, 0.06);
      --shadow-hover: 0 8px 24px rgba(10, 37, 64, 0.12);
      --transition: 0.25s ease;
      --max-width: 1280px;
      --spacing-section: 80px;
      --spacing-mobile: 48px;
    }

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

    body {
      font-family: system-ui, -apple-system, 'Segoe UI', Roboto, 'Helvetica Neue', sans-serif;
      background-color: var(--bg);
      color: var(--text-main);
      line-height: 1.7;
      font-weight: 400;
      font-size: 16px;
      scroll-behavior: smooth;
    }

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

    a {
      text-decoration: none;
      color: inherit;
      transition: color var(--transition);
    }

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

    /* 导航栏 */
    .navbar {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      background: #FFFFFF;
      box-shadow: 0 1px 8px rgba(0,0,0,0.02);
      z-index: 1000;
      height: 72px;
      display: flex;
      align-items: center;
      border-bottom: 1px solid var(--border-light);
    }

    .nav-container {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 24px;
    }

    .logo {
      display: flex;
      align-items: center;
      gap: 10px;
      font-weight: 700;
      font-size: 1.5rem;
      color: var(--primary);
      letter-spacing: -0.02em;
    }

    .logo-icon {
      width: 32px;
      height: 32px;
      background: var(--primary);
      clip-path: polygon(50% 0%, 100% 25%, 100% 75%, 50% 100%, 0% 75%, 0% 25%);
      display: flex;
      align-items: center;
      justify-content: center;
      color: white;
      font-size: 1.2rem;
    }

    .nav-menu {
      display: flex;
      align-items: center;
      gap: 32px;
    }

    .nav-link {
      color: var(--text-muted);
      font-weight: 500;
      font-size: 1rem;
      position: relative;
      padding: 8px 0;
      transition: color var(--transition);
    }

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

    .nav-link:hover {
      color: var(--primary);
    }

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

    .btn-primary {
      background: var(--accent);
      color: white;
      border: none;
      padding: 12px 28px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 1rem;
      cursor: pointer;
      transition: background var(--transition), box-shadow var(--transition);
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 6px;
      white-space: nowrap;
    }

    .btn-primary:hover {
      background: var(--accent-hover);
      box-shadow: 0 4px 14px rgba(0, 201, 167, 0.3);
    }

    .btn-outline {
      background: transparent;
      border: 1.5px solid var(--primary);
      color: var(--primary);
      padding: 12px 28px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      transition: all var(--transition);
    }

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

    .btn-cta-orange {
      background: var(--cta-orange);
      color: white;
      border: none;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 700;
      transition: background var(--transition), box-shadow var(--transition);
    }

    .btn-cta-orange:hover {
      background: #e55a2b;
      box-shadow: 0 6px 18px rgba(255, 107, 53, 0.3);
    }

    .hamburger {
      display: none;
      font-size: 1.8rem;
      background: none;
      border: none;
      color: var(--primary);
      cursor: pointer;
    }

    /* Hero */
    .hero {
      padding: 120px 0 80px;
      background: linear-gradient(180deg, #F4F6FA 0%, #FFFFFF 100%);
    }

    .hero-grid {
      display: grid;
      grid-template-columns: 1.2fr 0.8fr;
      gap: 48px;
      align-items: center;
    }

    .hero-left h1 {
      font-size: 44px;
      font-weight: 700;
      letter-spacing: -0.02em;
      color: var(--primary);
      line-height: 1.2;
      margin-bottom: 20px;
    }

    .hero-sub {
      font-size: 18px;
      color: var(--text-muted);
      margin-bottom: 32px;
    }

    .download-buttons {
      display: flex;
      flex-wrap: wrap;
      gap: 16px;
      margin-bottom: 12px;
    }

    .hero-right {
      position: relative;
      display: flex;
      justify-content: center;
    }

    .phone-mock {
      background: var(--card-bg);
      border-radius: 32px;
      box-shadow: var(--shadow-hover);
      padding: 12px;
      transform: rotate(3deg);
      max-width: 280px;
      border: 1px solid var(--border-light);
    }

    .phone-mock img {
      border-radius: 24px;
    }

    .section {
      padding: var(--spacing-section) 0;
    }

    .section-title {
      font-size: 32px;
      font-weight: 700;
      letter-spacing: -0.02em;
      text-align: center;
      margin-bottom: 48px;
      color: var(--primary);
    }

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

    .feature-card {
      background: var(--card-bg);
      padding: 32px;
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-sm);
      transition: transform var(--transition), box-shadow var(--transition);
      text-align: center;
    }

    .feature-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
    }

    .feature-icon {
      font-size: 2.4rem;
      color: var(--accent);
      margin-bottom: 20px;
      background: rgba(0, 201, 167, 0.1);
      width: 64px;
      height: 64px;
      display: flex;
      align-items: center;
      justify-content: center;
      border-radius: 50%;
      margin-left: auto;
      margin-right: auto;
    }

    .feature-card h3 {
      font-size: 20px;
      font-weight: 700;
      margin-bottom: 12px;
    }

    /* 产品瀑布流 */
    .waterfall-item {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 40px;
      align-items: center;
      margin-bottom: 80px;
    }

    .waterfall-item.reverse {
      direction: ltr;
    }

    .waterfall-item.reverse .waterfall-text {
      order: 1;
    }

    .waterfall-img img {
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-sm);
      width: 100%;
    }

    .waterfall-text h3 {
      font-size: 24px;
      margin-bottom: 16px;
    }

    .tag {
      display: inline-block;
      background: rgba(0, 201, 167, 0.1);
      color: var(--accent);
      padding: 4px 12px;
      border-radius: 20px;
      font-size: 14px;
      font-weight: 600;
      margin-top: 12px;
    }

    /* 对比表 */
    .compare-table {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 16px;
      margin-top: 32px;
    }

    .compare-col {
      background: var(--card-bg);
      border-radius: var(--radius-card);
      padding: 28px 20px;
      box-shadow: var(--shadow-sm);
    }

    .compare-col.highlight {
      border-left: 4px solid var(--accent);
      background: #f9fffe;
    }

    .compare-col h4 {
      font-size: 20px;
      margin-bottom: 20px;
    }

    .compare-row {
      display: flex;
      justify-content: space-between;
      padding: 10px 0;
      border-bottom: 1px solid var(--border-light);
    }

    /* 数据区 */
    .stats-band {
      background: var(--primary-soft);
      padding: 64px 0;
    }

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

    .stat-number {
      font-size: 42px;
      font-weight: 700;
      color: var(--accent);
    }

    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }

    details {
      background: var(--card-bg);
      border-radius: var(--radius-card);
      margin-bottom: 16px;
      box-shadow: var(--shadow-sm);
      padding: 20px 24px;
      transition: all var(--transition);
    }

    details[open] {
      box-shadow: var(--shadow-hover);
    }

    summary {
      font-weight: 700;
      font-size: 18px;
      cursor: pointer;
      list-style: none;
      display: flex;
      justify-content: space-between;
      align-items: center;
      color: var(--primary);
    }

    summary i {
      transition: transform 0.2s;
    }

    details[open] summary i {
      transform: rotate(45deg);
    }

    .faq-answer {
      margin-top: 16px;
      color: var(--text-muted);
    }

    /* CTA 横幅 */
    .cta-banner {
      background: var(--primary);
      color: white;
      padding: 64px 0;
      text-align: center;
    }

    .cta-buttons {
      display: flex;
      justify-content: center;
      gap: 20px;
      margin-top: 28px;
      flex-wrap: wrap;
    }

    /* 页脚 */
    .footer {
      background: var(--primary);
      color: #B0C4DE;
      padding: 48px 0 24px;
    }

    .footer-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 32px;
    }

    .footer a {
      color: #B0C4DE;
    }

    .footer a:hover {
      color: var(--accent);
    }

    .copyright {
      border-top: 1px solid rgba(255,255,255,0.1);
      margin-top: 32px;
      padding-top: 20px;
      text-align: center;
      font-size: 14px;
    }

    @media (max-width: 1023px) {
      .hero-grid, .waterfall-item {
        grid-template-columns: 1fr;
      }
      .features-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .compare-table {
        grid-template-columns: 1fr;
      }
      .stats-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .footer-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      h1 { font-size: 36px; }
    }

    @media (max-width: 767px) {
      .nav-menu {
        display: none;
        position: absolute;
        top: 72px;
        left: 0;
        width: 100%;
        background: white;
        flex-direction: column;
        padding: 24px;
        box-shadow: 0 8px 20px rgba(0,0,0,0.05);
      }
      .nav-menu.active {
        display: flex;
      }
      .hamburger {
        display: block;
      }
      .features-grid {
        grid-template-columns: 1fr;
      }
      .section {
        padding: var(--spacing-mobile) 0;
      }
      h1 { font-size: 32px; }
      h2 { font-size: 26px; }
      .download-buttons {
        flex-direction: column;
      }
      .stats-grid {
        grid-template-columns: 1fr;
      }
      .footer-grid {
        grid-template-columns: 1fr;
      }
      .waterfall-item.reverse .waterfall-text {
        order: 0;
      }
    }