/* roulang page: index */
:root {
      --primary: #0A1F3F;
      --accent: #00E5A1;
      --accent-hover: #00C98C;
      --bg: #F7F9FC;
      --surface: #FFFFFF;
      --text: #1E2A3A;
      --text-secondary: #5E6F82;
      --border: #E2E8F0;
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-container: 16px;
      --shadow-sm: 0 4px 20px rgba(10,31,63,0.06);
      --shadow-hover: 0 8px 30px rgba(10,31,63,0.12);
      --font-mono: 'DIN Alternate', 'Roboto Mono', 'SF Mono', monospace;
    }

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

    body {
      font-family: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", "Noto Sans SC", sans-serif;
      background-color: var(--bg);
      color: var(--text);
      line-height: 1.5;
      -webkit-font-smoothing: antialiased;
      scroll-behavior: smooth;
    }

    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
    }

    /* 导航 */
    .main-header {
      position: sticky;
      top: 0;
      z-index: 50;
      background: rgba(255,255,255,0.92);
      backdrop-filter: blur(12px);
      height: 72px;
      display: flex;
      align-items: center;
      box-shadow: 0 1px 0 var(--border);
      padding: 0 24px;
    }

    .nav-container {
      max-width: 1200px;
      width: 100%;
      margin: 0 auto;
      display: flex;
      justify-content: space-between;
      align-items: center;
    }

    .logo {
      font-size: 1.8rem;
      font-weight: 700;
      color: var(--primary);
      text-decoration: none;
      letter-spacing: -0.5px;
      white-space: nowrap;
    }

    .logo span {
      color: var(--accent);
    }

    .desktop-nav {
      display: flex;
      gap: 28px;
      align-items: center;
    }

    .nav-link {
      text-decoration: none;
      font-weight: 500;
      color: var(--text);
      padding: 8px 14px;
      border-radius: 24px;
      transition: all 0.2s ease;
      font-size: 0.95rem;
    }

    .nav-link:hover {
      background: rgba(0,229,161,0.08);
      color: var(--accent-hover);
    }

    .nav-link.active {
      background: rgba(0,229,161,0.15);
      color: var(--accent);
      font-weight: 600;
    }

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

    /* 移动端底部导航 */
    .mobile-bottom-nav {
      display: none;
      position: fixed;
      bottom: 0;
      left: 0;
      right: 0;
      background: white;
      border-top: 1px solid var(--border);
      padding: 8px 12px;
      justify-content: space-around;
      z-index: 55;
      box-shadow: 0 -2px 10px rgba(0,0,0,0.03);
    }

    .mobile-bottom-nav a {
      display: flex;
      flex-direction: column;
      align-items: center;
      font-size: 0.7rem;
      color: var(--text-secondary);
      text-decoration: none;
      gap: 4px;
    }

    .mobile-bottom-nav i {
      font-size: 1.2rem;
    }

    /* 区块通用 */
    section {
      padding: 100px 0;
    }

    .section-title {
      font-size: 2.25rem;
      font-weight: 600;
      color: var(--primary);
      margin-bottom: 12px;
      letter-spacing: -0.3px;
    }

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

    /* 按钮 */
    .btn {
      display: inline-block;
      font-weight: 600;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      text-decoration: none;
      transition: all 0.3s ease;
      cursor: pointer;
      border: none;
      font-size: 1rem;
      text-align: center;
    }

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

    .btn-primary:hover {
      background: var(--accent-hover);
      transform: translateY(-1px);
    }

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

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

    /* Hero */
    .hero {
      background-color: #F7F9FC;
      background-image: radial-gradient(circle at 20% 30%, rgba(0,229,161,0.03) 0%, transparent 35%);
      position: relative;
    }

    .hero-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 60px;
      align-items: center;
    }

    .hero-left h1 {
      font-size: 3rem;
      font-weight: 700;
      line-height: 1.2;
      color: var(--primary);
      margin-bottom: 24px;
      letter-spacing: -0.5px;
    }

    .hero-left .subtitle {
      font-size: 1.15rem;
      color: var(--text-secondary);
      margin-bottom: 32px;
      line-height: 1.6;
    }

    .data-strip {
      display: flex;
      gap: 40px;
      margin-bottom: 32px;
    }

    .data-item {
      font-family: var(--font-mono);
    }

    .data-number {
      font-size: 2.4rem;
      font-weight: 700;
      color: var(--accent);
      line-height: 1.2;
    }

    .data-label {
      color: var(--text-secondary);
      font-size: 0.9rem;
    }

    .hero-right img {
      width: 100%;
      border-radius: 20px;
      box-shadow: 0 20px 35px rgba(10,31,63,0.1);
    }

    /* 卡片网格 */
    .card-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
    }

    .advantage-card {
      background: var(--surface);
      padding: 32px;
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-sm);
      transition: all 0.3s ease;
      text-align: left;
    }

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

    .advantage-icon {
      font-size: 2.5rem;
      color: var(--accent);
      margin-bottom: 20px;
    }

    .advantage-card h3 {
      font-size: 1.25rem;
      margin-bottom: 12px;
      font-weight: 600;
    }

    /* 功能左右交替 */
    .feature-row {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 60px;
      align-items: center;
      margin-bottom: 80px;
    }

    .feature-row.reverse {
      direction: rtl;
    }
    .feature-row.reverse > * {
      direction: ltr;
    }

    .feature-img {
      width: 100%;
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-sm);
      background: #ddd;
    }

    /* 场景矩阵 */
    .scenario-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }

    .scenario-card {
      background: var(--surface);
      border: 1px solid var(--border);
      border-radius: var(--radius-card);
      padding: 24px;
      transition: border 0.2s;
    }

    .scenario-card:hover {
      border-color: var(--accent);
    }

    /* 案例数字 */
    .stats-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
      background: #F0F4FA;
      padding: 48px;
      border-radius: var(--radius-container);
    }

    .stat-item {
      text-align: center;
    }

    .stat-number {
      font-family: var(--font-mono);
      font-size: 3rem;
      font-weight: 700;
      color: var(--accent);
    }

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

    .faq-item {
      border-bottom: 1px solid var(--border);
      padding: 20px 0;
    }

    .faq-question {
      display: flex;
      justify-content: space-between;
      font-weight: 600;
      font-size: 1.1rem;
      cursor: pointer;
      background: none;
      border: none;
      width: 100%;
      text-align: left;
      color: var(--text);
    }

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

    .faq-item.active .faq-answer {
      max-height: 200px;
      padding-top: 12px;
    }

    /* CTA深色区 */
    .cta-section {
      background: var(--primary);
      color: white;
      border-radius: var(--radius-container);
      padding: 64px;
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 40px;
    }

    .cta-section h2 {
      color: white;
    }

    .contact-form input, .contact-form textarea {
      width: 100%;
      padding: 14px;
      margin-bottom: 16px;
      border-radius: var(--radius-btn);
      border: 1px solid #ccc;
      background: white;
    }

    .footer {
      background: var(--primary);
      color: #B0BEC5;
      padding: 60px 0 30px;
    }

    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 30px;
    }

    @media (max-width: 1024px) {
      .card-grid { grid-template-columns: repeat(2, 1fr); }
      .scenario-grid { grid-template-columns: repeat(2, 1fr); }
    }

    @media (max-width: 768px) {
      .desktop-nav { display: none; }
      .mobile-menu-btn { display: block; }
      .mobile-bottom-nav { display: flex; }
      .hero-grid, .feature-row, .cta-section { grid-template-columns: 1fr; }
      .card-grid, .stats-grid { grid-template-columns: 1fr; }
      .footer-grid { grid-template-columns: 1fr; }
      h1 { font-size: 2rem !important; }
      .data-strip { flex-wrap: wrap; }
    }