/* roulang page: index */
:root {
      --primary: #1A2B5F;
      --primary-hover: #15234A;
      --primary-light: #E8ECF9;
      --accent: #FF6B35;
      --accent-light: #FFF0E8;
      --bg: #F4F6FC;
      --surface: #FFFFFF;
      --text: #1E2330;
      --text-secondary: #7A8194;
      --text-on-primary: #FFFFFF;
      --success: #00B578;
      --warning: #FF9F0A;
      --error: #FA5151;
      --border-light: rgba(26,43,95,0.08);
      --shadow-sm: 0 4px 20px rgba(26,43,95,0.06);
      --shadow-md: 0 8px 30px rgba(26,43,95,0.12);
      --radius: 12px;
      --transition: 200ms ease-out;
      --container-max: 1200px;
      --font-hero: 48px;
      --font-h2: 32px;
      --font-h3: 20px;
      --font-body: 16px;
      --font-small: 14px;
    }

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

    body {
      font-family: 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', sans-serif;
      background-color: var(--bg);
      color: var(--text);
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
    }

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

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

    button, input, textarea {
      font-family: inherit;
    }

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

    /* 导航 */
    .site-header {
      position: sticky;
      top: 0;
      z-index: 50;
      background: rgba(255,255,255,0.92);
      backdrop-filter: blur(8px);
      box-shadow: 0 2px 12px rgba(26,43,95,0.04);
      transition: box-shadow var(--transition);
    }

    .header-inner {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 72px;
    }

    .logo {
      font-size: 24px;
      font-weight: 700;
      color: var(--primary);
      letter-spacing: 1px;
      display: flex;
      align-items: center;
      gap: 6px;
    }
    .logo span {
      background: linear-gradient(135deg, #1A2B5F 0%, #0F1A3A 100%);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
    }

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

    .nav-links a {
      font-size: var(--font-small);
      font-weight: 500;
      color: var(--text);
      position: relative;
      padding: 4px 0;
      transition: color var(--transition);
    }
    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--accent);
      transition: width var(--transition);
    }
    .nav-links a:hover {
      color: var(--accent);
    }
    .nav-links a:hover::after {
      width: 100%;
    }

    .menu-toggle {
      display: none;
      background: none;
      border: none;
      font-size: 28px;
      color: var(--primary);
      cursor: pointer;
    }

    /* 按钮系统 */
    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 12px 24px;
      border-radius: var(--radius);
      font-weight: 600;
      font-size: var(--font-small);
      transition: all var(--transition);
      cursor: pointer;
      border: 1px solid transparent;
      line-height: 1.2;
    }
    .btn-primary {
      background: var(--accent);
      color: white;
      border-color: var(--accent);
    }
    .btn-primary:hover {
      background: #E55A2B;
      transform: translateY(-1px);
      box-shadow: 0 8px 18px rgba(255,107,53,0.3);
    }
    .btn-secondary {
      background: transparent;
      border: 1px solid var(--primary);
      color: var(--primary);
    }
    .btn-secondary:hover {
      background: var(--primary-light);
      border-color: var(--primary-hover);
    }
    .btn-light {
      background: white;
      color: var(--primary);
      border: 1px solid white;
    }
    .btn-light:hover {
      background: #f0f2fa;
    }

    /* Hero */
    .hero {
      background: linear-gradient(135deg, #1A2B5F 0%, #0F1A3A 100%);
      padding: 80px 0;
      position: relative;
      overflow: hidden;
    }
    .hero::before {
      content: '';
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background-image: radial-gradient(circle at 30% 40%, rgba(255,255,255,0.05) 0%, transparent 30%);
      pointer-events: none;
    }
    .hero-grid {
      display: flex;
      align-items: center;
      gap: 48px;
      position: relative;
      z-index: 2;
    }
    .hero-content {
      flex: 1;
    }
    .hero h1 {
      font-size: var(--font-hero);
      font-weight: 700;
      line-height: 1.2;
      color: white;
      margin-bottom: 24px;
    }
    .hero h1 span {
      color: var(--accent);
    }
    .hero-sub {
      font-size: var(--font-body);
      color: rgba(255,255,255,0.8);
      margin-bottom: 40px;
      max-width: 480px;
    }
    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .hero-image {
      flex: 1;
      display: flex;
      justify-content: center;
    }
    .hero-image img {
      border-radius: var(--radius);
      box-shadow: 0 20px 40px rgba(0,0,0,0.2);
      max-height: 400px;
      object-fit: cover;
    }

    /* 通用板块 */
    .section {
      padding: 80px 0;
    }
    .section-title {
      text-align: center;
      margin-bottom: 48px;
    }
    .section-title h2 {
      font-size: var(--font-h2);
      font-weight: 700;
      color: var(--text);
      margin-bottom: 12px;
    }
    .section-title p {
      color: var(--text-secondary);
      font-size: var(--font-body);
    }

    /* 功能卡片网格 */
    .grid-3 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .feature-card {
      background: var(--surface);
      border-radius: var(--radius);
      padding: 32px 24px;
      box-shadow: var(--shadow-sm);
      transition: all var(--transition);
      text-align: center;
    }
    .feature-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-md);
    }
    .icon-wrap {
      width: 64px;
      height: 64px;
      background: var(--primary-light);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      margin: 0 auto 20px;
      transition: transform var(--transition);
    }
    .feature-card:hover .icon-wrap {
      transform: scale(1.1);
    }
    .feature-card h3 {
      font-size: var(--font-h3);
      margin-bottom: 12px;
    }
    .feature-card p {
      color: var(--text-secondary);
      font-size: var(--font-small);
    }

    /* 场景交替 */
    .scenario-row {
      display: flex;
      align-items: center;
      gap: 48px;
      margin-bottom: 64px;
    }
    .scenario-row.reverse {
      flex-direction: row-reverse;
    }
    .scenario-img {
      flex: 1;
      border-radius: var(--radius);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
    }
    .scenario-text {
      flex: 1;
    }
    .scenario-text h3 {
      font-size: 24px;
      margin-bottom: 16px;
    }
    .tag {
      display: inline-block;
      background: var(--accent-light);
      color: var(--accent);
      padding: 4px 12px;
      border-radius: 20px;
      font-size: 12px;
      font-weight: 600;
      margin-bottom: 12px;
    }

    /* 数据卡片 */
    .stats-grid {
      display: grid;
      grid-template-columns: repeat(4,1fr);
      gap: 24px;
    }
    .stat-card {
      background: var(--surface);
      border-radius: var(--radius);
      padding: 24px;
      text-align: center;
      box-shadow: var(--shadow-sm);
    }
    .stat-number {
      font-size: 36px;
      font-weight: 700;
      color: var(--accent);
    }

    /* 价格卡片 */
    .pricing-grid {
      display: grid;
      grid-template-columns: repeat(3,1fr);
      gap: 24px;
    }
    .price-card {
      background: var(--surface);
      border-radius: var(--radius);
      padding: 32px 24px;
      box-shadow: var(--shadow-sm);
      text-align: center;
      border: 1px solid transparent;
      transition: all var(--transition);
      position: relative;
    }
    .price-card.popular {
      border-color: var(--primary);
      box-shadow: var(--shadow-md);
    }
    .badge {
      background: var(--accent);
      color: white;
      font-size: 12px;
      padding: 4px 12px;
      border-radius: 20px;
      position: absolute;
      top: -12px;
      left: 50%;
      transform: translateX(-50%);
    }
    .price {
      font-size: 36px;
      font-weight: 700;
      color: var(--primary);
    }

    /* FAQ */
    .faq-item {
      background: var(--surface);
      border-radius: var(--radius);
      margin-bottom: 12px;
      box-shadow: var(--shadow-sm);
    }
    .faq-question {
      width: 100%;
      background: none;
      border: none;
      padding: 20px 24px;
      font-size: 18px;
      font-weight: 600;
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
    }
    .faq-answer {
      padding: 0 24px 20px;
      display: none;
      color: var(--text-secondary);
    }
    .faq-item.active .faq-answer {
      display: block;
    }

    /* 联系表单 */
    .contact-form {
      max-width: 480px;
      margin: 0 auto;
      background: var(--surface);
      padding: 32px;
      border-radius: var(--radius);
      box-shadow: var(--shadow-sm);
    }
    .form-input {
      width: 100%;
      padding: 12px 16px;
      border: 1px solid var(--border-light);
      border-radius: var(--radius);
      margin-bottom: 16px;
      transition: border var(--transition);
    }
    .form-input:focus {
      outline: none;
      border-color: var(--primary);
      box-shadow: 0 0 0 3px rgba(26,43,95,0.1);
    }

    /* 页脚 */
    .footer {
      background: #0F1A2A;
      color: rgba(255,255,255,0.7);
      padding: 48px 0 24px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 32px;
    }

    @media (max-width: 768px) {
      .container { padding: 0 16px; }
      .nav-links { display: none; }
      .menu-toggle { display: block; }
      .hero-grid { flex-direction: column; }
      .grid-3, .pricing-grid, .stats-grid { grid-template-columns: 1fr; }
      .scenario-row, .scenario-row.reverse { flex-direction: column; }
      .footer-grid { grid-template-columns: 1fr; }
      .hero h1 { font-size: 32px; }
    }