/* roulang page: index */
:root {
      --primary: #4E6EF2;
      --primary-hover: #3D5CE5;
      --primary-active: #2E4BD0;
      --accent: #FF5C72;
      --accent-hover: #E84D62;
      --green: #00B578;
      --orange: #FF9F0A;
      --bg: #F5F6FA;
      --white: #FFFFFF;
      --text: #1F2329;
      --text-secondary: #86909C;
      --border: #D1D5DB;
      --shadow-sm: 0 2px 8px rgba(0,0,0,0.04), 0 1px 2px rgba(0,0,0,0.02);
      --shadow-md: 0 8px 24px rgba(0,0,0,0.08), 0 2px 6px rgba(0,0,0,0.04);
      --radius-lg: 12px;
      --radius-md: 8px;
      --font-sans: 'Inter', 'PingFang SC', 'Microsoft YaHei', 'Hiragino Sans GB', system-ui, -apple-system, sans-serif;
      --transition: 200ms ease;
    }

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

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

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

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

    button, input {
      font-family: inherit;
      font-size: inherit;
      border: none;
      outline: none;
      background: none;
    }

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

    /* 导航 */
    .header {
      position: sticky;
      top: 0;
      z-index: 50;
      background: var(--white);
      border-bottom: 1px solid transparent;
      transition: box-shadow 0.3s ease, border-color 0.3s ease;
      padding: 0 16px;
    }

    .header.scrolled {
      box-shadow: var(--shadow-sm);
      border-bottom-color: rgba(0,0,0,0.04);
    }

    .nav {
      display: flex;
      align-items: center;
      justify-content: space-between;
      max-width: 1200px;
      margin: 0 auto;
      height: 64px;
    }

    .logo {
      font-size: 22px;
      font-weight: 700;
      letter-spacing: 0.5px;
      color: var(--text);
      white-space: nowrap;
    }
    .logo span {
      color: var(--primary);
    }

    .nav-links {
      display: flex;
      align-items: center;
      gap: 28px;
      font-size: 15px;
      font-weight: 500;
      color: var(--text);
    }

    .nav-links a {
      position: relative;
      padding: 4px 0;
      transition: color var(--transition);
    }

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

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

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

    .btn-nav {
      background: var(--primary);
      color: white;
      padding: 8px 20px;
      border-radius: var(--radius-md);
      font-weight: 600;
      font-size: 14px;
      transition: background var(--transition), transform var(--transition);
    }
    .btn-nav:hover {
      background: var(--primary-hover);
      transform: translateY(-1px);
    }

    .mobile-menu-btn {
      display: none;
      font-size: 24px;
      color: var(--text);
      background: transparent;
      cursor: pointer;
    }

    /* 移动端底部导航 */
    .mobile-bottom-nav {
      display: none;
      position: fixed;
      bottom: 0;
      left: 0;
      width: 100%;
      background: var(--white);
      box-shadow: 0 -2px 12px rgba(0,0,0,0.06);
      padding: 8px 16px;
      justify-content: space-around;
      align-items: center;
      z-index: 100;
      border-top-left-radius: 20px;
      border-top-right-radius: 20px;
    }
    .mobile-bottom-nav a {
      display: flex;
      flex-direction: column;
      align-items: center;
      font-size: 12px;
      color: var(--text-secondary);
      gap: 4px;
      font-weight: 500;
    }
    .mobile-bottom-nav a i {
      font-size: 18px;
    }
    .mobile-bottom-nav .cta-capsule {
      background: var(--accent);
      color: white;
      padding: 8px 20px;
      border-radius: 40px;
      font-weight: 600;
      font-size: 14px;
      box-shadow: 0 4px 12px rgba(255,92,114,0.3);
    }

    /* 通用板块 */
    section {
      padding: 80px 0;
    }

    .section-title {
      font-size: 28px;
      font-weight: 700;
      line-height: 1.3;
      margin-bottom: 16px;
      color: var(--text);
    }
    .section-sub {
      font-size: 16px;
      color: var(--text-secondary);
      margin-bottom: 48px;
    }

    /* 按钮系统 */
    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 12px 28px;
      border-radius: var(--radius-md);
      font-weight: 600;
      font-size: 15px;
      transition: all var(--transition);
      cursor: pointer;
    }
    .btn-primary {
      background: var(--primary);
      color: white;
      box-shadow: 0 2px 8px rgba(78,110,242,0.2);
    }
    .btn-primary:hover {
      background: var(--primary-hover);
      transform: translateY(-1px);
      box-shadow: 0 6px 18px rgba(78,110,242,0.3);
    }
    .btn-accent {
      background: var(--accent);
      color: white;
      box-shadow: 0 4px 12px rgba(255,92,114,0.25);
    }
    .btn-accent:hover {
      background: var(--accent-hover);
      transform: translateY(-1px);
      box-shadow: 0 8px 20px rgba(255,92,114,0.35);
    }
    .btn-outline {
      background: transparent;
      border: 1px solid var(--border);
      color: var(--text);
    }
    .btn-outline:hover {
      border-color: var(--primary);
      color: var(--primary);
      background: rgba(78,110,242,0.04);
    }

    /* Hero */
    .hero {
      background: var(--white);
      padding: 80px 0 100px;
    }
    .hero-grid {
      display: flex;
      align-items: center;
      gap: 60px;
    }
    .hero-content {
      flex: 1;
    }
    .hero h1 {
      font-size: 42px;
      font-weight: 700;
      line-height: 1.2;
      margin-bottom: 20px;
    }
    .hero-desc {
      font-size: 16px;
      color: var(--text-secondary);
      margin-bottom: 32px;
      max-width: 460px;
    }
    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
      margin-bottom: 28px;
    }
    .hero-visual {
      flex: 1;
      background: #f0f2fc;
      border-radius: 24px;
      overflow: hidden;
      position: relative;
      min-height: 320px;
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
    }
    .live-counter {
      display: flex;
      align-items: center;
      gap: 32px;
      background: #f8f9fd;
      padding: 16px 24px;
      border-radius: 100px;
      font-weight: 600;
    }
    .counter-num {
      font-size: 24px;
      color: var(--primary);
      font-weight: 700;
    }

    /* 指标看板 */
    .metrics {
      background: var(--bg);
    }
    .metrics-grid {
      display: grid;
      grid-template-columns: repeat(4,1fr);
      gap: 24px;
      margin-bottom: 32px;
    }
    .metric-card {
      background: var(--white);
      padding: 24px;
      border-radius: var(--radius-lg);
      box-shadow: var(--shadow-sm);
      text-align: center;
    }
    .metric-icon {
      font-size: 28px;
      color: var(--primary);
      margin-bottom: 12px;
    }
    .metric-value {
      font-size: 32px;
      font-weight: 700;
      color: var(--text);
    }
    .metric-label {
      font-size: 13px;
      color: var(--text-secondary);
      margin-top: 4px;
    }

    /* 服务矩阵 */
    .services-grid {
      display: grid;
      grid-template-columns: repeat(3,1fr);
      gap: 24px;
    }
    .service-card {
      background: var(--white);
      border-radius: var(--radius-lg);
      box-shadow: var(--shadow-sm);
      transition: box-shadow var(--transition), transform var(--transition);
      overflow: hidden;
    }
    .service-card:hover {
      box-shadow: var(--shadow-md);
      transform: translateY(-4px);
    }
    .service-img {
      height: 160px;
      background-size: cover;
      background-position: center;
    }
    .service-body {
      padding: 20px 24px 24px;
    }
    .service-body h3 {
      font-size: 20px;
      margin-bottom: 12px;
    }
    .service-link {
      margin-top: 16px;
      display: inline-flex;
      align-items: center;
      color: var(--primary);
      font-weight: 600;
    }

    /* 对比 */
    .compare-wrapper {
      display: flex;
      align-items: center;
      gap: 24px;
    }
    .compare-col {
      flex:1;
      background: var(--white);
      border-radius: var(--radius-lg);
      padding: 32px;
      box-shadow: var(--shadow-sm);
    }
    .vs-divider {
      font-weight: 700;
      font-size: 20px;
      color: var(--accent);
    }

    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }
    .faq-item {
      background: var(--white);
      border-radius: var(--radius-md);
      margin-bottom: 12px;
      box-shadow: var(--shadow-sm);
    }
    .faq-question {
      padding: 18px 24px;
      font-weight: 600;
      display: flex;
      justify-content: space-between;
      cursor: pointer;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      padding: 0 24px;
    }
    .faq-item.open .faq-answer {
      max-height: 200px;
      padding-bottom: 18px;
    }

    /* CTA */
    .cta-strip {
      background: rgba(78,110,242,0.04);
      display: flex;
      align-items: center;
      gap: 40px;
    }
    .cta-form input {
      background: white;
      border: 1px solid var(--border);
      padding: 12px 16px;
      border-radius: 40px;
      margin-right: 12px;
      width: 180px;
    }

    footer {
      background: #1F2329;
      color: #86909C;
      padding: 60px 0 30px;
    }

    @media (max-width: 1024px) {
      .metrics-grid { grid-template-columns: repeat(2,1fr); }
      .services-grid { grid-template-columns: repeat(2,1fr); }
    }
    @media (max-width: 640px) {
      .nav-links, .btn-nav { display: none; }
      .mobile-menu-btn { display: block; }
      .mobile-bottom-nav { display: flex; }
      .hero-grid { flex-direction: column; }
      .metrics-grid { grid-template-columns: 1fr; }
      .services-grid { grid-template-columns: 1fr; }
      .compare-wrapper { flex-direction: column; }
    }