/* roulang page: index */
:root {
      --primary: #0A6EFF;
      --primary-dark: #0856CC;
      --primary-light-bg: #EBF5FF;
      --accent: #FF6A3D;
      --accent-hover: #e85d32;
      --bg: #F8FAFC;
      --surface: #FFFFFF;
      --text-primary: #1E293B;
      --text-secondary: #64748B;
      --border: #E2E8F0;
      --radius-card: 16px;
      --radius-btn: 12px;
      --radius-tag: 20px;
      --shadow-sm: 0 4px 24px rgba(0,0,0,0.06);
      --shadow-hover: 0 12px 32px rgba(0,0,0,0.1);
      --transition: 0.3s ease;
      --max-width: 1200px;
      --nav-height: 72px;
      --font-h1: 2.75rem;
      --font-h2: 2rem;
      --font-h3: 1.25rem;
      --font-body: 1rem;
    }
    
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    
    html {
      scroll-behavior: smooth;
    }
    
    body {
      font-family: system-ui, -apple-system, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
      background-color: var(--bg);
      color: var(--text-primary);
      line-height: 1.7;
      -webkit-font-smoothing: antialiased;
    }
    
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    
    a {
      text-decoration: none;
      color: inherit;
    }
    
    button, input, textarea {
      font-family: inherit;
    }
    
    .container {
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 24px;
    }
    
    /* 导航 */
    #header {
      position: sticky;
      top: 0;
      width: 100%;
      height: var(--nav-height);
      background: rgba(255,255,255,0.96);
      backdrop-filter: blur(10px);
      box-shadow: 0 1px 0 var(--border);
      z-index: 100;
      display: flex;
      align-items: center;
      justify-content: center;
      padding: 0 16px;
    }
    
    .nav-container {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
      max-width: var(--max-width);
    }
    
    .logo {
      font-size: 1.8rem;
      font-weight: 700;
      color: var(--primary);
      display: flex;
      align-items: center;
      gap: 8px;
      letter-spacing: -0.5px;
    }
    .logo i {
      font-size: 2rem;
    }
    
    .nav-links {
      display: flex;
      align-items: center;
      gap: 2rem;
      font-weight: 500;
    }
    
    .nav-links a {
      color: var(--text-secondary);
      transition: color 0.2s;
      font-size: 0.95rem;
    }
    .nav-links a:hover {
      color: var(--primary);
    }
    
    .btn-primary {
      background: var(--primary);
      color: white;
      border: none;
      padding: 12px 28px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 1rem;
      cursor: pointer;
      transition: background 0.2s, transform 0.2s;
      display: inline-flex;
      align-items: center;
      gap: 6px;
    }
    .btn-primary:hover {
      background: var(--primary-dark);
      transform: scale(1.02);
    }
    
    .btn-outline {
      background: transparent;
      color: var(--primary);
      border: 2px solid var(--primary);
      padding: 12px 28px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 1rem;
      cursor: pointer;
      transition: all 0.2s;
      display: inline-flex;
      align-items: center;
      gap: 6px;
      background: white;
    }
    .btn-outline:hover {
      background: var(--primary-light-bg);
      border-color: var(--primary-dark);
    }
    
    .hamburger {
      display: none;
      font-size: 1.8rem;
      background: none;
      border: none;
      color: var(--text-primary);
      cursor: pointer;
    }
    
    .mobile-menu {
      display: none;
      position: fixed;
      top: var(--nav-height);
      left: 0;
      width: 100%;
      height: calc(100vh - var(--nav-height));
      background: white;
      flex-direction: column;
      align-items: center;
      justify-content: flex-start;
      gap: 2rem;
      padding-top: 4rem;
      z-index: 99;
    }
    
    .mobile-menu a {
      font-size: 1.5rem;
      color: var(--text-secondary);
      font-weight: 500;
    }
    .mobile-menu .btn-primary {
        margin-top: 1.5rem;
    }
    
    /* 区块通用 */
    section {
      padding: 100px 0;
    }
    
    @media (max-width: 768px) {
      section {
        padding: 60px 0;
      }
      .nav-links { display: none; }
      .hamburger { display: block; }
      .container { padding: 0 16px; }
      :root {
        --font-h1: 2rem;
        --font-h2: 1.6rem;
      }
    }
    
    /* Hero */
    #hero {
      background: var(--bg);
      position: relative;
      overflow: hidden;
    }
    .hero-wrapper {
      display: flex;
      align-items: center;
      gap: 3rem;
    }
    .hero-left {
      flex: 1;
    }
    .hero-left h1 {
      font-size: var(--font-h1);
      font-weight: 900;
      line-height: 1.2;
      letter-spacing: -0.02em;
      margin-bottom: 1.5rem;
      color: var(--text-primary);
    }
    .hero-left .subtitle {
      font-size: 1.2rem;
      color: var(--text-secondary);
      margin-bottom: 2.5rem;
    }
    .hero-buttons {
      display: flex;
      gap: 1rem;
      flex-wrap: wrap;
    }
    .hero-right {
      flex: 1;
      position: relative;
    }
    .hero-right img {
      width: 100%;
      border-radius: 24px;
      box-shadow: var(--shadow-hover);
      object-fit: cover;
    }
    .hero-blob {
      position: absolute;
      top: -40px;
      right: -40px;
      width: 400px;
      height: 400px;
      background: radial-gradient(circle, rgba(10,110,255,0.12) 0%, rgba(248,250,252,0) 70%);
      border-radius: 50%;
      z-index: 0;
    }
    @media (max-width: 768px) {
      .hero-wrapper {
        flex-direction: column;
        text-align: center;
      }
      .hero-buttons {
        justify-content: center;
      }
    }
    
    /* 指标 */
    .metrics-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 2rem;
    }
    .metric-card {
      background: var(--surface);
      padding: 2rem 1.5rem;
      border-radius: var(--radius-card);
      text-align: center;
      box-shadow: var(--shadow-sm);
      border-bottom: 4px solid var(--primary);
    }
    .metric-number {
      font-size: 3rem;
      font-weight: 800;
      color: var(--primary);
      line-height: 1.2;
    }
    .metric-label {
      color: var(--text-secondary);
      margin-top: 0.5rem;
    }
    @media (max-width: 768px) {
      .metrics-grid {
        grid-template-columns: 1fr 1fr;
      }
    }
    
    /* 服务卡片 */
    .services-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 2rem;
    }
    .service-card {
      background: var(--surface);
      padding: 2rem;
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
      display: flex;
      flex-direction: column;
    }
    .service-card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-hover);
    }
    .service-icon {
      font-size: 2.5rem;
      color: var(--primary);
      margin-bottom: 1.5rem;
    }
    .service-card h3 {
      font-size: var(--font-h3);
      margin-bottom: 0.8rem;
    }
    .service-desc {
      color: var(--text-secondary);
      margin-bottom: 1.2rem;
      flex: 1;
    }
    .tags {
      display: flex;
      flex-wrap: wrap;
      gap: 8px;
    }
    .tag {
      background: var(--primary-light-bg);
      color: var(--primary);
      padding: 4px 14px;
      border-radius: var(--radius-tag);
      font-size: 0.8rem;
      font-weight: 500;
    }
    @media (max-width: 768px) {
      .services-grid {
        grid-template-columns: 1fr;
      }
    }
    
    /* 对比 */
    #compare {
      background: white;
    }
    .compare-container {
      display: flex;
      align-items: stretch;
      gap: 2rem;
      position: relative;
    }
    .compare-col {
      flex: 1;
      background: #F1F5F9;
      border-radius: var(--radius-card);
      padding: 2rem;
    }
    .compare-col.right {
      background: white;
      border: 2px solid var(--primary);
      box-shadow: var(--shadow-sm);
    }
    .vs-badge {
      position: absolute;
      left: 50%;
      top: 20px;
      transform: translateX(-50%);
      background: var(--accent);
      color: white;
      width: 48px;
      height: 48px;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: bold;
      z-index: 2;
    }
    .compare-list {
      list-style: none;
      margin-top: 2rem;
    }
    .compare-list li {
      display: flex;
      align-items: center;
      gap: 12px;
      margin-bottom: 1rem;
      color: var(--text-secondary);
    }
    .right .compare-list li {
      color: var(--text-primary);
      font-weight: 500;
    }
    @media (max-width: 768px) {
      .compare-container {
        flex-direction: column;
        gap: 2rem;
      }
      .vs-badge {
        top: 45%;
        left: 50%;
        transform: translate(-50%, -50%);
      }
    }
    
    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }
    details {
      background: #F1F5F9;
      border-radius: 12px;
      margin-bottom: 1rem;
      padding: 0 1.5rem;
    }
    details[open] {
      border-left: 4px solid var(--primary);
      background: white;
      box-shadow: var(--shadow-sm);
    }
    summary {
      font-weight: 600;
      padding: 1.2rem 0;
      cursor: pointer;
      list-style: none;
      display: flex;
      justify-content: space-between;
      align-items: center;
    }
    summary i {
      transition: transform 0.2s;
    }
    details[open] summary i {
      transform: rotate(180deg);
      color: var(--primary);
    }
    .faq-content {
      padding-bottom: 1.5rem;
      color: var(--text-secondary);
    }
    
    /* CTA表单 */
    #cta {
      background: #F0F4FF;
      position: relative;
    }
    .cta-inner {
      max-width: 600px;
      margin: 0 auto;
      text-align: center;
    }
    .form-group {
      margin-bottom: 1.2rem;
      text-align: left;
    }
    input, textarea {
      width: 100%;
      padding: 14px;
      border: 1px solid var(--border);
      border-radius: 12px;
      font-size: 1rem;
      background: white;
      outline: none;
    }
    .trust-row {
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 1rem;
      margin-top: 1rem;
      color: var(--text-secondary);
      font-size: 0.9rem;
    }
    
    /* Footer */
    #footer {
      background: #1E293B;
      color: #CBD5E1;
      padding: 4rem 0 1.5rem;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 2rem;
      margin-bottom: 2rem;
    }
    .footer-col .logo {
      color: white;
    }
    .footer-col a {
      color: #94A3B8;
      display: block;
      margin-bottom: 8px;
      font-size: 0.95rem;
    }
    .copyright {
      text-align: center;
      font-size: 0.9rem;
      color: #64748B;
      padding-top: 2rem;
      border-top: 1px solid #334155;
    }
    @media (max-width: 768px) {
      .footer-grid {
        grid-template-columns: 1fr;
      }
    }
    
    h2.section-title {
      font-size: var(--font-h2);
      margin-bottom: 1rem;
      text-align: center;
    }
    .section-desc {
      text-align: center;
      color: var(--text-secondary);
      margin-bottom: 3rem;
    }