/* roulang page: index */
:root {
      --primary: #6C3CEC;
      --primary-dark: #5A2ECC;
      --accent: #00E5A0;
      --bg: #F8F9FC;
      --card-bg: #FFFFFF;
      --dark-bg: #1E1534;
      --text-main: #2D3748;
      --text-secondary: #718096;
      --border-light: #E2E8F0;
      --radius-card: 12px;
      --radius-btn: 8px;
      --shadow-card: 0 1px 3px rgba(0,0,0,0.04), 0 6px 16px rgba(0,0,0,0.06);
      --shadow-hover: 0 4px 12px rgba(0,0,0,0.08), 0 12px 28px rgba(0,0,0,0.1);
      --transition: 0.25s ease;
      --font-sans: 'Inter', 'Noto Sans SC', system-ui, -apple-system, sans-serif;
      --container-width: 1200px;
    }
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }
    html {
      scroll-behavior: smooth;
    }
    body {
      font-family: var(--font-sans);
      background-color: var(--bg);
      color: var(--text-main);
      line-height: 1.5;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    a {
      text-decoration: none;
      color: inherit;
      transition: var(--transition);
    }
    .container {
      max-width: var(--container-width);
      margin: 0 auto;
      padding: 0 20px;
    }
    /* 导航 */
    #nav {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      background: white;
      border-bottom: 1px solid var(--border-light);
      z-index: 50;
      padding: 0 20px;
      box-shadow: 0 2px 10px rgba(0,0,0,0.02);
    }
    .nav-inner {
      display: flex;
      align-items: center;
      justify-content: space-between;
      max-width: var(--container-width);
      margin: 0 auto;
      height: 70px;
    }
    .logo {
      font-weight: 700;
      font-size: 24px;
      color: var(--primary);
      display: flex;
      align-items: center;
      gap: 10px;
      letter-spacing: -0.3px;
    }
    .logo i {
      font-size: 28px;
      color: var(--accent);
    }
    .nav-links {
      display: flex;
      align-items: center;
      gap: 28px;
    }
    .nav-links a {
      font-weight: 500;
      font-size: 16px;
      color: var(--text-secondary);
      position: relative;
    }
    .nav-links a:hover,
    .nav-links a.active {
      color: var(--primary);
    }
    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: -6px;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--primary);
      transition: width 0.2s ease;
    }
    .nav-links a:hover::after {
      width: 100%;
    }
    .nav-cta {
      background: var(--primary);
      color: white;
      padding: 10px 24px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 16px;
      transition: var(--transition);
      border: none;
      cursor: pointer;
      white-space: nowrap;
    }
    .nav-cta:hover {
      background: var(--primary-dark);
      transform: scale(1.02);
      box-shadow: 0 0 0 3px rgba(0,229,160,0.3);
      color: white;
    }
    .hamburger {
      display: none;
      font-size: 24px;
      color: var(--text-main);
      background: none;
      border: none;
      cursor: pointer;
    }
    @media (max-width: 768px) {
      .nav-links {
        display: none;
        position: absolute;
        top: 70px;
        left: 0;
        width: 100%;
        background: white;
        flex-direction: column;
        padding: 20px;
        gap: 20px;
        box-shadow: 0 10px 20px rgba(0,0,0,0.05);
        border-bottom: 1px solid var(--border-light);
      }
      .nav-links.active {
        display: flex;
      }
      .hamburger {
        display: block;
      }
      .nav-cta.desktop {
        display: none;
      }
      .nav-actions {
        display: flex;
        align-items: center;
        gap: 15px;
      }
      .mobile-cta {
        display: inline-block;
        background: var(--primary);
        color: white;
        padding: 8px 18px;
        border-radius: var(--radius-btn);
        font-weight: 600;
      }
    }
    @media (min-width: 769px) {
      .mobile-cta {
        display: none;
      }
    }
    /* 板块间距 */
    section {
      padding: 100px 0;
    }
    @media (max-width: 768px) {
      section {
        padding: 60px 0;
      }
    }
    /* 按钮系统 */
    .btn-primary {
      background: var(--primary);
      color: white;
      border: none;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 16px;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      transition: var(--transition);
      cursor: pointer;
      border: 2px solid transparent;
    }
    .btn-primary:hover {
      background: var(--primary-dark);
      transform: scale(1.02);
      box-shadow: 0 0 0 3px rgba(0,229,160,0.3);
      color: white;
    }
    .btn-outline {
      background: transparent;
      color: var(--accent);
      border: 2px solid var(--accent);
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      display: inline-flex;
      align-items: center;
      gap: 6px;
      transition: var(--transition);
    }
    .btn-outline:hover {
      background: var(--accent);
      color: white;
    }
    /* Hero */
    #hero {
      background: var(--bg);
      padding-top: 120px;
    }
    .hero-grid {
      display: flex;
      align-items: center;
      gap: 50px;
    }
    .hero-text {
      flex: 1;
    }
    .hero-text h1 {
      font-size: 48px;
      line-height: 1.2;
      font-weight: 700;
      letter-spacing: -0.5px;
      color: var(--text-main);
      margin-bottom: 20px;
    }
    .hero-text .subtitle {
      font-size: 18px;
      color: var(--text-secondary);
      margin-bottom: 30px;
      max-width: 500px;
    }
    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .hero-image {
      flex: 1;
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-card);
    }
    .hero-image img {
      width: 100%;
      height: auto;
      object-fit: cover;
    }
    @media (max-width: 768px) {
      .hero-grid {
        flex-direction: column;
        text-align: center;
      }
      .hero-text h1 {
        font-size: 32px;
      }
      .hero-buttons {
        justify-content: center;
      }
    }
    /* 标题装饰 */
    .section-title {
      font-size: 36px;
      font-weight: 700;
      margin-bottom: 16px;
      text-align: center;
      color: var(--text-main);
    }
    .section-subtitle {
      color: var(--text-secondary);
      text-align: center;
      max-width: 680px;
      margin: 0 auto 50px;
      font-size: 18px;
    }
    /* 卡片网格 */
    .card-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 32px;
    }
    .card {
      background: var(--card-bg);
      border-radius: var(--radius-card);
      padding: 32px;
      box-shadow: var(--shadow-card);
      transition: var(--transition);
    }
    .card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
    }
    .icon-circle {
      width: 64px;
      height: 64px;
      background: rgba(0,229,160,0.15);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      margin-bottom: 20px;
      color: var(--accent);
      font-size: 28px;
    }
    .card h3 {
      font-size: 22px;
      font-weight: 600;
      margin-bottom: 12px;
    }
    .card p {
      color: var(--text-secondary);
    }
    @media (max-width: 1024px) {
      .card-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .section-title {
        font-size: 28px;
      }
    }
    @media (max-width: 768px) {
      .card-grid {
        grid-template-columns: 1fr;
      }
      .section-title {
        font-size: 24px;
      }
    }
    /* 服务卡片大图 */
    .service-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 32px;
    }
    .service-card {
      background: var(--card-bg);
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-card);
      transition: var(--transition);
    }
    .service-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
    }
    .service-img {
      height: 200px;
      background-size: cover;
      background-position: center;
    }
    .service-content {
      padding: 28px;
    }
    .service-content h3 {
      font-size: 22px;
      margin-bottom: 10px;
    }
    @media (max-width: 1024px) {
      .service-grid {
        grid-template-columns: repeat(2, 1fr);
      }
    }
    @media (max-width: 768px) {
      .service-grid {
        grid-template-columns: 1fr;
      }
    }
    /* 数据深色块 */
    .stats-bg {
      background: var(--dark-bg);
      border-radius: var(--radius-card);
      padding: 60px 40px;
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 30px;
      text-align: center;
    }
    .stat-item .stat-number {
      font-size: 40px;
      font-weight: 700;
      color: var(--accent);
    }
    .stat-label {
      color: rgba(255,255,255,0.8);
      margin-top: 8px;
    }
    @media (max-width: 768px) {
      .stats-bg {
        grid-template-columns: repeat(2, 1fr);
      }
    }
    /* 案例卡片 */
    .case-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 32px;
    }
    .case-card {
      background: var(--card-bg);
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-card);
    }
    .case-img {
      height: 180px;
      background-size: cover;
    }
    .case-info {
      padding: 24px;
    }
    .tag {
      display: inline-block;
      border: 1px solid var(--accent);
      color: var(--accent);
      padding: 4px 12px;
      border-radius: 20px;
      font-size: 14px;
      margin-bottom: 12px;
    }
    @media (max-width: 1024px) {
      .case-grid {
        grid-template-columns: repeat(2, 1fr);
      }
    }
    @media (max-width: 768px) {
      .case-grid {
        grid-template-columns: 1fr;
      }
    }
    /* 流程 */
    .process-steps {
      display: flex;
      justify-content: space-between;
      align-items: flex-start;
      position: relative;
    }
    .step {
      text-align: center;
      flex: 1;
      position: relative;
    }
    .step-num {
      width: 48px;
      height: 48px;
      background: var(--primary);
      color: white;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 700;
      font-size: 20px;
      margin: 0 auto 15px;
    }
    .step h4 {
      font-weight: 600;
      margin-bottom: 8px;
    }
    .step p {
      color: var(--text-secondary);
      font-size: 15px;
    }
    .process-line {
      position: absolute;
      top: 24px;
      left: 20%;
      width: 60%;
      height: 2px;
      background: repeating-linear-gradient(to right, var(--border-light) 0px, var(--border-light) 6px, transparent 6px, transparent 12px);
      z-index: -1;
    }
    @media (max-width: 768px) {
      .process-steps {
        flex-direction: column;
        gap: 32px;
        align-items: center;
      }
      .process-line {
        display: none;
      }
    }
    /* FAQ */
    .faq-item {
      background: var(--card-bg);
      border-radius: var(--radius-card);
      margin-bottom: 16px;
      box-shadow: var(--shadow-card);
      overflow: hidden;
    }
    .faq-question {
      padding: 24px 32px;
      font-weight: 600;
      font-size: 18px;
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
      background: white;
      border: none;
      width: 100%;
      text-align: left;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      background: #f9fafc;
      padding: 0 32px;
    }
    .faq-answer p {
      padding: 20px 0;
      color: var(--text-secondary);
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
    }
    .faq-icon {
      color: var(--accent);
      transition: transform 0.2s;
    }
    .faq-item.active .faq-icon {
      transform: rotate(180deg);
    }
    /* CTA 深色 */
    .cta-dark {
      background: var(--dark-bg);
      border-radius: var(--radius-card);
      padding: 80px 40px;
      text-align: center;
    }
    .cta-dark h2 {
      color: white;
      font-size: 36px;
      margin-bottom: 20px;
    }
    .cta-dark p {
      color: #cbd5e0;
      font-size: 18px;
      margin-bottom: 32px;
    }
    .cta-buttons {
      display: flex;
      gap: 20px;
      justify-content: center;
      flex-wrap: wrap;
    }
    /* 页脚 */
    footer {
      background: #F1F3F6;
      padding: 60px 0 30px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
      margin-bottom: 40px;
    }
    .footer-brand p {
      color: var(--text-secondary);
      margin-top: 15px;
    }
    .footer-links h4 {
      margin-bottom: 16px;
    }
    .footer-links a {
      display: block;
      color: var(--text-secondary);
      margin-bottom: 10px;
    }
    .copyright {
      text-align: center;
      color: var(--text-secondary);
      border-top: 1px solid var(--border-light);
      padding-top: 25px;
    }
    @media (max-width: 768px) {
      .footer-grid {
        grid-template-columns: 1fr;
      }
    }
    .decor-bg {
      position: relative;
    }
    .decor-bg::before {
      content: "";
      position: absolute;
      top: 0;
      right: 0;
      width: 300px;
      height: 300px;
      background: radial-gradient(circle, rgba(108,60,236,0.04) 0%, transparent 70%);
      z-index: 0;
    }