/* roulang page: index */
:root {
      --primary: #2E5BFF;
      --primary-deep: #1A3BB5;
      --primary-light: #EEF2FF;
      --green: #00C48C;
      --orange: #FF6B35;
      --text-dark: #1A1F36;
      --text-secondary: #6B7280;
      --text-muted: #9CA3AF;
      --bg-page: #F4F6FA;
      --bg-white: #FFFFFF;
      --border-light: #E5E7EB;
      --border-card: #F0F0F0;
      --shadow-card: 0 2px 12px rgba(0,0,0,0.04), 0 0 1px rgba(0,0,0,0.06);
      --shadow-card-hover: 0 8px 24px rgba(0,0,0,0.08);
      --radius-card: 16px;
      --radius-btn: 12px;
      --radius-full: 24px;
      --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      --transition: 0.2s ease;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    body {
      font-family: var(--font-sans);
      background-color: var(--bg-page);
      color: var(--text-dark);
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
    }
    img {
      max-width: 100%;
      display: block;
    }
    a {
      text-decoration: none;
      color: inherit;
      transition: var(--transition);
    }
    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
      width: 100%;
    }
    @media (max-width: 640px) {
      .container {
        padding: 0 16px;
      }
    }
    /* 导航 */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      background: rgba(255,255,255,0.96);
      backdrop-filter: blur(8px);
      height: 64px;
      display: flex;
      align-items: center;
      z-index: 100;
      box-shadow: 0 1px 4px rgba(0,0,0,0.04);
      border-bottom: 1px solid transparent;
    }
    .nav-bar {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
    }
    .logo {
      display: flex;
      align-items: center;
      gap: 8px;
      font-weight: 700;
      font-size: 20px;
      color: var(--text-dark);
      letter-spacing: -0.3px;
    }
    .logo svg {
      width: 28px;
      height: 28px;
      stroke: var(--primary);
      stroke-width: 2;
      fill: none;
    }
    .nav-menu {
      display: flex;
      align-items: center;
      gap: 32px;
      list-style: none;
    }
    .nav-menu a {
      font-size: 14px;
      font-weight: 500;
      color: #4B5563;
      padding: 4px 0;
      position: relative;
    }
    .nav-menu a:hover,
    .nav-menu a.active {
      color: var(--primary);
    }
    .nav-menu a::after {
      content: '';
      position: absolute;
      bottom: -2px;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--primary);
      transition: width 0.2s ease;
    }
    .nav-menu a:hover::after,
    .nav-menu a.active::after {
      width: 100%;
    }
    .hamburger {
      display: none;
      background: none;
      border: none;
      cursor: pointer;
      flex-direction: column;
      gap: 5px;
      z-index: 110;
    }
    .hamburger span {
      width: 24px;
      height: 2px;
      background: var(--text-dark);
      border-radius: 2px;
      transition: 0.2s;
    }
    @media (max-width: 1024px) {
      .nav-menu {
        position: fixed;
        top: 0;
        right: -100%;
        width: 80%;
        max-width: 320px;
        height: 100vh;
        background: white;
        flex-direction: column;
        align-items: flex-start;
        padding: 96px 32px 32px;
        gap: 40px;
        box-shadow: -4px 0 20px rgba(0,0,0,0.06);
        transition: right 0.25s ease;
      }
      .nav-menu.active {
        right: 0;
      }
      .nav-menu a {
        font-size: 18px;
        color: var(--text-dark);
      }
      .hamburger {
        display: flex;
      }
    }
    /* 首屏 Hero */
    .hero {
      padding: 120px 0 80px;
      background-color: var(--bg-page);
      position: relative;
      overflow: hidden;
    }
    .hero .container {
      display: flex;
      align-items: center;
      gap: 48px;
      flex-wrap: wrap;
    }
    .hero-content {
      flex: 1 1 400px;
    }
    .hero-content h1 {
      font-size: 48px;
      font-weight: 700;
      line-height: 1.2;
      color: var(--text-dark);
      margin-bottom: 16px;
      letter-spacing: -0.5px;
    }
    .hero-content p {
      font-size: 18px;
      color: var(--text-secondary);
      margin-bottom: 32px;
      max-width: 500px;
      line-height: 1.6;
    }
    .btn-group {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 16px;
      transition: all 0.25s ease;
      border: 2px solid transparent;
      cursor: pointer;
    }
    .btn-primary {
      background: var(--primary);
      color: white;
      border-color: var(--primary);
    }
    .btn-primary:hover {
      background: var(--primary-deep);
      border-color: var(--primary-deep);
      transform: translateY(-1px);
      box-shadow: 0 8px 16px rgba(46,91,255,0.25);
    }
    .btn-outline {
      background: transparent;
      color: var(--primary);
      border-color: var(--primary);
    }
    .btn-outline:hover {
      background: var(--primary-light);
      border-color: var(--primary);
    }
    .hero-image {
      flex: 1 1 400px;
      position: relative;
    }
    .hero-image img {
      width: 100%;
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-card);
      object-fit: cover;
      aspect-ratio: 4/3;
    }
    .hero-image::before {
      content: '';
      position: absolute;
      top: -10px;
      left: -10px;
      width: 100%;
      height: 100%;
      background: radial-gradient(circle at 30% 30%, rgba(46,91,255,0.1) 0%, transparent 60%);
      border-radius: var(--radius-card);
      z-index: -1;
    }
    @media (max-width: 768px) {
      .hero {
        padding: 100px 0 60px;
      }
      .hero-content h1 {
        font-size: 36px;
      }
      .hero-content p {
        font-size: 16px;
      }
    }
    /* 通用区块 */
    section {
      padding: 80px 0;
    }
    .section-title {
      text-align: center;
      margin-bottom: 48px;
    }
    .section-title h2 {
      font-size: 36px;
      font-weight: 600;
      color: var(--text-dark);
      margin-bottom: 12px;
      letter-spacing: -0.3px;
    }
    .section-title p {
      font-size: 16px;
      color: var(--text-secondary);
      max-width: 600px;
      margin: 0 auto;
    }
    /* 卡片网格 */
    .grid-3 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .grid-2 {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 24px;
    }
    @media (max-width: 768px) {
      .grid-3, .grid-2 {
        grid-template-columns: 1fr;
      }
      section {
        padding: 60px 0;
      }
      .section-title h2 {
        font-size: 28px;
      }
    }
    .card {
      background: var(--bg-white);
      border-radius: var(--radius-card);
      padding: 32px;
      box-shadow: var(--shadow-card);
      transition: box-shadow 0.25s, transform 0.2s;
    }
    .card:hover {
      box-shadow: var(--shadow-card-hover);
      transform: translateY(-4px);
    }
    .icon-circle {
      width: 48px;
      height: 48px;
      background: rgba(46,91,255,0.08);
      border-radius: 12px;
      display: flex;
      align-items: center;
      justify-content: center;
      margin-bottom: 16px;
      color: var(--primary);
    }
    .card h3 {
      font-size: 20px;
      font-weight: 600;
      margin-bottom: 8px;
    }
    .card p {
      font-size: 15px;
      color: var(--text-secondary);
      line-height: 1.6;
    }
    /* 数据区 */
    .stats {
      background: linear-gradient(135deg, #2E5BFF 0%, #1A3BB5 100%);
      color: white;
      padding: 64px 0;
      border-radius: 0;
    }
    .stats-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      text-align: center;
      gap: 24px;
    }
    .stat-number {
      font-size: 40px;
      font-weight: 700;
      margin-bottom: 8px;
    }
    .stat-label {
      font-size: 14px;
      opacity: 0.85;
    }
    @media (max-width: 640px) {
      .stats-grid {
        grid-template-columns: 1fr 1fr;
      }
    }
    /* 服务卡片混合高度 */
    .service-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .service-card {
      background: white;
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-card);
      transition: all 0.25s;
      overflow: hidden;
    }
    .service-card:hover {
      box-shadow: var(--shadow-card-hover);
    }
    .service-img {
      height: 180px;
      background-size: cover;
      background-position: center;
    }
    .service-body {
      padding: 24px;
    }
    .service-body h3 {
      font-size: 20px;
      font-weight: 600;
      margin-bottom: 8px;
    }
    .tag {
      display: inline-block;
      background: rgba(255,107,53,0.1);
      color: var(--orange);
      font-size: 12px;
      font-weight: 600;
      padding: 4px 10px;
      border-radius: 20px;
      margin-bottom: 12px;
    }
    @media (max-width: 1024px) {
      .service-grid {
        grid-template-columns: repeat(2, 1fr);
      }
    }
    @media (max-width: 640px) {
      .service-grid {
        grid-template-columns: 1fr;
      }
    }
    /* 流程 */
    .process-steps {
      display: flex;
      justify-content: space-between;
      align-items: flex-start;
      text-align: center;
      position: relative;
    }
    .step-item {
      flex: 1;
      display: flex;
      flex-direction: column;
      align-items: center;
    }
    .step-circle {
      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: 18px;
      margin-bottom: 12px;
      z-index: 2;
    }
    .step-line {
      position: absolute;
      top: 24px;
      left: 15%;
      width: 70%;
      height: 1px;
      border-top: 2px dashed var(--border-light);
      z-index: 1;
    }
    @media (max-width: 768px) {
      .process-steps {
        flex-direction: column;
        gap: 32px;
      }
      .step-line {
        display: none;
      }
    }
    /* FAQ */
    .faq-item {
      background: white;
      border-radius: var(--radius-card);
      padding: 20px 24px;
      margin-bottom: 12px;
      box-shadow: var(--shadow-card);
      cursor: pointer;
      transition: 0.2s;
      border: 1px solid transparent;
    }
    .faq-item:hover {
      border-color: var(--primary-light);
    }
    .faq-question {
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-weight: 600;
      font-size: 16px;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      color: var(--text-secondary);
      font-size: 15px;
      margin-top: 0;
      line-height: 1.6;
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      margin-top: 12px;
    }
    .faq-icon {
      font-size: 20px;
      color: var(--primary);
    }
    /* CTA */
    .cta-block {
      background: linear-gradient(135deg, #2E5BFF 0%, #1A3BB5 100%);
      border-radius: var(--radius-card);
      padding: 64px 32px;
      text-align: center;
      color: white;
    }
    .cta-block h2 {
      font-size: 32px;
      font-weight: 700;
      margin-bottom: 16px;
    }
    .btn-white {
      background: white;
      color: var(--primary);
      border: none;
    }
    .btn-white:hover {
      background: #f0f4ff;
    }
    /* 页脚 */
    .footer {
      background: #1A1F36;
      color: #9CA3AF;
      padding: 48px 0 24px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 32px;
      margin-bottom: 40px;
    }
    .footer-logo {
      font-weight: 700;
      font-size: 18px;
      color: white;
    }
    .footer a {
      color: #9CA3AF;
      font-size: 14px;
    }
    .footer a:hover {
      color: white;
    }
    .copyright {
      text-align: center;
      font-size: 14px;
      border-top: 1px solid rgba(255,255,255,0.08);
      padding-top: 24px;
    }
    @media (max-width: 768px) {
      .footer-grid {
        grid-template-columns: 1fr 1fr;
      }
    }
    @media (max-width: 480px) {
      .footer-grid {
        grid-template-columns: 1fr;
      }
    }