/* roulang page: index */
:root {
      --primary-deep: #1B1C3E;
      --primary-highlight: #5D5FEF;
      --primary-hover: #4B4DD1;
      --functional-green: #00B578;
      --alert-orange: #FF9F0A;
      --error-red: #FA5151;
      --bg-light: #F5F6FA;
      --card-bg: #FFFFFF;
      --text-main: #1F2329;
      --text-secondary: #86909C;
      --text-on-dark: #E8E8EF;
      --border-light: #E5E8EF;
      --shadow-sm: 0 4px 12px rgba(0,0,0,0.04), 0 1px 2px rgba(0,0,0,0.02);
      --shadow-hover: 0 8px 24px rgba(0,0,0,0.08);
      --radius-card: 12px;
      --radius-btn: 8px;
      --font-stack: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Microsoft YaHei", sans-serif;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    body {
      font-family: var(--font-stack);
      background-color: var(--bg-light);
      color: var(--text-main);
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
    }
    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
    }
    a {
      text-decoration: none;
      color: inherit;
      transition: color 0.2s ease;
    }
    img {
      max-width: 100%;
      display: block;
      height: auto;
    }
    button, .btn {
      cursor: pointer;
      font-family: var(--font-stack);
      border: none;
      outline: none;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      transition: all 0.25s ease;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 15px;
    }
    h1, h2, h3 {
      font-weight: 600;
      line-height: 1.4;
    }

    /* 导航栏 */
    .navbar {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 1000;
      background: transparent;
      transition: background 0.3s ease, backdrop-filter 0.3s ease, box-shadow 0.3s ease;
      padding: 16px 0;
    }
    .navbar.scrolled {
      background: rgba(255,255,255,0.85);
      backdrop-filter: blur(12px);
      box-shadow: 0 1px 4px rgba(0,0,0,0.04);
      border-bottom: 1px solid var(--border-light);
    }
    .navbar .container {
      display: flex;
      align-items: center;
      justify-content: space-between;
    }
    .logo {
      font-size: 20px;
      font-weight: 700;
      color: #fff;
      transition: color 0.3s ease;
      display: flex;
      align-items: center;
      gap: 8px;
    }
    .navbar.scrolled .logo {
      color: var(--primary-deep);
    }
    .logo-icon {
      width: 28px;
      height: 28px;
      border: 2px solid currentColor;
      border-radius: 50%;
      position: relative;
    }
    .logo-icon::after {
      content: "";
      position: absolute;
      top: 4px;
      left: 4px;
      width: 16px;
      height: 16px;
      border: 2px solid currentColor;
      border-radius: 50%;
      opacity: 0.6;
    }
    .nav-menu {
      display: flex;
      align-items: center;
      gap: 32px;
    }
    .nav-link {
      font-size: 14px;
      font-weight: 500;
      color: rgba(255,255,255,0.9);
      transition: color 0.2s;
      position: relative;
      padding-bottom: 4px;
    }
    .navbar.scrolled .nav-link {
      color: var(--text-main);
    }
    .nav-link:hover, .nav-link.active {
      color: var(--primary-highlight);
    }
    .nav-link.active::after {
      content: "";
      position: absolute;
      bottom: 0;
      left: 0;
      width: 100%;
      height: 2px;
      background: var(--primary-highlight);
      border-radius: 2px;
    }
    .btn-primary {
      background: var(--primary-highlight);
      color: #fff;
      padding: 10px 24px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 14px;
    }
    .btn-primary:hover {
      background: var(--primary-hover);
      box-shadow: 0 4px 12px rgba(93,95,239,0.4);
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
    }
    .hamburger span {
      width: 24px;
      height: 2px;
      background: #fff;
      transition: 0.3s;
    }
    .navbar.scrolled .hamburger span {
      background: var(--primary-deep);
    }

    /* Hero */
    .hero {
      background: var(--primary-deep);
      min-height: 100vh;
      display: flex;
      align-items: center;
      position: relative;
      overflow: hidden;
      padding: 120px 0 80px;
    }
    .stars-canvas {
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      pointer-events: none;
    }
    .hero .container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 40px;
      position: relative;
      z-index: 2;
    }
    .hero-text {
      flex: 1;
      max-width: 560px;
    }
    .hero h1 {
      font-size: 36px;
      font-weight: 700;
      color: #fff;
      line-height: 1.3;
      margin-bottom: 16px;
    }
    .hero-sub {
      color: #B0B3D1;
      font-size: 16px;
      margin-bottom: 32px;
      max-width: 480px;
    }
    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .btn-ghost {
      background: transparent;
      border: 1px solid rgba(255,255,255,0.5);
      color: #fff;
      padding: 10px 24px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 14px;
    }
    .btn-ghost:hover {
      background: rgba(255,255,255,0.1);
    }
    .hero-visual {
      flex: 1;
      display: flex;
      justify-content: center;
      align-items: center;
    }
    .orbit {
      width: 280px;
      height: 280px;
      border: 2px solid rgba(93,95,239,0.4);
      border-radius: 50%;
      position: relative;
      animation: spin 20s linear infinite;
    }
    .orbit::before {
      content: "";
      position: absolute;
      top: -10px;
      left: 50%;
      width: 20px;
      height: 20px;
      background: var(--primary-highlight);
      border-radius: 50%;
      box-shadow: 0 0 20px var(--primary-highlight);
      transform: translateX(-50%);
    }
    @keyframes spin {
      from { transform: rotate(0deg); }
      to { transform: rotate(360deg); }
    }

    /* 通用板块 */
    section {
      padding: 80px 0;
    }
    .section-title {
      font-size: 26px;
      font-weight: 600;
      color: var(--primary-deep);
      text-align: center;
      margin-bottom: 16px;
    }
    .section-desc {
      text-align: center;
      color: var(--text-secondary);
      max-width: 640px;
      margin: 0 auto 48px;
    }

    /* 优势卡片 */
    .features-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .feature-card {
      background: var(--card-bg);
      border-radius: var(--radius-card);
      padding: 32px 24px;
      box-shadow: var(--shadow-sm);
      transition: all 0.25s ease;
      text-align: center;
    }
    .feature-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
    }
    .feature-icon {
      width: 56px;
      height: 56px;
      background: rgba(93,95,239,0.08);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      margin: 0 auto 16px;
      color: var(--primary-highlight);
      font-size: 24px;
    }
    .feature-card h3 {
      font-size: 18px;
      margin-bottom: 8px;
    }
    .feature-card p {
      color: var(--text-secondary);
      font-size: 14px;
    }

    /* 产品服务 */
    .service-row {
      display: flex;
      align-items: center;
      gap: 48px;
      margin-bottom: 64px;
    }
    .service-row.reverse {
      flex-direction: row-reverse;
    }
    .service-img {
      flex: 1;
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
      border: 1px solid var(--border-light);
    }
    .service-img img {
      width: 100%;
      object-fit: cover;
    }
    .service-text {
      flex: 1;
    }
    .service-text h2 {
      font-size: 24px;
      color: var(--primary-deep);
      margin-bottom: 12px;
    }
    .service-text p {
      color: var(--text-secondary);
      margin-bottom: 16px;
    }
    .text-link {
      color: var(--primary-highlight);
      font-weight: 500;
      display: inline-flex;
      align-items: center;
      gap: 4px;
    }
    .text-link:hover {
      text-decoration: underline;
    }

    /* 数据 */
    .data-section {
      background: #EEF0F8;
    }
    .stats-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
      text-align: center;
    }
    .stat-number {
      font-size: 36px;
      font-weight: 700;
      color: var(--primary-deep);
    }
    .stat-label {
      color: var(--text-secondary);
      font-size: 13px;
    }

    /* 解决方案 */
    .solutions-grid {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 24px;
    }
    .solution-card {
      background: var(--card-bg);
      border-radius: var(--radius-card);
      padding: 32px;
      box-shadow: var(--shadow-sm);
      border: 1px solid transparent;
      transition: 0.25s;
    }
    .solution-card:hover {
      border-color: var(--primary-highlight);
      transform: translateY(-4px);
    }
    .solution-icon {
      font-size: 32px;
      color: var(--primary-highlight);
      margin-bottom: 16px;
    }

    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }
    .faq-item {
      border-bottom: 1px solid var(--border-light);
    }
    .faq-question {
      display: flex;
      justify-content: space-between;
      align-items: center;
      padding: 16px 0;
      cursor: pointer;
      font-weight: 500;
      font-size: 16px;
    }
    .faq-icon {
      font-size: 24px;
      color: var(--primary-highlight);
      transition: transform 0.25s;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      color: var(--text-secondary);
      font-size: 14px;
    }
    .faq-item.active .faq-answer {
      max-height: 150px;
      padding-bottom: 16px;
    }
    .faq-item.active .faq-icon {
      transform: rotate(45deg);
    }

    /* CTA */
    .cta-banner {
      background: var(--primary-deep);
      text-align: center;
      padding: 80px 24px;
    }
    .cta-banner h2 {
      color: #fff;
      font-size: 28px;
      margin-bottom: 12px;
    }
    .cta-banner p {
      color: #B0B3D1;
      margin-bottom: 24px;
    }

    /* Footer */
    .footer {
      background: #1F2329;
      color: #E8E8EF;
      padding: 48px 0 24px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 32px;
      margin-bottom: 32px;
    }
    .footer-brand p {
      color: var(--text-secondary);
      font-size: 13px;
      margin-top: 8px;
    }
    .footer h4 {
      margin-bottom: 12px;
      font-size: 16px;
    }
    .footer ul {
      list-style: none;
    }
    .footer li {
      margin-bottom: 8px;
      font-size: 14px;
    }
    .footer a:hover {
      color: var(--primary-highlight);
    }
    .copyright {
      text-align: center;
      font-size: 12px;
      color: #5A5D66;
      border-top: 1px solid #2E3239;
      padding-top: 16px;
    }

    @media (max-width: 1024px) {
      .hero .container { flex-direction: column; text-align: center; }
      .hero-text { max-width: 100%; }
      .features-grid { grid-template-columns: 1fr 1fr; }
    }
    @media (max-width: 768px) {
      .nav-menu { display: none; }
      .hamburger { display: flex; }
      .features-grid, .stats-grid, .solutions-grid { grid-template-columns: 1fr; }
      .service-row, .service-row.reverse { flex-direction: column; }
      .footer-grid { grid-template-columns: 1fr 1fr; }
      .hero h1 { font-size: 28px; }
    }
    @media (max-width: 520px) {
      .footer-grid { grid-template-columns: 1fr; }
      .hero-buttons { flex-direction: column; align-items: center; }
    }