/* roulang page: index */
:root {
      --primary: #4E6EF2;
      --primary-rgb: 78, 110, 242;
      --secondary: #7B61FF;
      --success: #00B578;
      --warning: #FF9F0A;
      --danger: #FA5151;
      --bg: #F5F6FA;
      --card: #FFFFFF;
      --text: #1F2329;
      --text-weak: #86909C;
      --star-dark: #0B0E1A;
      --glass-border: rgba(255,255,255,0.15);
      --shadow-sm: 0 2px 8px rgba(0,0,0,0.04), 0 4px 16px rgba(0,0,0,0.04);
      --shadow-hover: 0 4px 12px rgba(0,0,0,0.06), 0 8px 24px rgba(0,0,0,0.06);
      --radius-sm: 8px;
      --radius: 12px;
      --radius-lg: 16px;
      --radius-full: 50px;
      --font: -apple-system, BlinkMacSystemFont, "PingFang SC", "Helvetica Neue", "Microsoft YaHei", sans-serif;
      --transition: 200ms cubic-bezier(0.2, 0.0, 0, 1.0);
      --max-width: 1200px;
      --nav-height: 64px;
    }

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

    html {
      scroll-behavior: smooth;
      font-size: 16px;
    }

    body {
      font-family: var(--font);
      line-height: 1.5;
      color: var(--text);
      background: var(--bg);
      -webkit-font-smoothing: antialiased;
      -moz-osx-font-smoothing: grayscale;
    }

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

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

    button, .btn {
      cursor: pointer;
      font-family: inherit;
      border: none;
      background: none;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      transition: all var(--transition);
      font-weight: 500;
    }

    .container {
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 24px;
    }

    @media (max-width: 768px) {
      .container {
        padding: 0 16px;
      }
    }

    /* 导航栏 */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: var(--nav-height);
      background: rgba(255,255,255,0.92);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
      z-index: 100;
      transition: box-shadow 300ms;
      border-bottom: 1px solid transparent;
    }

    .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;
      height: 100%;
    }

    .logo {
      font-size: 1.5rem;
      font-weight: 700;
      color: var(--primary);
      letter-spacing: 0.5px;
      background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
    }

    .nav-links {
      display: flex;
      align-items: center;
      gap: 32px;
      list-style: none;
    }

    .nav-links a {
      font-size: 1rem;
      font-weight: 400;
      color: var(--text);
      position: relative;
      padding: 8px 0;
    }

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

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

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

    .btn-primary {
      background: var(--primary);
      color: #fff;
      padding: 10px 24px;
      border-radius: var(--radius-full);
      font-weight: 600;
      font-size: 0.95rem;
      transition: all var(--transition);
      box-shadow: 0 4px 10px rgba(var(--primary-rgb), 0.25);
    }

    .btn-primary:hover {
      background: #3D57D9;
      box-shadow: 0 6px 16px rgba(var(--primary-rgb), 0.35);
      transform: scale(1.02);
    }

    .btn-outline {
      background: transparent;
      border: 1px solid rgba(255,255,255,0.7);
      color: #fff;
      padding: 12px 32px;
      border-radius: var(--radius-full);
      font-weight: 600;
    }

    .btn-outline:hover {
      background: rgba(255,255,255,0.1);
      border-color: #fff;
    }

    .nav-toggle {
      display: none;
      flex-direction: column;
      gap: 5px;
      background: none;
      border: none;
      padding: 8px;
      z-index: 101;
    }

    .nav-toggle span {
      display: block;
      width: 24px;
      height: 2px;
      background: var(--text);
      border-radius: 2px;
      transition: var(--transition);
    }

    @media (max-width: 768px) {
      .nav-links {
        position: fixed;
        top: 0;
        right: -100%;
        width: 280px;
        height: 100vh;
        background: #fff;
        flex-direction: column;
        align-items: flex-start;
        padding: 96px 32px 40px;
        gap: 32px;
        box-shadow: -4px 0 20px rgba(0,0,0,0.08);
        transition: right 300ms ease;
        z-index: 100;
      }
      .nav-links.active {
        right: 0;
      }
      .nav-toggle {
        display: flex;
      }
      .nav-links .btn-primary {
        width: 100%;
        justify-content: center;
      }
    }

    /* Hero */
    .hero {
      position: relative;
      padding: 140px 0 100px;
      background: var(--star-dark);
      overflow: hidden;
      display: flex;
      align-items: center;
      justify-content: center;
      text-align: center;
    }

    .stars {
      position: absolute;
      inset: 0;
      pointer-events: none;
    }

    .star-dot {
      position: absolute;
      background: white;
      border-radius: 50%;
      animation: twinkle 3s infinite alternate;
    }

    @keyframes twinkle {
      0% { opacity: 0.2; transform: scale(0.8); }
      100% { opacity: 0.9; transform: scale(1.2); }
    }

    .hero-card {
      position: relative;
      z-index: 2;
      max-width: 720px;
      margin: 0 auto;
      background: rgba(255,255,255,0.08);
      backdrop-filter: blur(24px);
      -webkit-backdrop-filter: blur(24px);
      border: 1px solid var(--glass-border);
      border-radius: var(--radius-lg);
      padding: 48px 40px;
      color: #fff;
    }

    .hero-card h1 {
      font-size: 2.25rem;
      font-weight: 700;
      line-height: 1.2;
      margin-bottom: 16px;
      letter-spacing: -0.3px;
    }

    .hero-card .subtitle {
      font-size: 1.125rem;
      color: rgba(255,255,255,0.8);
      margin-bottom: 32px;
      line-height: 1.6;
    }

    .hero-actions {
      display: flex;
      gap: 16px;
      justify-content: center;
      flex-wrap: wrap;
    }

    @media (max-width: 768px) {
      .hero-card {
        padding: 32px 24px;
        margin: 0 16px;
      }
      .hero-card h1 {
        font-size: 1.75rem;
      }
      .hero-actions {
        flex-direction: column;
        align-items: stretch;
      }
      .btn-outline {
        padding: 12px 24px;
      }
    }

    /* 通用区块 */
    .section {
      padding: 80px 0;
    }

    .section-alt {
      background: var(--card);
    }

    .section-title {
      text-align: center;
      margin-bottom: 48px;
    }

    .section-title h2 {
      font-size: 1.75rem;
      font-weight: 600;
      margin-bottom: 12px;
    }

    .section-title p {
      font-size: 1rem;
      color: var(--text-weak);
    }

    /* 优势卡片 */
    .grid-3 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }

    .advantage-card {
      background: var(--card);
      border-radius: var(--radius);
      padding: 32px 24px;
      box-shadow: var(--shadow-sm);
      transition: all var(--transition);
    }

    .advantage-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
    }

    .icon-wrap {
      width: 48px;
      height: 48px;
      display: flex;
      align-items: center;
      justify-content: center;
      border-radius: var(--radius);
      background: rgba(123, 97, 255, 0.1);
      color: var(--secondary);
      margin-bottom: 20px;
    }

    .advantage-card h3 {
      font-size: 1.25rem;
      font-weight: 600;
      margin-bottom: 8px;
    }

    .advantage-card p {
      font-size: 0.95rem;
      color: var(--text-weak);
    }

    /* 产品卡片 */
    .grid-products {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }

    .product-card {
      background: var(--card);
      border-radius: var(--radius);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
    }

    .product-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
    }

    .product-card img {
      width: 100%;
      height: 200px;
      object-fit: cover;
    }

    .product-body {
      padding: 20px 24px 24px;
    }

    .product-body h3 {
      font-size: 1.2rem;
      margin-bottom: 8px;
    }

    .product-body p {
      color: var(--text-weak);
      font-size: 0.95rem;
      margin-bottom: 16px;
    }

    .link-arrow {
      color: var(--primary);
      font-weight: 500;
      display: inline-flex;
      align-items: center;
      gap: 4px;
      transition: gap var(--transition);
    }

    .link-arrow:hover {
      gap: 8px;
    }

    /* 数据案例 */
    .split-layout {
      display: grid;
      grid-template-columns: 1fr 1.2fr;
      gap: 48px;
      align-items: center;
    }

    .stats-group {
      display: flex;
      flex-direction: column;
      gap: 32px;
    }

    .stat-item h3 {
      font-size: 2.8rem;
      font-weight: 700;
      color: var(--primary);
      line-height: 1.1;
    }

    .stat-item p {
      color: var(--text-weak);
      margin-top: 4px;
    }

    .case-card {
      background: var(--card);
      border-radius: var(--radius);
      padding: 32px;
      box-shadow: var(--shadow-sm);
    }

    .case-card img {
      width: 100%;
      height: 140px;
      object-fit: cover;
      border-radius: var(--radius-sm);
      margin-bottom: 16px;
    }

    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
      display: flex;
      flex-direction: column;
      gap: 12px;
    }

    .faq-item {
      background: #fff;
      border-radius: var(--radius);
      padding: 16px 20px;
      transition: background var(--transition);
    }

    .faq-question {
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-weight: 600;
      cursor: pointer;
      list-style: none;
    }

    .faq-question::-webkit-details-marker {
      display: none;
    }

    .faq-answer {
      margin-top: 12px;
      color: var(--text-weak);
      font-size: 0.95rem;
      line-height: 1.6;
    }

    /* CTA 板块 */
    .cta-section {
      background: var(--star-dark);
      padding: 80px 0;
      text-align: center;
    }

    .cta-section h2 {
      color: #fff;
      font-size: 1.8rem;
      margin-bottom: 32px;
    }

    .cta-form {
      display: flex;
      gap: 12px;
      justify-content: center;
      flex-wrap: wrap;
    }

    .cta-form input {
      padding: 14px 20px;
      border-radius: var(--radius-full);
      border: none;
      width: 320px;
      max-width: 100%;
      font-size: 1rem;
      outline: none;
      transition: box-shadow var(--transition);
    }

    .cta-form input:focus {
      box-shadow: 0 0 0 3px rgba(78,110,242,0.4);
    }

    /* 页脚 */
    .footer {
      background: #0B0E1A;
      color: var(--text-weak);
      padding: 40px 0;
    }

    .footer-grid {
      display: flex;
      justify-content: space-between;
      align-items: center;
      flex-wrap: wrap;
      gap: 20px;
    }

    .footer-links {
      display: flex;
      gap: 24px;
      list-style: none;
    }

    .footer-links a:hover {
      color: #fff;
    }

    @media (max-width: 1024px) {
      .grid-3, .grid-products {
        grid-template-columns: repeat(2, 1fr);
      }
      .split-layout {
        grid-template-columns: 1fr;
      }
    }

    @media (max-width: 600px) {
      .grid-3, .grid-products {
        grid-template-columns: 1fr;
      }
      .footer-grid {
        flex-direction: column;
        text-align: center;
      }
      .footer-links {
        flex-wrap: wrap;
        justify-content: center;
      }
    }