/* roulang page: index */
:root {
      --primary-deep: #0B1A2F;
      --accent-blue: #4E6EF2;
      --accent-green: #00B578;
      --accent-purple: #7C5CFC;
      --bg-light: #F5F6FA;
      --card-white: #FFFFFF;
      --text-primary: #1F2329;
      --text-secondary: #86909C;
      --border-light: #E5E8EF;
      --radius-lg: 16px;
      --radius-md: 12px;
      --radius-sm: 8px;
      --shadow-card: 0 4px 20px rgba(0,0,0,0.04), 0 1px 4px rgba(0,0,0,0.02);
      --shadow-hover: 0 8px 30px rgba(0,0,0,0.08);
      --transition: cubic-bezier(0.25, 0.1, 0.25, 1.0);
      --font-stack: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    body {
      font-family: var(--font-stack);
      background-color: var(--bg-light);
      color: var(--text-primary);
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
    }
    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 40px;
    }
    @media (max-width: 1024px) {
      .container { padding: 0 24px; }
    }
    @media (max-width: 768px) {
      .container { padding: 0 16px; }
    }
    /* 导航 */
    .nav {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 1000;
      transition: background 0.3s, box-shadow 0.3s, backdrop-filter 0.3s;
      background: transparent;
      padding: 16px 0;
    }
    .nav.scrolled {
      background: rgba(255,255,255,0.85);
      backdrop-filter: blur(10px);
      box-shadow: 0 1px 0 var(--border-light);
      padding: 12px 0;
    }
    .nav .container {
      display: flex;
      align-items: center;
      justify-content: space-between;
    }
    .logo {
      font-size: 1.5rem;
      font-weight: 700;
      color: white;
      display: flex;
      align-items: center;
      gap: 8px;
      text-decoration: none;
      transition: color 0.3s;
      letter-spacing: 1px;
    }
    .nav.scrolled .logo {
      color: var(--text-primary);
    }
    .logo-icon {
      font-size: 1.8rem;
      line-height: 1;
    }
    .nav-links {
      display: flex;
      gap: 32px;
      align-items: center;
    }
    .nav-links a {
      text-decoration: none;
      font-size: 15px;
      font-weight: 500;
      color: rgba(255,255,255,0.9);
      transition: color 0.2s;
    }
    .nav.scrolled .nav-links a {
      color: var(--text-primary);
    }
    .nav-links a:hover {
      color: var(--accent-blue);
    }
    .btn-primary-small {
      background: var(--accent-blue);
      color: white !important;
      padding: 10px 20px;
      border-radius: var(--radius-md);
      font-weight: 600;
      transition: all 0.2s;
      border: none;
      cursor: pointer;
      text-decoration: none;
      display: inline-block;
    }
    .btn-primary-small:hover {
      filter: brightness(1.1);
      box-shadow: 0 0 12px rgba(78,110,242,0.5);
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
      background: transparent;
      border: none;
    }
    .hamburger span {
      width: 24px;
      height: 2px;
      background: white;
      transition: 0.3s;
    }
    .nav.scrolled .hamburger span {
      background: var(--text-primary);
    }
    @media (max-width: 1024px) {
      .nav-links { display: none; }
      .hamburger { display: flex; }
      .mobile-menu {
        position: fixed;
        top: 0;
        left: 0;
        width: 100%;
        height: 100vh;
        background: white;
        display: flex;
        flex-direction: column;
        justify-content: center;
        align-items: center;
        gap: 32px;
        transform: translateY(-100%);
        transition: transform 0.3s ease;
        z-index: 999;
      }
      .mobile-menu.open {
        transform: translateY(0);
      }
      .mobile-menu a {
        font-size: 20px;
        color: var(--text-primary);
        text-decoration: none;
        font-weight: 600;
      }
    }
    /* Hero */
    .hero {
      background: var(--primary-deep);
      position: relative;
      overflow: hidden;
      min-height: 100vh;
      display: flex;
      align-items: center;
      padding: 120px 0 80px;
    }
    .hero-bg {
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      mix-blend-mode: soft-light;
      opacity: 0.6;
    }
    .particles {
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      pointer-events: none;
    }
    .hero .container {
      display: flex;
      align-items: center;
      gap: 48px;
      position: relative;
      z-index: 2;
      flex-wrap: wrap;
    }
    .hero-text {
      flex: 1 1 400px;
    }
    .hero h1 {
      font-size: 44px;
      font-weight: 800;
      line-height: 1.2;
      color: white;
      margin-bottom: 24px;
    }
    .hero p {
      font-size: 18px;
      color: var(--text-secondary);
      margin-bottom: 32px;
      max-width: 500px;
    }
    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .btn-primary {
      background: var(--accent-blue);
      color: white;
      padding: 12px 28px;
      border-radius: var(--radius-md);
      font-weight: 600;
      text-decoration: none;
      transition: all 0.2s;
      border: none;
      display: inline-block;
    }
    .btn-primary:hover {
      filter: brightness(1.1);
      box-shadow: 0 0 15px rgba(78,110,242,0.6);
    }
    .btn-outline {
      background: transparent;
      border: 1.5px solid var(--accent-blue);
      color: var(--accent-blue);
      padding: 12px 28px;
      border-radius: var(--radius-md);
      font-weight: 600;
      text-decoration: none;
      transition: 0.2s;
    }
    .btn-outline:hover {
      background: rgba(78,110,242,0.05);
    }
    .hero-visual {
      flex: 1 1 400px;
      background: rgba(255,255,255,0.05);
      backdrop-filter: blur(8px);
      border-radius: var(--radius-lg);
      padding: 32px;
      min-height: 300px;
      display: flex;
      align-items: center;
      justify-content: center;
      border: 1px solid rgba(255,255,255,0.1);
    }
    @media (max-width: 768px) {
      .hero h1 { font-size: 36px; }
      .hero-buttons { flex-direction: column; }
    }
    /* 通用板块 */
    section {
      padding: 100px 0;
    }
    .section-title {
      font-size: 30px;
      font-weight: 700;
      margin-bottom: 16px;
    }
    .section-sub {
      color: var(--text-secondary);
      margin-bottom: 48px;
    }
    /* 指标看板 */
    .metrics-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
    }
    .metric-card {
      background: var(--card-white);
      border-radius: var(--radius-lg);
      padding: 32px;
      box-shadow: var(--shadow-card);
      text-align: center;
    }
    .metric-number {
      font-size: 48px;
      font-weight: 700;
      color: var(--accent-blue);
      line-height: 1;
      margin: 12px 0;
    }
    .metric-label {
      color: var(--text-secondary);
      font-size: 14px;
    }
    @media (max-width: 768px) {
      .metrics-grid { grid-template-columns: 1fr 1fr; }
    }
    /* 服务矩阵 */
    .services-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .service-card {
      background: white;
      border-radius: var(--radius-lg);
      padding: 28px;
      display: flex;
      gap: 20px;
      align-items: flex-start;
      box-shadow: var(--shadow-card);
      transition: all 0.3s;
    }
    .service-card:hover {
      transform: translateY(-2px);
      box-shadow: var(--shadow-hover);
    }
    .service-icon {
      width: 56px;
      height: 56px;
      background: #F0F3FF;
      border-radius: var(--radius-sm);
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 24px;
      color: var(--accent-blue);
      transition: 0.3s;
    }
    .service-card:hover .service-icon {
      transform: scale(1.1);
      box-shadow: 0 0 15px rgba(78,110,242,0.3);
    }
    .tag {
      background: rgba(124,92,252,0.1);
      color: var(--accent-purple);
      font-size: 12px;
      padding: 4px 10px;
      border-radius: 20px;
      display: inline-block;
      margin-top: 12px;
    }
    @media (max-width: 1024px) {
      .services-grid { grid-template-columns: 1fr 1fr; }
    }
    @media (max-width: 768px) {
      .services-grid { grid-template-columns: 1fr; }
    }
    /* 对比 */
    .compare-row {
      display: flex;
      gap: 32px;
      align-items: center;
    }
    .compare-card {
      flex: 1;
      background: white;
      border-radius: var(--radius-lg);
      padding: 32px;
      box-shadow: var(--shadow-card);
    }
    .compare-left {
      opacity: 0.7;
      background: #f0f2f5;
    }
    .compare-right {
      border-left: 4px solid var(--accent-blue);
    }
    .compare-vs {
      font-weight: 700;
      color: var(--accent-blue);
      font-size: 24px;
    }
    @media (max-width: 768px) {
      .compare-row { flex-direction: column; }
    }
    /* FAQ */
    .faq-item {
      background: white;
      border-bottom: 1px solid var(--border-light);
      padding: 20px 0;
      cursor: pointer;
    }
    .faq-question {
      display: flex;
      justify-content: space-between;
      font-weight: 600;
      font-size: 18px;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      background: #F8F9FC;
      padding: 0 24px;
      border-radius: 8px;
      margin-top: 8px;
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      padding: 24px;
    }
    /* CTA 表单 */
    .cta-section {
      background: linear-gradient(135deg, #0B1A2F 0%, #162B48 100%);
    }
    .cta-card {
      background: white;
      border-radius: var(--radius-lg);
      padding: 48px;
      max-width: 700px;
      margin: 0 auto;
      box-shadow: 0 20px 40px rgba(0,0,0,0.2);
    }
    .form-group {
      margin-bottom: 20px;
    }
    .form-group input, .form-group textarea {
      width: 100%;
      padding: 14px;
      background: #F5F6FA;
      border: none;
      border-radius: var(--radius-md);
      font-size: 16px;
      transition: 0.2s;
      border-bottom: 2px solid transparent;
    }
    .form-group input:focus {
      outline: none;
      border-bottom: 2px solid var(--accent-blue);
      background: white;
    }
    .btn-submit {
      width: 100%;
      background: var(--accent-blue);
      color: white;
      border: none;
      padding: 16px;
      border-radius: var(--radius-md);
      font-size: 18px;
      font-weight: 600;
      cursor: pointer;
    }
    /* 页脚 */
    .footer {
      background: var(--primary-deep);
      color: var(--text-secondary);
      padding: 60px 0 30px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 32px;
    }
    .footer a {
      color: var(--text-secondary);
      text-decoration: none;
    }
    .footer a:hover { color: var(--accent-blue); }
    @media (max-width: 768px) {
      .footer-grid { grid-template-columns: 1fr; }
    }
    .copyright {
      border-top: 1px solid rgba(255,255,255,0.1);
      margin-top: 40px;
      padding-top: 20px;
    }