/* roulang page: index */
:root {
      --primary: #E94057;
      --primary-hover: #D12E44;
      --secondary: #1A1A2E;
      --accent: #00D2FF;
      --neutral-bg: #F5F0EB;
      --white: #FFFFFF;
      --text-dark: #1A1A2E;
      --text-body: #3A3A4A;
      --text-muted: #6B6B7B;
      --card-shadow: 0 2px 12px rgba(26,26,46,0.06);
      --card-shadow-hover: 0 8px 28px rgba(233,64,87,0.12);
      --border-light: rgba(0,0,0,0.04);
      --radius-card: 12px;
      --radius-button: 8px;
      --radius-input: 6px;
      --transition: all 0.25s ease;
    }
    * {
      box-sizing: border-box;
    }
    body {
      font-family: 'PingFang SC', 'Microsoft YaHei', 'Noto Sans SC', sans-serif;
      margin: 0;
      background-color: var(--white);
      color: var(--text-body);
      line-height: 1.75;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }
    h1, h2, h3, .font-heading {
      font-family: 'PingFang SC', 'Microsoft YaHei', 'Noto Sans SC', sans-serif;
      font-weight: 700;
      color: var(--text-dark);
      letter-spacing: -0.02em;
    }
    .number-font {
      font-family: 'Inter', 'DIN Alternate', 'PingFang SC', sans-serif;
      font-weight: 700;
    }
    .container-main {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 24px;
    }
    @media (min-width: 1024px) {
      .container-main {
        padding: 0 40px;
      }
    }
    /* 导航 */
    .navbar {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 64px;
      background: rgba(255,255,255,0.92);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
      z-index: 50;
      display: flex;
      align-items: center;
      border-bottom: 1px solid rgba(0,0,0,0.02);
      transition: var(--transition);
    }
    .nav-container {
      width: 100%;
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 24px;
      display: flex;
      justify-content: space-between;
      align-items: center;
    }
    .logo {
      font-weight: 800;
      font-size: 1.5rem;
      color: var(--text-dark);
      letter-spacing: -0.5px;
      text-decoration: none;
      display: flex;
      align-items: center;
      gap: 4px;
    }
    .logo i {
      color: var(--primary);
      font-size: 1.4rem;
    }
    .nav-links {
      display: none;
      gap: 32px;
      align-items: center;
    }
    .nav-links a {
      text-decoration: none;
      color: var(--text-body);
      font-weight: 500;
      font-size: 0.95rem;
      transition: color 0.2s;
      position: relative;
    }
    .nav-links a:hover,
    .nav-links a.active {
      color: var(--primary);
    }
    .nav-links a.active::after {
      content: '';
      position: absolute;
      bottom: -6px;
      left: 0;
      width: 100%;
      height: 2px;
      background: var(--primary);
      border-radius: 2px;
    }
    .btn-primary-sm {
      background: var(--primary);
      color: white;
      padding: 8px 20px;
      border-radius: var(--radius-button);
      font-weight: 600;
      font-size: 0.9rem;
      text-decoration: none;
      border: none;
      cursor: pointer;
      transition: var(--transition);
      white-space: nowrap;
    }
    .btn-primary-sm:hover {
      background: var(--primary-hover);
    }
    .mobile-menu-btn {
      background: none;
      border: none;
      font-size: 1.8rem;
      color: var(--text-dark);
      cursor: pointer;
    }
    .mobile-menu {
      display: none;
      position: fixed;
      top: 64px;
      left: 0;
      width: 100%;
      height: calc(100vh - 64px);
      background: rgba(255,255,255,0.98);
      backdrop-filter: blur(20px);
      flex-direction: column;
      align-items: center;
      justify-content: center;
      gap: 32px;
      z-index: 49;
    }
    .mobile-menu.open {
      display: flex;
    }
    .mobile-menu a {
      font-size: 1.4rem;
      font-weight: 600;
      color: var(--text-dark);
      text-decoration: none;
    }
    @media (min-width: 769px) {
      .nav-links {
        display: flex;
      }
      .mobile-menu-btn {
        display: none;
      }
    }
    /* 按钮系统 */
    .btn-primary {
      background: var(--primary);
      color: white;
      padding: 12px 28px;
      border-radius: var(--radius-button);
      font-weight: 600;
      text-decoration: none;
      display: inline-block;
      transition: var(--transition);
      border: none;
      cursor: pointer;
      box-shadow: 0 4px 10px rgba(233,64,87,0.2);
    }
    .btn-primary:hover {
      background: var(--primary-hover);
      box-shadow: 0 6px 18px rgba(233,64,87,0.3);
    }
    .btn-outline {
      background: transparent;
      color: var(--primary);
      border: 2px solid var(--primary);
      padding: 12px 28px;
      border-radius: var(--radius-button);
      font-weight: 600;
      text-decoration: none;
      display: inline-block;
      transition: var(--transition);
    }
    .btn-outline:hover {
      background: var(--primary);
      color: white;
    }
    .btn-neon {
      background: transparent;
      color: var(--accent);
      border: 2px solid var(--accent);
      padding: 14px 32px;
      border-radius: var(--radius-button);
      font-weight: 600;
      text-decoration: none;
      display: inline-block;
      transition: var(--transition);
      box-shadow: 0 0 0px rgba(0,210,255,0);
    }
    .btn-neon:hover {
      box-shadow: 0 0 18px rgba(0,210,255,0.5);
      background: rgba(0,210,255,0.08);
    }
    /* Hero */
    .hero-section {
      padding-top: 64px;
      min-height: 100vh;
      display: flex;
      align-items: center;
      background: radial-gradient(circle at 20% 30%, rgba(233,64,87,0.08) 0%, transparent 50%),
                  radial-gradient(circle at 80% 70%, rgba(0,210,255,0.1) 0%, transparent 50%),
                  var(--secondary);
      position: relative;
      overflow: hidden;
    }
    .hero-grid {
      display: flex;
      flex-wrap: wrap;
      align-items: center;
      gap: 40px;
    }
    .hero-left {
      flex: 1 1 50%;
      color: #F5F0EB;
    }
    .hero-left h1 {
      font-size: 3rem;
      line-height: 1.2;
      color: white;
      margin-bottom: 20px;
      font-weight: 800;
    }
    .hero-left .subtitle {
      font-size: 1.2rem;
      color: rgba(245,240,235,0.85);
      margin-bottom: 32px;
    }
    .hero-right {
      flex: 1 1 45%;
      position: relative;
      border-radius: 24px;
      overflow: hidden;
      box-shadow: 0 20px 40px rgba(0,0,0,0.4);
    }
    .hero-right img {
      width: 100%;
      height: auto;
      display: block;
    }
    @media (max-width: 768px) {
      .hero-left h1 {
        font-size: 2.2rem;
      }
      .hero-grid {
        flex-direction: column;
        text-align: center;
      }
      .hero-right {
        width: 100%;
      }
    }
    /* 板块通用 */
    .section {
      padding: 80px 0;
    }
    .section-bg-warm {
      background-color: var(--neutral-bg);
    }
    .section-title {
      font-size: 2.2rem;
      margin-bottom: 12px;
      text-align: center;
    }
    .section-desc {
      color: var(--text-muted);
      text-align: center;
      max-width: 600px;
      margin: 0 auto 48px;
    }
    /* 卡片 */
    .card {
      background: var(--white);
      border-radius: var(--radius-card);
      box-shadow: var(--card-shadow);
      border: 1px solid var(--border-light);
      transition: var(--transition);
      overflow: hidden;
    }
    .card:hover {
      transform: translateY(-6px);
      box-shadow: var(--card-shadow-hover);
    }
    .feature-icon {
      font-size: 2.4rem;
      color: var(--accent);
      margin-bottom: 16px;
    }
    .scene-img {
      width: 100%;
      height: 200px;
      object-fit: cover;
    }
    .data-number {
      font-size: 2.6rem;
      color: var(--accent);
      font-family: 'Inter', sans-serif;
      font-weight: 700;
      margin-bottom: 4px;
    }
    /* FAQ */
    .faq-item {
      border-bottom: 1px solid rgba(0,0,0,0.05);
      background: transparent;
    }
    .faq-question {
      background: var(--neutral-bg);
      padding: 16px 20px;
      font-weight: 600;
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
      color: var(--text-dark);
      border-radius: 4px;
      margin-bottom: 2px;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s ease;
      background: white;
      padding: 0 20px;
    }
    .faq-answer.open {
      max-height: 200px;
      padding: 16px 20px;
    }
    .faq-toggle {
      font-weight: 300;
      font-size: 1.3rem;
    }
    /* CTA 深色区 */
    .cta-dark {
      background: var(--secondary);
      position: relative;
      overflow: hidden;
    }
    .cta-dark::before {
      content: "";
      position: absolute;
      width: 300px;
      height: 300px;
      border: 2px solid rgba(0,210,255,0.2);
      border-radius: 50%;
      top: -80px;
      right: -80px;
      box-shadow: 0 0 35px rgba(0,210,255,0.3);
    }
    /* 页脚 */
    .footer-grid {
      display: grid;
      grid-template-columns: repeat(4,1fr);
      gap: 24px;
    }
    @media (max-width: 768px) {
      .footer-grid {
        grid-template-columns: repeat(2,1fr);
      }
    }
    @media (max-width: 480px) {
      .footer-grid {
        grid-template-columns: 1fr;
      }
    }
    .footer a {
      color: #cbd5e1;
      text-decoration: none;
      font-size: 0.9rem;
    }
    .footer a:hover {
      color: white;
    }