/* roulang page: index */
/* ----- 设计变量与基础重置 ----- */
    :root {
      --primary: #00E5A0;
      --primary-glow: rgba(0, 229, 160, 0.5);
      --secondary: #FFB347;
      --bg-deep: #0A0E27;
      --bg-section: #111640;
      --bg-card: rgba(255, 255, 255, 0.04);
      --bg-dark-input: rgba(255, 255, 255, 0.06);
      --text-primary: rgba(255, 255, 255, 0.92);
      --text-secondary: rgba(255, 255, 255, 0.7);
      --text-muted: rgba(255, 255, 255, 0.5);
      --border-light: rgba(255, 255, 255, 0.08);
      --border-card: rgba(255, 255, 255, 0.12);
      --radius-sm: 12px;
      --radius-md: 16px;
      --radius-lg: 20px;
      --shadow-card: 0 4px 30px rgba(0, 0, 0, 0.3);
      --shadow-hover: 0 8px 50px rgba(0, 229, 160, 0.15);
      --font-sans: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", sans-serif;
      --font-mono: "Inter", "SF Mono", "Roboto Mono", monospace;
      --transition: 0.25s ease;
      --container-max: 1280px;
      --section-gap: 120px;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    html {
      scroll-behavior: smooth;
      background-color: var(--bg-deep);
    }
    body {
      font-family: var(--font-sans);
      background: var(--bg-deep);
      color: var(--text-primary);
      line-height: 1.75;
      -webkit-font-smoothing: antialiased;
      overflow-x: hidden;
    }
    img {
      max-width: 100%;
      display: block;
    }
    a {
      text-decoration: none;
      color: inherit;
      transition: color var(--transition);
    }
    button, input, textarea {
      font-family: inherit;
    }
    .container {
      max-width: var(--container-max);
      margin: 0 auto;
      padding: 0 24px;
    }
    /* 分隔装饰线 */
    .section-divider {
      width: 60px;
      height: 4px;
      background: linear-gradient(90deg, var(--primary), transparent);
      margin-top: 8px;
      border-radius: 4px;
    }
    h2 {
      font-size: clamp(1.8rem, 3.5vw, 2.5rem);
      font-weight: 600;
      letter-spacing: -0.02em;
      color: white;
    }
    /* ----- 导航系统 ----- */
    .site-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 100;
      background: rgba(10, 14, 39, 0.85);
      backdrop-filter: blur(16px);
      -webkit-backdrop-filter: blur(16px);
      border-bottom: 1px solid rgba(255,255,255,0.08);
    }
    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      max-width: var(--container-max);
      margin: 0 auto;
      padding: 0 24px;
      height: 72px;
    }
    .logo {
      display: flex;
      align-items: baseline;
      gap: 6px;
      font-weight: 700;
      font-size: 1.5rem;
      background: linear-gradient(135deg, var(--primary), #a0f0d0);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
      letter-spacing: -0.5px;
    }
    .logo small {
      font-size: 0.75rem;
      font-weight: 400;
      color: var(--text-muted);
      background: none;
      -webkit-text-fill-color: var(--text-muted);
      margin-left: 2px;
    }
    .nav-links {
      display: flex;
      align-items: center;
      gap: 32px;
    }
    .nav-links a {
      font-weight: 500;
      color: var(--text-secondary);
      font-size: 0.95rem;
      transition: color 0.2s;
    }
    .nav-links a:hover {
      color: var(--primary);
    }
    .nav-cta {
      background: var(--primary);
      color: #0A0E27 !important;
      padding: 10px 22px;
      border-radius: 30px;
      font-weight: 600;
      background: var(--primary);
      transition: box-shadow 0.2s, transform 0.2s;
      font-size: 0.9rem;
    }
    .nav-cta:hover {
      box-shadow: 0 0 25px var(--primary-glow);
      transform: scale(1.02);
      color: #0A0E27 !important;
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
      background: transparent;
      border: none;
    }
    .hamburger span {
      width: 25px;
      height: 2px;
      background: white;
      transition: 0.3s;
    }
    /* 移动端菜单 */
    @media (max-width: 768px) {
      .nav-links {
        position: fixed;
        top: 72px;
        left: 0;
        width: 100%;
        background: rgba(10,14,39,0.95);
        backdrop-filter: blur(20px);
        flex-direction: column;
        padding: 32px 24px;
        gap: 24px;
        transform: translateY(-150%);
        transition: transform 0.3s ease;
        border-bottom: 1px solid var(--border-light);
      }
      .nav-links.active {
        transform: translateY(0);
      }
      .hamburger {
        display: flex;
      }
    }
    /* ----- Hero 首屏 ----- */
    .hero {
      padding: 140px 0 100px;
      display: flex;
      align-items: center;
      min-height: 100vh;
      background: radial-gradient(circle at 30% 40%, rgba(0,229,160,0.08) 0%, transparent 50%);
    }
    .hero-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 60px;
      align-items: center;
    }
    .hero-left h1 {
      font-size: clamp(2.5rem, 5vw, 4rem);
      font-weight: 700;
      letter-spacing: -0.02em;
      line-height: 1.2;
      margin-bottom: 24px;
    }
    .hero-left .subtitle {
      font-size: 1.2rem;
      color: var(--text-secondary);
      margin-bottom: 40px;
      max-width: 450px;
    }
    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .btn-primary {
      background: var(--primary);
      color: #0A0E27;
      padding: 14px 32px;
      border-radius: 12px;
      font-weight: 600;
      border: none;
      cursor: pointer;
      transition: 0.2s;
      box-shadow: 0 0 20px rgba(0,229,160,0.25);
    }
    .btn-primary:hover {
      box-shadow: 0 0 35px var(--primary-glow);
      transform: translateY(-2px);
    }
    .btn-secondary {
      background: transparent;
      border: 1px solid var(--primary);
      color: var(--primary);
      padding: 14px 32px;
      border-radius: 12px;
      font-weight: 600;
      transition: 0.2s;
    }
    .btn-secondary:hover {
      background: rgba(0,229,160,0.1);
      border-color: var(--primary);
    }
    .data-dashboard {
      background: rgba(255,255,255,0.03);
      backdrop-filter: blur(20px);
      border: 1px solid rgba(255,255,255,0.1);
      border-radius: 24px;
      padding: 32px 28px;
      box-shadow: var(--shadow-card);
    }
    .metric-row {
      display: flex;
      justify-content: space-between;
      align-items: baseline;
      margin-bottom: 28px;
    }
    .metric-label {
      color: var(--text-secondary);
      font-size: 0.95rem;
    }
    .metric-value {
      font-family: var(--font-mono);
      font-size: 2rem;
      font-weight: 600;
      color: white;
      text-shadow: 0 0 20px rgba(0,229,160,0.6);
    }
    @media (max-width: 768px) {
      .hero-grid {
        grid-template-columns: 1fr;
        text-align: center;
      }
      .hero-left .subtitle {
        margin-left: auto;
        margin-right: auto;
      }
      .hero-buttons {
        justify-content: center;
      }
    }
    /* ----- 服务卡片 ----- */
    .services {
      padding: var(--section-gap) 0;
      background: var(--bg-section);
    }
    .service-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 28px;
      margin-top: 48px;
    }
    .service-card {
      background: var(--bg-card);
      backdrop-filter: blur(16px);
      border: 1px solid var(--border-light);
      border-radius: var(--radius-lg);
      padding: 36px 28px;
      transition: all 0.25s;
      position: relative;
    }
    .service-card:first-child {
      margin-top: -20px;
    }
    .service-card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-hover);
      border-color: rgba(0,229,160,0.2);
    }
    .icon-circle {
      width: 52px;
      height: 52px;
      background: rgba(0,229,160,0.12);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      margin-bottom: 24px;
      color: var(--primary);
      font-size: 1.8rem;
    }
    .service-card h3 {
      font-size: 1.5rem;
      margin-bottom: 8px;
    }
    .stat-highlight {
      font-family: var(--font-mono);
      color: var(--secondary);
      font-weight: 600;
      font-size: 1.1rem;
      margin: 12px 0;
    }
    @media (max-width: 1024px) {
      .service-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .service-card:first-child {
        margin-top: 0;
      }
    }
    @media (max-width: 768px) {
      .service-grid {
        grid-template-columns: 1fr;
      }
    }
    /* ----- 数据对比 ----- */
    .data-compare {
      padding: var(--section-gap) 0;
    }
    .compare-container {
      display: flex;
      align-items: center;
      gap: 24px;
      margin-top: 48px;
    }
    .compare-card {
      flex: 1;
      background: rgba(255,255,255,0.03);
      backdrop-filter: blur(12px);
      border-radius: 20px;
      padding: 32px;
      border: 1px solid var(--border-light);
    }
    .compare-card.highlight {
      border: 1px solid rgba(0,229,160,0.3);
      background: rgba(0,229,160,0.04);
      box-shadow: 0 0 40px rgba(0,229,160,0.1);
    }
    .vs-badge {
      background: linear-gradient(135deg, #FFB347, #ff8c1a);
      width: 56px;
      height: 56px;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 700;
      color: #0A0E27;
      font-size: 1.2rem;
    }
    .compare-item {
      display: flex;
      justify-content: space-between;
      margin: 20px 0;
    }
    @media (max-width: 768px) {
      .compare-container {
        flex-direction: column;
      }
      .vs-badge {
        margin: 12px 0;
      }
    }
    /* ----- FAQ ----- */
    .faq {
      padding: var(--section-gap) 0;
      background: var(--bg-section);
    }
    .faq-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 24px;
      margin-top: 40px;
    }
    .faq-item {
      background: rgba(255,255,255,0.02);
      border: 1px solid var(--border-light);
      border-radius: 16px;
      padding: 20px;
      cursor: pointer;
      transition: background 0.2s;
    }
    .faq-question {
      font-weight: 600;
      display: flex;
      justify-content: space-between;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      color: var(--text-secondary);
    }
    @media (max-width: 768px) {
      .faq-grid {
        grid-template-columns: 1fr;
      }
    }
    /* ----- 联系表单 ----- */
    .contact {
      padding: var(--section-gap) 0;
      background: #080B1F;
    }
    .form-card {
      background: rgba(255,255,255,0.03);
      backdrop-filter: blur(24px);
      border: 1px solid rgba(255,255,255,0.08);
      border-radius: 24px;
      padding: 48px;
      max-width: 680px;
      margin: 0 auto;
    }
    .form-input {
      width: 100%;
      background: rgba(255,255,255,0.06);
      border: 1px solid rgba(255,255,255,0.1);
      border-radius: 12px;
      padding: 14px 18px;
      color: white;
      margin-bottom: 20px;
      transition: 0.2s;
    }
    .form-input:focus {
      border-color: var(--primary);
      box-shadow: 0 0 12px rgba(0,229,160,0.3);
      outline: none;
    }
    /* ----- 页脚 ----- */
    .footer {
      padding: 60px 0 30px;
      border-top: 1px solid rgba(255,255,255,0.05);
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
    }
    @media (max-width: 768px) {
      .footer-grid {
        grid-template-columns: 1fr;
      }
    }