/* roulang page: index */
/* ----- 设计变量与全局重置 ----- */
    :root {
      --cyan: #0AEFFF;
      --cyan-dark: #00D4E5;
      --purple: #7C3AED;
      --bg-page: #F8FAFC;
      --bg-white: #FFFFFF;
      --text-primary: #1E293B;
      --text-secondary: #64748B;
      --text-muted: #94A3B8;
      --border-light: #E2E8F0;
      --border-card: #F1F5F9;
      --shadow-sm: 0 1px 3px rgba(0,0,0,0.04), 0 4px 20px rgba(0,0,0,0.03);
      --shadow-md: 0 12px 32px rgba(0,0,0,0.08);
      --radius-card: 16px;
      --radius-btn: 8px;
      --radius-input: 8px;
      --font-sans: 'PingFang SC', 'Microsoft YaHei', 'Hiragino Sans GB', system-ui, -apple-system, sans-serif;
      --font-mono: 'JetBrains Mono', 'Fira Code', 'Courier New', monospace;
      --transition: 0.2s ease;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    html {
      scroll-behavior: smooth;
    }
    body {
      font-family: var(--font-sans);
      background-color: var(--bg-page);
      color: var(--text-primary);
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    a {
      text-decoration: none;
      color: inherit;
    }
    button, input, textarea {
      font-family: inherit;
    }
    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 1.5rem;
    }
    /* 栅格工具 */
    .grid {
      display: grid;
      gap: 24px;
    }
    @media (min-width: 768px) {
      .grid-2 { grid-template-columns: repeat(2, 1fr); }
      .grid-3 { grid-template-columns: repeat(3, 1fr); }
      .grid-4 { grid-template-columns: repeat(4, 1fr); }
    }
    /* 按钮系统 */
    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      font-weight: 600;
      border-radius: var(--radius-btn);
      transition: background var(--transition), box-shadow var(--transition), transform var(--transition);
      cursor: pointer;
      border: none;
      line-height: 1.2;
      text-align: center;
    }
    .btn-primary {
      background: var(--cyan);
      color: #0B1120;
      padding: 12px 28px;
      box-shadow: 0 4px 12px rgba(10, 239, 255, 0.25);
    }
    .btn-primary:hover {
      background: var(--cyan-dark);
      box-shadow: 0 6px 18px rgba(10, 239, 255, 0.4);
      transform: translateY(-1px);
    }
    .btn-secondary {
      background: transparent;
      border: 1.5px solid var(--cyan);
      color: var(--cyan);
      padding: 12px 28px;
    }
    .btn-secondary:hover {
      background: rgba(10, 239, 255, 0.05);
      border-color: var(--cyan-dark);
      color: var(--cyan-dark);
    }
    .btn-lg {
      padding: 16px 36px;
      font-size: 1.125rem;
    }
    .btn-sm {
      padding: 8px 16px;
      font-size: 0.875rem;
    }
    /* 导航 */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      background: rgba(255,255,255,0.85);
      backdrop-filter: blur(12px);
      z-index: 1000;
      transition: background 0.3s, box-shadow 0.3s;
      height: 64px;
      display: flex;
      align-items: center;
    }
    .header.scrolled {
      background: #fff;
      box-shadow: 0 1px 8px rgba(0,0,0,0.04);
    }
    .nav {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
    }
    .logo {
      font-weight: 800;
      font-size: 1.5rem;
      letter-spacing: -0.02em;
      color: var(--text-primary);
      display: flex;
      align-items: center;
      gap: 0.4rem;
    }
    .logo span {
      color: var(--cyan);
      font-weight: 800;
    }
    .nav-links {
      display: flex;
      align-items: center;
      gap: 2rem;
    }
    .nav-links a {
      font-weight: 500;
      color: #475569;
      transition: color 0.2s;
      position: relative;
      padding-bottom: 4px;
    }
    .nav-links a:hover {
      color: var(--cyan);
    }
    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 50%;
      transform: translateX(-50%) scaleX(0);
      width: 100%;
      height: 2px;
      background: var(--cyan);
      transition: transform 0.2s ease;
    }
    .nav-links a:hover::after {
      transform: translateX(-50%) scaleX(1);
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
      background: none;
      border: none;
    }
    .hamburger span {
      width: 24px;
      height: 2px;
      background: #1E293B;
      transition: 0.3s;
    }
    .mobile-menu {
      display: none;
    }
    @media (max-width: 768px) {
      .nav-links { display: none; }
      .hamburger { display: flex; }
      .mobile-menu.active {
        display: flex;
        flex-direction: column;
        position: fixed;
        top: 64px;
        left: 0;
        width: 100%;
        height: calc(100vh - 64px);
        background: rgba(255,255,255,0.96);
        backdrop-filter: blur(20px);
        align-items: center;
        justify-content: center;
        gap: 2.5rem;
        z-index: 999;
      }
      .mobile-menu a {
        font-size: 1.5rem;
        font-weight: 600;
        color: #1E293B;
      }
    }
    /* 区块间距 */
    section {
      padding: 100px 0;
    }
    @media (max-width: 768px) {
      section { padding: 70px 0; }
    }
    /* Hero */
    .hero {
      display: flex;
      align-items: center;
      gap: 3rem;
      min-height: 90vh;
      padding-top: 100px;
    }
    .hero-content {
      flex: 1;
      animation: fadeUp 0.8s ease;
    }
    .hero-title {
      font-size: clamp(3rem, 6vw, 5rem);
      font-weight: 800;
      line-height: 1.1;
      letter-spacing: -0.02em;
      color: #0B1120;
      margin-bottom: 1.5rem;
    }
    .hero-subtitle {
      font-size: 1.25rem;
      color: #475569;
      margin-bottom: 2rem;
      max-width: 480px;
    }
    .hero-actions {
      display: flex;
      gap: 1rem;
      flex-wrap: wrap;
    }
    .hero-visual {
      flex: 1;
      background: url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      border-radius: 24px;
      min-height: 380px;
      box-shadow: var(--shadow-sm);
      position: relative;
      overflow: hidden;
    }
    @media (max-width: 768px) {
      .hero {
        flex-direction: column;
        text-align: center;
      }
      .hero-subtitle { margin: 0 auto 2rem; }
      .hero-actions { justify-content: center; }
      .hero-visual { width: 100%; min-height: 280px; }
    }
    /* 数据看板 */
    .live-stats .grid {
      margin-top: 2rem;
    }
    .stat-card {
      background: var(--bg-white);
      border-radius: var(--radius-card);
      padding: 28px;
      box-shadow: var(--shadow-sm);
      transition: transform 0.3s, box-shadow 0.3s;
    }
    .stat-card:hover {
      transform: translateY(-5px);
      box-shadow: var(--shadow-md);
    }
    .stat-label {
      font-size: 0.9rem;
      color: var(--text-secondary);
      margin-bottom: 8px;
    }
    .stat-number {
      font-family: var(--font-mono);
      font-size: 2.8rem;
      font-weight: 700;
      color: #0B1120;
      line-height: 1.2;
    }
    .stat-trend {
      display: flex;
      align-items: center;
      gap: 4px;
      margin-top: 8px;
      font-weight: 600;
      font-size: 0.9rem;
    }
    .trend-up { color: #10B981; }
    .trend-down { color: #EF4444; }
    /* 服务卡片 */
    .service-card {
      background: #FFFFFF;
      border: 1px solid var(--border-card);
      border-radius: 12px;
      padding: 28px;
      transition: all 0.3s ease;
      display: flex;
      flex-direction: column;
      gap: 12px;
    }
    .service-card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-md);
      border-left: 4px solid var(--cyan);
    }
    .service-icon {
      font-size: 2rem;
      color: var(--cyan);
    }
    .service-title {
      font-size: 1.35rem;
      font-weight: 700;
    }
    /* 对比区块 */
    .compare-wrapper {
      background: #1E293B;
      border-radius: 24px;
      padding: 3rem;
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 2rem;
      color: white;
      background-image: url('/assets/images/coverpic/cover-2.webp');
      background-size: cover;
      background-blend-mode: overlay;
    }
    .team {
      text-align: center;
      flex: 1;
    }
    .team-name {
      font-size: 2rem;
      font-weight: 800;
    }
    .vs {
      font-size: 2.5rem;
      font-weight: 800;
      color: var(--cyan);
    }
    .data-bar {
      height: 8px;
      background: #334155;
      border-radius: 4px;
      margin: 12px 0;
      width: 100%;
    }
    .fill {
      height: 100%;
      background: var(--cyan);
      border-radius: 4px;
      width: 68%;
    }
    @media (max-width: 768px) {
      .compare-wrapper {
        flex-direction: column;
        text-align: center;
      }
    }
    /* FAQ */
    .faq-item {
      border-bottom: 1px solid #F1F5F9;
      padding: 20px 0;
    }
    .faq-question {
      display: flex;
      justify-content: space-between;
      font-weight: 700;
      cursor: pointer;
      font-size: 1.1rem;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease;
      color: #475569;
      line-height: 1.8;
      padding-top: 0;
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      padding-top: 12px;
    }
    /* 表单 */
    .contact-form {
      background: #FFFFFF;
      border-radius: 20px;
      padding: 2.5rem;
      box-shadow: var(--shadow-sm);
      max-width: 600px;
      margin: 0 auto;
    }
    .input-field {
      width: 100%;
      padding: 12px 16px;
      border: 1px solid #E2E8F0;
      border-radius: var(--radius-input);
      margin-bottom: 1rem;
      transition: 0.2s;
    }
    .input-field:focus {
      outline: none;
      border-color: var(--cyan);
      box-shadow: 0 0 0 3px rgba(10,239,255,0.15);
    }
    /* 页脚 */
    .footer {
      background: #0B1120;
      color: #CBD5E1;
      padding: 60px 0 30px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 2rem;
    }
    @media (max-width: 768px) {
      .footer-grid { grid-template-columns: 1fr 1fr; }
    }
    .footer a:hover { color: var(--cyan); }
    @keyframes fadeUp {
      0% { opacity: 0; transform: translateY(20px); }
      100% { opacity: 1; transform: translateY(0); }
    }