/* roulang page: index */
/* ----- 设计变量 ----- */
    :root {
      --primary-deep: #1E2F2B;
      --primary-graphite: #2C3A37;
      --accent-signal: #00B4A6;
      --accent-hover: #00998C;
      --accent-light: rgba(0, 180, 166, 0.08);
      --warning-amber: #F59E0B;
      --bg-page: #FAFBF8;
      --bg-light: #F3F5F2;
      --bg-white: #FFFFFF;
      --text-main: #1A1F1D;
      --text-secondary: #5F6B67;
      --text-muted: #8E9995;
      --border-light: #E2E6E3;
      --border-card: #E2E6E3;
      --shadow-sm: 0 1px 3px rgba(0,0,0,0.04);
      --shadow-hover: 0 6px 18px rgba(0,0,0,0.07);
      --radius-sm: 6px;
      --radius-md: 8px;
      --radius-lg: 12px;
      --font-sans: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", "Noto Sans SC", system-ui, -apple-system, sans-serif;
      --font-mono: "Inter", "SF Pro Display", system-ui, monospace;
      --max-width: 1200px;
      --nav-height: 64px;
    }
    
    /* ----- 全局重置 ----- */
    *, *::before, *::after {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }
    html {
      scroll-behavior: smooth;
    }
    body {
      font-family: var(--font-sans);
      font-size: 16px;
      font-weight: 400;
      line-height: 1.7;
      color: var(--text-main);
      background-color: var(--bg-page);
      -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 0.2s ease;
    }
    button, .btn {
      cursor: pointer;
      font-family: inherit;
      border: none;
      background: none;
    }
    ul, ol {
      list-style: none;
    }
    .container {
      width: 100%;
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 24px;
    }
    
    /* ----- 导航 ----- */
    .site-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: var(--nav-height);
      background: var(--bg-white);
      border-bottom: 1px solid var(--border-light);
      box-shadow: 0 1px 2px rgba(0,0,0,0.02);
      z-index: 1000;
      display: flex;
      align-items: center;
    }
    .header-inner {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
    }
    .logo {
      font-size: 1.4rem;
      font-weight: 700;
      color: var(--primary-deep);
      letter-spacing: -0.3px;
      display: flex;
      align-items: center;
      gap: 6px;
    }
    .logo span {
      color: var(--accent-signal);
    }
    .nav-links {
      display: flex;
      align-items: center;
      gap: 32px;
    }
    .nav-links a {
      font-size: 0.95rem;
      font-weight: 500;
      color: var(--text-main);
      position: relative;
      padding: 6px 0;
    }
    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--accent-signal);
      transition: width 0.2s ease;
    }
    .nav-links a:hover::after,
    .nav-links a.active::after {
      width: 100%;
    }
    .nav-cta {
      display: flex;
      align-items: center;
      gap: 12px;
    }
    .btn-primary {
      background: var(--accent-signal);
      color: white;
      font-weight: 600;
      padding: 10px 24px;
      border-radius: var(--radius-sm);
      transition: background 0.2s ease;
      display: inline-flex;
      align-items: center;
      justify-content: center;
    }
    .btn-primary:hover {
      background: var(--accent-hover);
    }
    .btn-outline {
      background: transparent;
      border: 2px solid var(--accent-signal);
      color: var(--accent-signal);
      font-weight: 600;
      padding: 8px 22px;
      border-radius: var(--radius-sm);
      transition: background 0.2s, color 0.2s;
    }
    .btn-outline:hover {
      background: var(--accent-light);
    }
    .menu-toggle {
      display: none;
      background: none;
      border: none;
      font-size: 1.8rem;
      color: var(--primary-deep);
      cursor: pointer;
    }
    
    /* 移动端导航 */
    @media (max-width: 768px) {
      .nav-links, .nav-cta .btn-outline {
        display: none;
      }
      .menu-toggle {
        display: block;
      }
      .nav-cta .btn-primary {
        padding: 8px 18px;
        font-size: 0.9rem;
      }
      #menu-checkbox:checked ~ .mobile-menu {
        display: flex;
      }
    }
    .mobile-menu {
      display: none;
      position: fixed;
      top: var(--nav-height);
      left: 0;
      width: 100%;
      background: var(--bg-page);
      flex-direction: column;
      padding: 24px;
      gap: 20px;
      border-bottom: 1px solid var(--border-light);
      z-index: 999;
    }
    .mobile-menu a {
      font-size: 1.1rem;
      font-weight: 500;
      color: var(--text-main);
      padding: 8px 0;
    }
    input#menu-checkbox {
      display: none;
    }
    
    /* ----- 通用板块 ----- */
    section {
      padding: 80px 0;
    }
    .section-title {
      font-size: 2rem;
      font-weight: 600;
      color: var(--text-main);
      margin-bottom: 16px;
      line-height: 1.3;
    }
    .section-subtitle {
      font-size: 1.1rem;
      color: var(--text-secondary);
      max-width: 680px;
      margin-bottom: 48px;
    }
    
    /* ----- Hero ----- */
    .hero {
      padding-top: calc(var(--nav-height) + 60px);
      padding-bottom: 80px;
      display: flex;
      align-items: center;
      min-height: 70vh;
      background-color: var(--bg-page);
      background-image: radial-gradient(circle at 20% 30%, rgba(0,180,166,0.03) 0%, transparent 40%);
    }
    .hero-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 40px;
      align-items: center;
    }
    .hero-content h1 {
      font-size: 2.8rem;
      font-weight: 700;
      line-height: 1.2;
      color: var(--primary-deep);
      margin-bottom: 20px;
      letter-spacing: -0.5px;
    }
    .hero-content p {
      font-size: 1.2rem;
      color: var(--text-secondary);
      margin-bottom: 32px;
      max-width: 500px;
    }
    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .hero-image {
      background: url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      background-color: #e0e4df;
      border-radius: var(--radius-lg);
      height: 380px;
      width: 100%;
      box-shadow: var(--shadow-sm);
      border: 1px solid var(--border-light);
    }
    
    /* ----- 优势区（不对称栅格）----- */
    .features-grid {
      display: grid;
      grid-template-columns: 1.5fr 1fr;
      gap: 24px;
      margin-top: 40px;
    }
    .feature-large {
      background: var(--bg-white);
      border: 1px solid var(--border-card);
      border-radius: var(--radius-md);
      padding: 32px;
      display: flex;
      flex-direction: column;
      justify-content: center;
      transition: box-shadow 0.25s ease, border-color 0.25s;
      background-image: url('/assets/images/coverpic/cover-1.webp');
      background-size: cover;
      background-position: right center;
      background-blend-mode: overlay;
      background-color: rgba(255,255,255,0.9);
    }
    .feature-large:hover, .feature-small:hover {
      border-color: var(--accent-signal);
      box-shadow: var(--shadow-hover);
    }
    .feature-small-group {
      display: flex;
      flex-direction: column;
      gap: 24px;
    }
    .feature-small {
      background: var(--bg-white);
      border: 1px solid var(--border-card);
      border-radius: var(--radius-md);
      padding: 24px;
      transition: 0.25s;
    }
    .feature-icon {
      font-size: 2rem;
      color: var(--accent-signal);
      margin-bottom: 16px;
    }
    .feature-title {
      font-size: 1.3rem;
      font-weight: 600;
      margin-bottom: 8px;
    }
    
    /* ----- 功能分组 ----- */
    .capability-tabs {
      display: flex;
      gap: 24px;
      border-bottom: 2px solid var(--border-light);
      margin-bottom: 32px;
      flex-wrap: wrap;
    }
    .capability-tab {
      padding-bottom: 12px;
      font-weight: 600;
      color: var(--text-secondary);
      cursor: pointer;
      transition: 0.2s;
      border-bottom: 2px solid transparent;
    }
    .capability-tab.active {
      color: var(--accent-signal);
      border-bottom-color: var(--accent-signal);
    }
    .capability-panel {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 32px;
      align-items: center;
      background: var(--bg-light);
      border-radius: var(--radius-md);
      padding: 32px;
    }
    .capability-img {
      background: url('/assets/images/coverpic/cover-2.webp') center/cover no-repeat;
      height: 220px;
      border-radius: var(--radius-md);
    }
    
    /* ----- 场景卡片横向滚动 ----- */
    .scroller {
      display: flex;
      gap: 24px;
      overflow-x: auto;
      padding-bottom: 16px;
      scroll-snap-type: x mandatory;
    }
    .scene-card {
      flex: 0 0 320px;
      scroll-snap-align: start;
      background: var(--bg-white);
      border: 1px solid var(--border-card);
      border-radius: var(--radius-md);
      padding: 24px;
      transition: transform 0.25s, box-shadow 0.25s;
    }
    .scene-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
    }
    
    /* ----- 案例卡片 & 数据指标 ----- */
    .metrics-bar {
      background: var(--primary-deep);
      color: white;
      border-radius: var(--radius-md);
      padding: 32px;
      display: flex;
      justify-content: space-around;
      flex-wrap: wrap;
      margin-bottom: 48px;
    }
    .metric-number {
      font-family: var(--font-mono);
      font-size: 2.2rem;
      font-weight: 700;
      color: var(--accent-signal);
    }
    .case-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
      gap: 24px;
    }
    .case-card {
      background: var(--bg-white);
      border: 1px solid var(--border-card);
      border-radius: var(--radius-md);
      padding: 24px;
    }
    .case-quote {
      border-left: 4px solid var(--accent-signal);
      padding-left: 16px;
      color: var(--text-secondary);
      margin: 16px 0;
    }
    
    /* ----- 价格卡片 ----- */
    .pricing-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
      gap: 24px;
    }
    .pricing-card {
      background: var(--bg-white);
      border: 1px solid var(--border-card);
      border-radius: var(--radius-lg);
      padding: 32px 24px;
      position: relative;
    }
    .pricing-card.recommended {
      border-color: var(--accent-signal);
      box-shadow: 0 0 0 2px rgba(0,180,166,0.2);
    }
    .badge {
      background: var(--warning-amber);
      color: #1a1a1a;
      font-size: 0.8rem;
      font-weight: 600;
      padding: 4px 12px;
      border-radius: 20px;
      position: absolute;
      top: -12px;
      right: 20px;
    }
    .price {
      font-family: var(--font-mono);
      font-size: 2.5rem;
      font-weight: 700;
      color: var(--primary-deep);
    }
    
    /* FAQ 手风琴 */
    .faq-item {
      background: var(--bg-white);
      border-bottom: 1px solid var(--border-light);
    }
    .faq-question {
      padding: 20px 16px;
      font-weight: 600;
      display: flex;
      justify-content: space-between;
      cursor: pointer;
    }
    .faq-answer {
      padding: 0 16px 20px;
      color: var(--text-secondary);
      display: none;
    }
    .faq-item.active .faq-answer {
      display: block;
    }
    
    /* CTA 尾板 */
    .cta-dark {
      background: var(--primary-deep);
      color: white;
      text-align: center;
      padding: 80px 24px;
      border-radius: var(--radius-md);
    }
    
    /* 页脚 */
    .footer {
      background: var(--bg-light);
      padding: 60px 0 30px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 32px;
    }
    @media (max-width: 768px) {
      .hero-grid, .features-grid, .capability-panel, .footer-grid {
        grid-template-columns: 1fr;
      }
      .hero-content h1 {
        font-size: 2rem;
      }
    }