/* roulang page: index */
:root {
      --primary-deep: #1E1E24;
      --primary-darker: #141418;
      --accent-signal: #00E5A0;
      --accent-glow: #1AFFB3;
      --warm-gray: #F4F4F6;
      --alert-orange: #FF6B35;
      --text-main: #1E1E24;
      --text-secondary: #666666;
      --text-light: #AAAAAA;
      --white: #FFFFFF;
      --border-light: #EAEAEC;
      --shadow-sm: 0 2px 12px rgba(0,0,0,0.04);
      --shadow-md: 0 8px 24px rgba(0,0,0,0.08);
      --radius-sm: 6px;
      --radius-md: 8px;
      --radius-lg: 12px;
      --transition: 0.25s ease;
      --font-stack: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Helvetica, Arial, sans-serif;
    }

    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }

    body {
      font-family: var(--font-stack);
      background: var(--white);
      color: var(--text-main);
      line-height: 1.7;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
      scroll-behavior: smooth;
    }

    ::selection {
      background: var(--accent-signal);
      color: var(--primary-darker);
    }

    a {
      color: inherit;
      text-decoration: none;
      transition: color var(--transition), border var(--transition);
    }

    img {
      max-width: 100%;
      height: auto;
      display: block;
    }

    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
    }

    /* 导航栏 */
    .site-header {
      background: var(--primary-darker);
      height: 72px;
      position: sticky;
      top: 0;
      z-index: 50;
      border-bottom: 2px solid var(--accent-signal);
      box-shadow: 0 4px 12px rgba(0,0,0,0.3);
    }

    .header-inner {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 100%;
    }

    .logo {
      font-size: 1.8rem;
      font-weight: 700;
      letter-spacing: -0.5px;
      color: var(--white);
      display: flex;
      align-items: center;
      gap: 8px;
    }
    .logo i {
      color: var(--accent-signal);
      font-size: 2rem;
    }
    .logo span {
      background: linear-gradient(135deg, #FFFFFF 0%, #00E5A0 80%);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
    }

    .nav-links {
      display: flex;
      align-items: center;
      gap: 2rem;
    }

    .nav-links a {
      color: #CCCCCC;
      font-weight: 500;
      font-size: 1rem;
      padding: 0.5rem 0;
      position: relative;
      transition: color var(--transition);
    }

    .nav-links a:hover,
    .nav-links a.active {
      color: var(--accent-signal);
    }

    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: -2px;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--accent-signal);
      box-shadow: 0 0 8px var(--accent-signal);
      transition: width var(--transition);
    }

    .nav-links a:hover::after,
    .nav-links a.active::after {
      width: 100%;
    }

    .cta-btn {
      background: var(--accent-signal);
      color: var(--primary-darker) !important;
      padding: 10px 24px;
      border-radius: var(--radius-sm);
      font-weight: 700;
      transition: all var(--transition);
      border: none;
      cursor: pointer;
      display: inline-block;
      text-align: center;
    }

    .cta-btn:hover {
      background: var(--accent-glow);
      box-shadow: 0 0 16px rgba(0,229,160,0.4);
      color: var(--primary-darker) !important;
    }

    .hamburger {
      display: none;
      color: white;
      font-size: 1.8rem;
      cursor: pointer;
    }

    /* Hero */
    .hero {
      background: var(--primary-darker);
      padding: 80px 0 100px;
      display: flex;
      align-items: center;
      position: relative;
      overflow: hidden;
    }

    .hero-grid {
      display: flex;
      align-items: center;
      gap: 4rem;
    }

    .hero-text {
      flex: 1 1 50%;
    }

    .hero-text h1 {
      font-size: 3.25rem;
      font-weight: 700;
      line-height: 1.15;
      color: white;
      margin-bottom: 1.5rem;
      letter-spacing: -0.5px;
    }

    .hero-text .sub {
      font-size: 1.25rem;
      color: var(--text-light);
      margin-bottom: 2.5rem;
      line-height: 1.6;
    }

    .hero-buttons {
      display: flex;
      gap: 1.25rem;
      flex-wrap: wrap;
    }

    .btn-outline {
      border: 2px solid white;
      background: transparent;
      color: white;
      padding: 12px 32px;
      border-radius: var(--radius-sm);
      font-weight: 600;
      transition: all var(--transition);
    }

    .btn-outline:hover {
      background: white;
      color: var(--primary-darker);
    }

    .hero-image {
      flex: 1 1 45%;
      position: relative;
    }

    .hero-image img {
      border-radius: var(--radius-lg);
      box-shadow: 0 0 40px rgba(0,229,160,0.25);
      width: 100%;
    }

    .data-badge {
      position: absolute;
      bottom: -20px;
      left: -20px;
      background: var(--accent-signal);
      color: var(--primary-darker);
      padding: 16px 28px;
      border-radius: var(--radius-md);
      font-weight: 700;
      font-size: 1.2rem;
      box-shadow: var(--shadow-md);
      display: flex;
      gap: 1rem;
    }

    /* 通用板块 */
    section {
      padding: 100px 0;
    }

    .section-title {
      font-size: 2.25rem;
      font-weight: 700;
      margin-bottom: 1rem;
      color: var(--text-main);
    }

    .section-sub {
      color: var(--text-secondary);
      margin-bottom: 3rem;
      font-size: 1.1rem;
    }

    .bg-light {
      background: var(--warm-gray);
    }

    .bg-dark {
      background: var(--primary-darker);
      color: white;
    }

    /* 产品卡片 */
    .product-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 30px;
    }

    .product-card {
      background: white;
      border-radius: var(--radius-md);
      padding: 32px;
      box-shadow: var(--shadow-sm);
      border: 1px solid var(--border-light);
      transition: all var(--transition);
    }

    .product-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-md);
    }

    .icon-box {
      width: 64px;
      height: 64px;
      background: rgba(0,229,160,0.1);
      border-radius: var(--radius-lg);
      display: flex;
      align-items: center;
      justify-content: center;
      margin-bottom: 24px;
      color: var(--accent-signal);
      font-size: 2rem;
    }

    .product-card h3 {
      font-size: 1.5rem;
      margin-bottom: 12px;
    }

    .product-card p {
      color: #666;
      margin-bottom: 20px;
    }

    .text-link {
      color: var(--accent-signal);
      font-weight: 600;
      display: inline-flex;
      align-items: center;
      gap: 4px;
    }

    .text-link:hover {
      text-decoration: underline;
    }

    /* 场景交替 */
    .scenario-row {
      display: flex;
      align-items: center;
      gap: 3rem;
      margin-bottom: 80px;
    }

    .scenario-row.reverse {
      flex-direction: row-reverse;
    }

    .scenario-img {
      flex: 1 1 50%;
    }

    .scenario-img img {
      border-radius: var(--radius-lg);
      box-shadow: var(--shadow-sm);
    }

    .scenario-content {
      flex: 1 1 50%;
    }

    .tag {
      background: transparent;
      border: 1px solid var(--accent-signal);
      color: var(--accent-signal);
      padding: 4px 16px;
      border-radius: 20px;
      font-size: 0.8rem;
      font-weight: 600;
      display: inline-block;
      margin-bottom: 16px;
    }

    /* 案例卡片 */
    .case-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 30px;
    }

    .case-card {
      background: var(--warm-gray);
      padding: 32px;
      border-radius: var(--radius-md);
    }

    .case-logo {
      font-weight: 700;
      color: #888;
      margin-bottom: 24px;
      filter: grayscale(1);
      transition: var(--transition);
      font-size: 1.3rem;
    }

    .case-card:hover .case-logo {
      filter: grayscale(0);
      color: var(--primary-deep);
    }

    .case-stat {
      font-size: 2.8rem;
      font-weight: 700;
      color: var(--alert-orange);
      line-height: 1.2;
    }

    .case-quote {
      font-style: italic;
      color: #555;
      margin: 16px 0;
    }

    /* FAQ */
    .accordion-item {
      border-bottom: 1px solid var(--border-light);
    }

    .accordion-title {
      background: var(--primary-deep);
      color: white;
      padding: 18px 24px;
      font-weight: 600;
      cursor: pointer;
      transition: background var(--transition);
      display: flex;
      justify-content: space-between;
      align-items: center;
    }

    .accordion-title:hover {
      background: #2A2A32;
    }

    .accordion-content {
      background: #F9F9FA;
      padding: 0 24px;
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease, padding 0.3s;
      color: #444;
    }

    .accordion-item.active .accordion-content {
      padding: 20px 24px;
      max-height: 400px;
      border-left: 3px solid var(--accent-signal);
    }

    /* CTA 尾屏 */
    .cta-dark {
      background: var(--primary-darker);
      text-align: center;
      padding: 100px 0;
    }

    .cta-dark h2 {
      font-size: 2.6rem;
      color: white;
      margin-bottom: 1rem;
    }

    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 2rem;
    }

    .footer-col h4 {
      color: white;
      margin-bottom: 1.2rem;
    }

    .footer-col a, .footer-col p {
      color: #999;
      font-size: 0.95rem;
      display: block;
      margin-bottom: 8px;
    }

    .footer-col a:hover {
      color: var(--accent-signal);
    }

    .qr-placeholder {
      width: 100px;
      height: 100px;
      background: #333;
      display: flex;
      align-items: center;
      justify-content: center;
      color: #aaa;
    }

    @media (max-width: 1024px) {
      .product-grid, .case-grid {
        grid-template-columns: repeat(2, 1fr);
      }
    }

    @media (max-width: 768px) {
      .nav-links {
        display: none;
        flex-direction: column;
        background: var(--primary-darker);
        position: absolute;
        top: 72px;
        left: 0;
        width: 100%;
        padding: 1rem 0;
      }
      .nav-links.open {
        display: flex;
      }
      .hamburger {
        display: block;
      }
      .hero-grid, .scenario-row {
        flex-direction: column;
      }
      .product-grid, .case-grid, .footer-grid {
        grid-template-columns: 1fr;
      }
      h1 {
        font-size: 2.4rem;
      }
    }