/* roulang page: index */
:root {
      --primary-dark: #1B2A1E;
      --accent-electric: #00E676;
      --accent-hover: #00C853;
      --bg-warm: #F7F6F3;
      --card-white: #FFFFFF;
      --panel-light: #E8F5E9;
      --border-soft: #E5E3DE;
      --text-main: #1B2A1E;
      --text-muted: #5A6B5E;
      --font-cn: "PingFang SC", "Microsoft YaHei", "Noto Sans SC", sans-serif;
      --font-en: "Inter", "SF Pro Display", system-ui, -apple-system, sans-serif;
      --font-num: "DIN Alternate", "Oswald", "Inter", sans-serif;
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-tag: 6px;
      --shadow-card: 0 1px 3px rgba(0,0,0,0.04), 0 1px 2px rgba(0,0,0,0.06);
      --shadow-card-hover: 0 20px 35px rgba(0,0,0,0.08), 0 8px 15px rgba(0,0,0,0.04);
      --transition-smooth: 300ms ease-out;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    body {
      font-family: var(--font-cn);
      background-color: var(--bg-warm);
      color: var(--text-main);
      line-height: 1.5;
      -webkit-font-smoothing: antialiased;
    }
    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 24px;
    }
    @media (min-width: 768px) {
      .container { padding: 0 40px; }
    }
    /* 导航 */
    .navbar {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 1000;
      padding: 16px 32px;
      display: flex;
      align-items: center;
      justify-content: space-between;
      transition: background var(--transition-smooth), backdrop-filter var(--transition-smooth);
      background: transparent;
    }
    .navbar.scrolled {
      background: rgba(27,42,30,0.92);
      backdrop-filter: blur(20px);
    }
    .logo {
      display: flex;
      align-items: center;
      gap: 8px;
      font-size: 24px;
      font-weight: 700;
      color: white;
      text-decoration: none;
      letter-spacing: -0.5px;
    }
    .logo-icon {
      display: inline-block;
      width: 36px;
      height: 36px;
      background: var(--accent-electric);
      border-radius: 50%;
      position: relative;
      mask: radial-gradient(circle at 30% 30%, white 20%, transparent 21%);
      -webkit-mask: radial-gradient(circle at 30% 30%, white 20%, transparent 21%);
      background: linear-gradient(135deg, #00E676, #1B2A1E);
      border: 2px solid var(--accent-electric);
    }
    .nav-links {
      display: flex;
      gap: 32px;
      list-style: none;
    }
    .nav-links a {
      color: rgba(255,255,255,0.9);
      text-decoration: none;
      font-weight: 500;
      font-size: 16px;
      transition: color 0.2s;
    }
    .nav-links a:hover {
      color: var(--accent-electric);
    }
    .nav-cta {
      background: var(--accent-electric);
      color: var(--primary-dark) !important;
      padding: 12px 28px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      transition: background 0.2s, transform 0.2s;
      text-decoration: none;
      display: inline-block;
    }
    .nav-cta:hover {
      background: var(--accent-hover);
      transform: translateY(-2px);
      box-shadow: 0 8px 18px rgba(0,230,118,0.3);
    }
    .hamburger {
      display: none;
      font-size: 28px;
      color: white;
      background: none;
      border: none;
      cursor: pointer;
    }
    @media (max-width: 768px) {
      .nav-links, .nav-cta-desktop {
        display: none;
      }
      .hamburger {
        display: block;
      }
      .navbar {
        padding: 16px 24px;
      }
    }
    .mobile-menu {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 100vh;
      background: var(--primary-dark);
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      gap: 32px;
      list-style: none;
      transform: translateY(-100%);
      transition: transform 0.3s ease;
      z-index: 999;
    }
    .mobile-menu.active {
      transform: translateY(0);
    }
    .mobile-menu a {
      color: white;
      font-size: 22px;
      text-decoration: none;
      font-weight: 600;
    }
    /* 首屏 */
    .hero {
      background: var(--primary-dark);
      position: relative;
      overflow: hidden;
      min-height: 100vh;
      display: flex;
      align-items: center;
      color: white;
      padding: 120px 0 80px;
    }
    .hero-bg-lines {
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background: radial-gradient(circle at 20% 30%, rgba(0,230,118,0.15) 0%, transparent 40%);
      pointer-events: none;
    }
    .hero-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 60px;
      align-items: center;
    }
    .hero h1 {
      font-size: 48px;
      line-height: 1.2;
      font-weight: 700;
      letter-spacing: -0.5px;
      margin-bottom: 20px;
    }
    .hero .subtitle {
      font-size: 18px;
      opacity: 0.85;
      margin-bottom: 32px;
    }
    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
      margin-bottom: 40px;
    }
    .btn-primary {
      background: var(--accent-electric);
      color: var(--primary-dark);
      padding: 16px 36px;
      border-radius: var(--radius-btn);
      font-weight: 700;
      text-decoration: none;
      transition: 0.2s;
      border: none;
      cursor: pointer;
    }
    .btn-primary:hover {
      background: var(--accent-hover);
      transform: translateY(-2px);
    }
    .btn-ghost {
      background: transparent;
      border: 1.5px solid white;
      color: white;
      padding: 16px 36px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      text-decoration: none;
      transition: 0.2s;
    }
    .btn-ghost:hover {
      background: rgba(255,255,255,0.1);
    }
    .hero-stats {
      display: flex;
      gap: 32px;
      flex-wrap: wrap;
    }
    .stat-item {
      font-family: var(--font-num);
    }
    .stat-number {
      font-size: 28px;
      font-weight: 700;
      color: var(--accent-electric);
    }
    .hero-image {
      background: url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      border-radius: var(--radius-card);
      height: 400px;
      box-shadow: 0 20px 40px rgba(0,0,0,0.3);
      position: relative;
    }
    @media (max-width: 768px) {
      .hero-grid {
        grid-template-columns: 1fr;
      }
      .hero h1 {
        font-size: 36px;
      }
      .hero-image {
        height: 280px;
      }
    }
    /* 板块通用 */
    section {
      padding: 80px 0;
    }
    .section-title {
      font-size: 36px;
      font-weight: 700;
      text-align: center;
      margin-bottom: 16px;
    }
    .section-sub {
      text-align: center;
      color: var(--text-muted);
      margin-bottom: 48px;
    }
    /* 信任条 */
    .trust-bar {
      display: flex;
      justify-content: space-around;
      flex-wrap: wrap;
      gap: 24px;
      padding: 40px 0;
      background: white;
      filter: grayscale(1);
      opacity: 0.8;
    }
    /* 产品卡片 */
    .product-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 32px;
    }
    .product-card {
      background: var(--card-white);
      border-radius: var(--radius-card);
      padding: 32px;
      box-shadow: var(--shadow-card);
      transition: var(--transition-smooth);
      border: 1px solid transparent;
    }
    .product-card.featured {
      border-top: 4px solid var(--accent-electric);
      box-shadow: var(--shadow-card-hover);
    }
    .product-card:hover {
      transform: translateY(-8px);
      box-shadow: var(--shadow-card-hover);
      border-color: var(--accent-electric);
    }
    .product-icon {
      font-size: 48px;
      color: var(--accent-electric);
      margin-bottom: 16px;
    }
    @media (max-width: 1024px) {
      .product-grid { grid-template-columns: 1fr 1fr; }
    }
    @media (max-width: 640px) {
      .product-grid { grid-template-columns: 1fr; }
    }
    /* 场景 */
    .scene-row {
      display: flex;
      align-items: center;
      gap: 48px;
      margin-bottom: 64px;
    }
    .scene-img {
      flex: 1;
      border-radius: var(--radius-card);
      height: 300px;
      background-size: cover;
      background-position: center;
    }
    .scene-text {
      flex: 1;
    }
    @media (max-width: 768px) {
      .scene-row {
        flex-direction: column;
      }
    }
    /* 技术优势 */
    .tech-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
    }
    .tech-item {
      background: var(--panel-light);
      padding: 32px;
      border-radius: var(--radius-card);
      text-align: center;
    }
    @media (max-width: 1024px) { .tech-grid { grid-template-columns: 1fr 1fr; } }
    /* 案例 */
    .case-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .case-card {
      border-radius: var(--radius-card);
      overflow: hidden;
      position: relative;
      background: #1B2A1E;
    }
    .case-img {
      height: 240px;
      background-size: cover;
      transition: transform 0.3s;
    }
    .case-card:hover .case-img {
      transform: scale(1.03);
    }
    .case-overlay {
      position: absolute;
      bottom: 0;
      left: 0;
      right: 0;
      padding: 24px;
      background: linear-gradient(transparent, rgba(0,0,0,0.8));
      color: white;
    }
    /* FAQ */
    .faq-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 16px;
    }
    .faq-item {
      background: white;
      border-radius: var(--radius-card);
      padding: 20px;
      border-left: 4px solid var(--accent-electric);
      cursor: pointer;
    }
    .faq-answer {
      display: none;
      margin-top: 12px;
      color: var(--text-muted);
    }
    .faq-item.active .faq-answer {
      display: block;
    }
    @media (max-width: 768px) { .faq-grid { grid-template-columns: 1fr; } }
    /* CTA */
    .cta-banner {
      background: var(--primary-dark);
      text-align: center;
      padding: 80px 24px;
      color: white;
    }
    /* 页脚 */
    .footer {
      background: #1B2A1E;
      color: #ccc;
      padding: 60px 0 20px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 32px;
    }
    @media (max-width: 768px) {
      .footer-grid { grid-template-columns: 1fr; }
    }