/* roulang page: index */
:root {
      --primary: #FF6B35;
      --primary-dark: #E55A2B;
      --primary-light: #FFF0E8;
      --secondary: #1A1A2E;
      --bg: #F5F6FA;
      --card: #FFFFFF;
      --text: #1F2329;
      --text-secondary: #86909C;
      --green: #00B578;
      --orange: #FF9F0A;
      --blue: #4E6EF2;
      --border: #E5E6EB;
      --shadow-sm: 0 2px 12px rgba(0,0,0,0.06);
      --shadow-md: 0 8px 24px rgba(0,0,0,0.10);
      --shadow-nav: 0 1px 4px rgba(0,0,0,0.04);
      --radius-sm: 6px;
      --radius: 8px;
      --radius-md: 12px;
      --radius-lg: 16px;
      --radius-xl: 50px;
      --font-stack: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      --max-width: 1200px;
      --transition: 200ms ease-out;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    html {
      scroll-behavior: smooth;
      font-size: 16px;
    }
    body {
      font-family: var(--font-stack);
      background: var(--bg);
      color: var(--text);
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
    }
    .container {
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 32px;
    }
    a {
      text-decoration: none;
      color: inherit;
      transition: color var(--transition);
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
      border-radius: var(--radius-md);
    }
    button, .btn {
      cursor: pointer;
      font-family: var(--font-stack);
      border: none;
      outline: none;
      transition: all var(--transition);
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      font-weight: 600;
    }
    h1, h2, h3, h4 {
      font-weight: 700;
      line-height: 1.3;
    }
    ul {
      list-style: none;
    }
    /* 导航 */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      right: 0;
      height: 64px;
      background: #fff;
      z-index: 1000;
      box-shadow: var(--shadow-nav);
      border-bottom: 1px solid #f0f0f0;
      transition: box-shadow var(--transition);
    }
    .header.scrolled {
      box-shadow: var(--shadow-sm);
    }
    .nav {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 100%;
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 32px;
    }
    .logo {
      font-size: 22px;
      font-weight: 700;
      color: var(--primary);
      display: flex;
      align-items: center;
      gap: 6px;
      letter-spacing: 0.5px;
    }
    .logo span {
      display: inline-block;
      width: 28px;
      height: 28px;
      background: var(--primary);
      border-radius: 8px;
      position: relative;
      overflow: hidden;
    }
    .logo span::after {
      content: '';
      position: absolute;
      width: 12px;
      height: 12px;
      background: #fff;
      border-radius: 50%;
      top: 50%;
      left: 50%;
      transform: translate(-50%, -50%);
    }
    .nav-menu {
      display: flex;
      align-items: center;
      gap: 32px;
    }
    .nav-link {
      font-size: 15px;
      font-weight: 500;
      color: var(--text);
      padding: 4px 0;
      position: relative;
    }
    .nav-link:hover, .nav-link.active {
      color: var(--primary);
    }
    .nav-link.active::after {
      content: '';
      position: absolute;
      bottom: -4px;
      left: 0;
      width: 100%;
      height: 2px;
      background: var(--primary);
      border-radius: 2px;
    }
    .btn-primary {
      background: var(--primary);
      color: #fff;
      padding: 12px 28px;
      border-radius: var(--radius);
      font-size: 15px;
      font-weight: 600;
      box-shadow: 0 2px 8px rgba(255,107,53,0.25);
    }
    .btn-primary:hover {
      background: var(--primary-dark);
      transform: translateY(-1px);
      box-shadow: 0 6px 16px rgba(255,107,53,0.35);
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 6px;
      cursor: pointer;
      z-index: 1001;
      background: transparent;
      border: none;
      padding: 8px;
    }
    .hamburger span {
      display: block;
      width: 24px;
      height: 2px;
      background: var(--text);
      border-radius: 2px;
      transition: var(--transition);
    }
    .mobile-menu {
      display: none;
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 100vh;
      background: #fff;
      z-index: 999;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      gap: 28px;
      opacity: 0;
      pointer-events: none;
      transition: opacity 250ms ease;
    }
    .mobile-menu.active {
      opacity: 1;
      pointer-events: auto;
    }
    .mobile-menu .nav-link {
      font-size: 20px;
      font-weight: 600;
    }
    /* Hero */
    .hero {
      padding: 140px 0 80px;
      background: #fff;
    }
    .hero .container {
      display: flex;
      align-items: center;
      gap: 60px;
    }
    .hero-content {
      flex: 1;
    }
    .hero h1 {
      font-size: 44px;
      font-weight: 800;
      color: var(--secondary);
      margin-bottom: 20px;
      line-height: 1.2;
    }
    .hero .subtitle {
      font-size: 18px;
      color: var(--text-secondary);
      margin-bottom: 32px;
      max-width: 480px;
    }
    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .btn-outline {
      background: transparent;
      border: 1.5px solid var(--primary);
      color: var(--primary);
      padding: 12px 28px;
      border-radius: var(--radius);
      font-size: 15px;
      font-weight: 600;
    }
    .btn-outline:hover {
      background: var(--primary-light);
    }
    .hero-img {
      flex: 1;
      background: url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      min-height: 380px;
      border-radius: var(--radius-lg);
      position: relative;
      overflow: hidden;
    }
    .hero-img::before {
      content: '';
      position: absolute;
      inset: 0;
      background: linear-gradient(135deg, rgba(255,107,53,0.05) 0%, rgba(26,26,46,0.1) 100%);
    }
    /* 通用区块 */
    section {
      padding: 80px 0;
    }
    .section-title {
      font-size: 32px;
      font-weight: 700;
      text-align: center;
      margin-bottom: 16px;
      color: var(--secondary);
    }
    .section-desc {
      text-align: center;
      color: var(--text-secondary);
      max-width: 640px;
      margin: 0 auto 48px;
      font-size: 17px;
    }
    /* 优势卡片 */
    .grid-4 {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
    }
    .feature-card {
      background: var(--card);
      border-radius: var(--radius-lg);
      padding: 32px 24px;
      box-shadow: var(--shadow-sm);
      transition: all var(--transition);
      text-align: left;
    }
    .feature-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-md);
    }
    .feature-icon {
      font-size: 28px;
      color: var(--primary);
      margin-bottom: 16px;
      display: inline-block;
    }
    .feature-card h3 {
      font-size: 20px;
      margin-bottom: 10px;
      font-weight: 600;
    }
    .feature-card p {
      color: var(--text-secondary);
      font-size: 15px;
      margin-bottom: 16px;
    }
    .badge {
      display: inline-block;
      background: var(--primary);
      color: #fff;
      padding: 6px 14px;
      border-radius: var(--radius-sm);
      font-weight: 700;
      font-size: 18px;
      letter-spacing: 0.3px;
    }
    /* 产品交替区 */
    .product-row {
      display: flex;
      align-items: center;
      gap: 60px;
      margin-bottom: 80px;
    }
    .product-row.reverse {
      flex-direction: row-reverse;
    }
    .product-img {
      flex: 1;
      background: #eef0f5;
      border-radius: var(--radius-md);
      overflow: hidden;
    }
    .product-img img {
      width: 100%;
      height: 320px;
      object-fit: cover;
    }
    .product-text {
      flex: 1;
    }
    .product-text h3 {
      font-size: 26px;
      margin-bottom: 16px;
      color: var(--secondary);
    }
    .product-text p {
      color: var(--text-secondary);
      margin-bottom: 20px;
    }
    .check-list {
      display: flex;
      flex-direction: column;
      gap: 12px;
    }
    .check-list li {
      display: flex;
      align-items: center;
      gap: 10px;
      font-weight: 500;
    }
    .check-list li::before {
      content: '✓';
      color: var(--primary);
      font-weight: 700;
      font-size: 18px;
    }
    /* 场景卡片 */
    .grid-3 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .scenario-card {
      background: var(--card);
      border-radius: var(--radius-lg);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
      transition: all var(--transition);
    }
    .scenario-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-md);
    }
    .scenario-img {
      height: 200px;
      background-size: cover;
      background-position: center;
    }
    .scenario-body {
      padding: 24px;
    }
    .scenario-body h3 {
      font-size: 20px;
      margin-bottom: 10px;
    }
    /* 案例区 */
    .cases-grid {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 24px;
    }
    .case-card {
      background: var(--card);
      border-radius: var(--radius-lg);
      padding: 28px;
      display: flex;
      gap: 24px;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
    }
    .case-card:hover {
      box-shadow: var(--shadow-md);
    }
    .case-badge {
      background: linear-gradient(180deg, #FF6B35 0%, #E55A2B 100%);
      color: #fff;
      padding: 12px 18px;
      border-radius: var(--radius-sm);
      font-weight: 800;
      font-size: 28px;
      white-space: nowrap;
      align-self: flex-start;
    }
    /* FAQ */
    .faq-item {
      background: var(--card);
      border-radius: var(--radius);
      margin-bottom: 12px;
      overflow: hidden;
      transition: all 150ms;
    }
    .faq-question {
      padding: 20px 24px;
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-weight: 600;
      cursor: pointer;
      background: #fff;
      border: none;
      width: 100%;
      text-align: left;
      font-size: 16px;
    }
    .faq-icon {
      font-size: 22px;
      color: var(--primary);
      transition: transform 150ms;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 250ms ease;
      background: #FAFBFC;
      padding: 0 24px;
    }
    .faq-answer p {
      padding: 16px 0;
      color: var(--text-secondary);
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
    }
    .faq-item.active .faq-icon {
      transform: rotate(45deg);
    }
    /* CTA */
    .cta-section {
      background: linear-gradient(135deg, #FF6B35 0%, #FF8C42 100%);
      padding: 80px 0;
      text-align: center;
    }
    .cta-title {
      font-size: 34px;
      font-weight: 700;
      color: #fff;
      margin-bottom: 16px;
    }
    .cta-sub {
      color: rgba(255,255,255,0.85);
      font-size: 17px;
      margin-bottom: 32px;
    }
    .btn-white-outline {
      background: transparent;
      border: 2px solid #fff;
      color: #fff;
      padding: 16px 40px;
      border-radius: var(--radius-xl);
      font-size: 18px;
      font-weight: 700;
    }
    .btn-white-outline:hover {
      background: #fff;
      color: var(--primary);
    }
    /* Footer */
    .footer {
      background: var(--secondary);
      color: #86909C;
      padding: 50px 0 30px;
    }
    .footer-grid {
      display: flex;
      justify-content: space-between;
      flex-wrap: wrap;
      gap: 40px;
      margin-bottom: 40px;
    }
    .footer-logo {
      font-size: 22px;
      font-weight: 700;
      color: #fff;
    }
    .footer-links {
      display: flex;
      gap: 60px;
      flex-wrap: wrap;
    }
    .footer-col h4 {
      color: #fff;
      margin-bottom: 16px;
      font-weight: 600;
    }
    .footer-col a {
      display: block;
      color: #86909C;
      margin-bottom: 10px;
      font-size: 14px;
    }
    .footer-col a:hover {
      color: var(--primary);
    }
    .copyright {
      border-top: 1px solid rgba(255,255,255,0.08);
      padding-top: 24px;
      text-align: center;
      font-size: 14px;
    }
    /* 响应式 */
    @media (max-width: 1024px) {
      .grid-4 { grid-template-columns: repeat(2, 1fr); }
      .grid-3 { grid-template-columns: repeat(2, 1fr); }
      .hero .container { flex-direction: column; }
      .hero h1 { font-size: 36px; }
    }
    @media (max-width: 768px) {
      .container { padding: 0 20px; }
      .nav-menu { display: none; }
      .hamburger { display: flex; }
      .mobile-menu { display: flex; }
      .grid-4, .grid-3 { grid-template-columns: 1fr; }
      .product-row, .product-row.reverse { flex-direction: column; }
      .cases-grid { grid-template-columns: 1fr; }
      .footer-grid { flex-direction: column; }
      .hero h1 { font-size: 30px; }
      section { padding: 60px 0; }
      .section-title { font-size: 26px; }
    }