/* roulang page: index */
:root {
      --primary: #E8452D;
      --primary-hover: #C53020;
      --secondary: #1E1E1E;
      --accent: #FFC107;
      --gray-light: #F5F5F7;
      --gray-mid: #E5E5E7;
      --text-dark: #1E1E1E;
      --text-body: #333333;
      --text-muted: #666666;
      --white: #FFFFFF;
      --bg-section: #F9F9FB;
      --shadow-sm: 0 4px 12px rgba(0, 0, 0, 0.06);
      --shadow-hover: 0 12px 24px rgba(0, 0, 0, 0.12);
      --radius-md: 12px;
      --radius-lg: 16px;
      --radius-btn: 10px;
      --transition: 0.25s ease;
      --font-stack: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      --container-max: 1200px;
    }

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

    body {
      font-family: var(--font-stack);
      background-color: var(--white);
      color: var(--text-body);
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
      scroll-behavior: smooth;
    }

    .container {
      max-width: var(--container-max);
      margin: 0 auto;
      padding: 0 24px;
    }

    h1, h2, h3, h4 {
      font-weight: 700;
      line-height: 1.2;
      color: var(--text-dark);
    }

    h1 {
      font-size: clamp(2.4rem, 6vw, 3.8rem);
      font-weight: 800;
      letter-spacing: -0.5px;
    }

    h2 {
      font-size: clamp(1.8rem, 4vw, 2.6rem);
      margin-bottom: 1.5rem;
      position: relative;
      display: inline-block;
    }

    .section-title {
      text-align: center;
      margin-bottom: 3rem;
      width: 100%;
    }

    .section-title h2 {
      margin-bottom: 0.5rem;
    }

    .section-title .subtitle {
      font-size: 1.1rem;
      color: var(--text-muted);
      font-weight: 400;
    }

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

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

    button, .btn {
      cursor: pointer;
      font-family: inherit;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      font-weight: 600;
      transition: var(--transition);
      border: none;
      outline: none;
    }

    /* 导航栏 */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 1000;
      padding: 16px 0;
      transition: background 0.3s, box-shadow 0.3s;
      background: transparent;
    }

    .header.scrolled {
      background: rgba(255, 255, 255, 0.96);
      backdrop-filter: blur(8px);
      box-shadow: 0 4px 20px rgba(0,0,0,0.06);
    }

    .header .container {
      display: flex;
      align-items: center;
      justify-content: space-between;
    }

    .logo {
      font-size: 1.8rem;
      font-weight: 800;
      color: #fff;
      letter-spacing: 1px;
      display: flex;
      align-items: center;
      gap: 6px;
      transition: color 0.3s;
    }

    .header.scrolled .logo {
      color: var(--text-dark);
    }

    .logo-icon {
      width: 32px;
      height: 32px;
      background: var(--primary);
      mask: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" fill="currentColor"><path d="M13.5 2.5v6h6l-8 12v-6h-6l8-12z"/></svg>') center/contain no-repeat;
      background-color: currentColor;
      display: inline-block;
    }

    .nav-menu {
      display: flex;
      align-items: center;
      gap: 32px;
    }

    .nav-link {
      font-weight: 500;
      color: rgba(255,255,255,0.9);
      font-size: 1rem;
      position: relative;
      padding: 4px 0;
    }

    .header.scrolled .nav-link {
      color: var(--text-dark);
    }

    .nav-link::after {
      content: '';
      position: absolute;
      bottom: -4px;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--primary);
      transition: width 0.2s;
    }

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

    .btn-primary {
      background: var(--primary);
      color: white;
      padding: 12px 28px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      box-shadow: 0 6px 18px rgba(232,69,45,0.3);
    }

    .btn-primary:hover {
      background: var(--primary-hover);
      box-shadow: 0 10px 24px rgba(232,69,45,0.4);
      transform: translateY(-1px);
    }

    .btn-outline {
      background: transparent;
      border: 2px solid var(--primary);
      color: var(--primary);
      padding: 12px 28px;
      border-radius: var(--radius-btn);
      font-weight: 600;
    }

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

    .btn-white {
      background: white;
      color: var(--primary);
      padding: 14px 36px;
      border-radius: var(--radius-btn);
      font-weight: 700;
    }

    .btn-white:hover {
      background: #f0f0f0;
      box-shadow: 0 8px 20px rgba(0,0,0,0.15);
    }

    .mobile-toggle {
      display: none;
      background: none;
      border: none;
      color: white;
      font-size: 2rem;
      line-height: 1;
    }

    .header.scrolled .mobile-toggle {
      color: var(--text-dark);
    }

    /* Hero */
    .hero {
      min-height: 100vh;
      background: url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      position: relative;
      display: flex;
      align-items: center;
      color: white;
    }

    .hero::before {
      content: '';
      position: absolute;
      inset: 0;
      background: linear-gradient(135deg, rgba(0,0,0,0.75) 0%, rgba(30,30,30,0.6) 100%);
      z-index: 1;
    }

    .hero .container {
      position: relative;
      z-index: 2;
      display: flex;
      flex-direction: column;
      align-items: flex-start;
      max-width: 700px;
    }

    .hero h1 {
      color: white;
      margin-bottom: 1.2rem;
      text-shadow: 0 4px 20px rgba(0,0,0,0.4);
    }

    .hero .hero-sub {
      font-size: 1.25rem;
      color: rgba(255,255,255,0.9);
      margin-bottom: 2.5rem;
      line-height: 1.6;
    }

    .hero-actions {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }

    /* 区块通用 */
    section {
      padding: 5rem 0;
    }

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

    /* 优势 非对称网格 */
    .features-grid {
      display: grid;
      grid-template-columns: 1.2fr 0.8fr;
      gap: 28px;
      margin-top: 2rem;
    }

    .feature-card {
      background: white;
      border-radius: var(--radius-lg);
      padding: 2rem;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
      display: flex;
      flex-direction: column;
      gap: 1rem;
    }

    .feature-card:first-child {
      grid-row: span 2;
    }

    .feature-card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-hover);
    }

    .feature-icon {
      width: 48px;
      height: 48px;
      background: rgba(232,69,45,0.1);
      border-radius: 12px;
      display: flex;
      align-items: center;
      justify-content: center;
      color: var(--primary);
      font-size: 1.6rem;
    }

    .feature-card h3 {
      font-size: 1.4rem;
    }

    /* 服务网格 */
    .services-grid {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 28px;
      margin-top: 2rem;
    }

    .service-card {
      background: white;
      border-radius: var(--radius-lg);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
    }

    .service-card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-hover);
    }

    .service-img {
      height: 200px;
      background-size: cover;
      background-position: center;
      transition: transform 0.4s;
    }

    .service-card:hover .service-img {
      transform: scale(1.04);
    }

    .service-body {
      padding: 1.5rem;
    }

    .service-body h4 {
      margin-bottom: 0.5rem;
    }

    /* 案例数据 */
    .stats-grid {
      display: flex;
      justify-content: space-around;
      flex-wrap: wrap;
      gap: 24px;
      margin-top: 2rem;
    }

    .stat-item {
      text-align: center;
    }

    .stat-number {
      font-size: 3rem;
      font-weight: 800;
      color: var(--primary);
      line-height: 1;
    }

    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 2rem auto 0;
    }

    .faq-item {
      background: white;
      border-radius: var(--radius-md);
      margin-bottom: 16px;
      box-shadow: 0 2px 8px rgba(0,0,0,0.04);
      overflow: hidden;
    }

    .faq-question {
      width: 100%;
      background: transparent;
      border: none;
      padding: 1.4rem 2rem;
      font-weight: 700;
      font-size: 1.1rem;
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
      color: var(--text-dark);
    }

    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s ease, padding 0.3s;
      padding: 0 2rem;
      color: var(--text-body);
    }

    .faq-item.active .faq-answer {
      max-height: 200px;
      padding: 0 2rem 1.4rem;
    }

    .faq-icon {
      transition: transform 0.3s;
    }

    .faq-item.active .faq-icon {
      transform: rotate(45deg);
    }

    /* CTA */
    .cta-section {
      background: linear-gradient(135deg, #E8452D 0%, #C53020 100%);
      color: white;
      text-align: center;
    }

    .cta-section h2 {
      color: white;
    }

    /* Footer */
    .footer {
      background: var(--secondary);
      color: #ccc;
      padding: 3rem 0 1.5rem;
    }

    .footer-grid {
      display: flex;
      justify-content: space-between;
      flex-wrap: wrap;
      gap: 40px;
      margin-bottom: 2rem;
    }

    .footer-brand p {
      max-width: 260px;
      margin: 1rem 0;
    }

    .footer-links a {
      display: block;
      margin-bottom: 10px;
      color: #aaa;
    }

    .footer-links a:hover {
      color: var(--primary);
    }

    .copyright {
      border-top: 1px solid #333;
      padding-top: 1.5rem;
      text-align: center;
      font-size: 0.9rem;
    }

    @media (max-width: 1024px) {
      .features-grid {
        grid-template-columns: 1fr;
      }
      .services-grid {
        grid-template-columns: 1fr;
      }
    }

    @media (max-width: 768px) {
      .nav-menu {
        display: none;
      }
      .mobile-toggle {
        display: block;
      }
      .hero h1 {
        font-size: 2.2rem;
      }
      .stats-grid {
        flex-direction: column;
        align-items: center;
      }
    }

    .mobile-menu {
      position: fixed;
      top: 0;
      right: -100%;
      width: 80%;
      max-width: 320px;
      height: 100vh;
      background: white;
      box-shadow: -10px 0 30px rgba(0,0,0,0.1);
      z-index: 2000;
      transition: right 0.3s;
      padding: 2rem;
      display: flex;
      flex-direction: column;
      gap: 24px;
    }

    .mobile-menu.active {
      right: 0;
    }