/* roulang page: index */
:root {
      --primary: #0B3D2E;
      --primary-hover: #073525;
      --accent: #F5A623;
      --accent-light: #F7B84E;
      --bg-light: #FAFBF7;
      --bg-dark: #0A1F1A;
      --text-primary: #2C3E33;
      --text-secondary: #6B7B73;
      --text-on-dark: #FFFFFF;
      --border-card: rgba(11,61,46,0.08);
      --shadow-card: 0 2px 12px rgba(11,61,46,0.06);
      --shadow-hover: 0 8px 28px rgba(11,61,46,0.12);
      --radius-card: 12px;
      --radius-btn: 8px;
      --font-sans: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", "Noto Sans SC", sans-serif;
      --font-number: "Inter", "SF Pro Display", system-ui;
      --max-width: 1280px;
      --nav-height: 64px;
    }

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

    body {
      font-family: var(--font-sans);
      background-color: var(--bg-light);
      color: var(--text-primary);
      line-height: 1.75;
      -webkit-font-smoothing: antialiased;
      scroll-behavior: smooth;
    }

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

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

    a {
      text-decoration: none;
      color: inherit;
      transition: color 0.2s ease, background-color 0.2s ease;
    }

    button, .btn {
      font-family: var(--font-sans);
      cursor: pointer;
      border: none;
      background: none;
      font-weight: 600;
      transition: all 0.2s ease;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      border-radius: var(--radius-btn);
    }

    h1, h2, h3 {
      font-weight: 700;
      line-height: 1.3;
    }

    h2 {
      font-size: 2.25rem;
      letter-spacing: -0.02em;
      margin-bottom: 1rem;
    }

    .section {
      padding: 5rem 0;
    }

    /* 导航 */
    #nav {
      position: sticky;
      top: 0;
      background: white;
      height: var(--nav-height);
      display: flex;
      align-items: center;
      z-index: 50;
      border-bottom: 1px solid rgba(11,61,46,0.08);
      backdrop-filter: blur(8px);
      background-color: rgba(255,255,255,0.92);
    }

    .nav-container {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
    }

    .logo {
      font-weight: 700;
      font-size: 1.5rem;
      color: var(--primary);
      display: flex;
      align-items: baseline;
      gap: 6px;
      letter-spacing: -0.3px;
    }
    .logo small {
      font-size: 0.75rem;
      font-weight: 400;
      color: var(--text-secondary);
      margin-left: 4px;
    }

    .nav-links {
      display: flex;
      align-items: center;
      gap: 2rem;
    }
    .nav-links a {
      font-size: 0.9rem;
      color: var(--text-primary);
      font-weight: 500;
      padding: 0.5rem 0;
      border-bottom: 2px solid transparent;
    }
    .nav-links a:hover {
      color: var(--primary);
      border-bottom-color: var(--primary);
    }

    .btn-primary {
      background-color: var(--primary);
      color: white;
      padding: 0.7rem 1.8rem;
      font-size: 0.9rem;
    }
    .btn-primary:hover {
      background-color: var(--primary-hover);
      transform: scale(1.03);
    }

    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
    }
    .hamburger span {
      width: 24px;
      height: 2px;
      background: var(--primary);
      transition: 0.2s;
      display: block;
      border-radius: 2px;
    }

    /* Hero */
    #hero {
      background-color: var(--bg-light);
      display: flex;
      align-items: center;
      min-height: 85vh;
      padding-top: var(--nav-height);
    }
    .hero-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 3rem;
      align-items: center;
    }
    .hero-text h1 {
      font-size: 3rem;
      font-weight: 700;
      color: var(--primary);
      margin-bottom: 1.2rem;
    }
    .hero-text p {
      font-size: 1.1rem;
      color: var(--text-secondary);
      margin-bottom: 2rem;
      max-width: 90%;
    }
    .hero-image img {
      border-radius: 24px;
      box-shadow: var(--shadow-hover);
      width: 100%;
      aspect-ratio: 4/3;
      object-fit: cover;
    }

    .btn-accent {
      background-color: var(--accent);
      color: #0A1F1A;
      padding: 0.9rem 2.2rem;
      font-size: 1rem;
      font-weight: 700;
    }
    .btn-accent:hover {
      background-color: var(--accent-light);
      transform: scale(1.03);
    }
    .btn-outline {
      border: 2px solid var(--primary);
      color: var(--primary);
      background: transparent;
      padding: 0.7rem 2rem;
    }
    .btn-outline:hover {
      background: var(--primary);
      color: white;
    }

    /* 优势 */
    .features-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 1.8rem;
      margin-top: 2.5rem;
    }
    .feature-card {
      background: white;
      border-radius: var(--radius-card);
      padding: 2rem 1.5rem;
      text-align: center;
      box-shadow: var(--shadow-card);
      border: 1px solid var(--border-card);
      transition: all 0.25s;
    }
    .feature-card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-hover);
    }
    .feature-icon {
      font-size: 2.2rem;
      color: var(--primary);
      margin-bottom: 1.2rem;
    }
    .feature-card h3 {
      font-size: 1.25rem;
      margin-bottom: 0.7rem;
    }

    /* 数据 */
    #stats {
      background-color: var(--primary);
      color: white;
    }
    .stats-grid {
      display: flex;
      justify-content: space-around;
      text-align: center;
      flex-wrap: wrap;
    }
    .stat-item {
      padding: 1rem;
    }
    .stat-number {
      font-family: var(--font-number);
      font-size: 3.2rem;
      font-weight: 700;
      color: var(--accent);
      line-height: 1.2;
    }
    .stat-label {
      font-size: 0.95rem;
      opacity: 0.8;
      margin-top: 0.5rem;
    }
    .stat-divider {
      width: 1px;
      background: rgba(255,255,255,0.2);
    }

    /* 服务矩阵 */
    .services-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 2rem;
      margin-top: 2.5rem;
    }
    .service-card {
      background: white;
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-card);
      border: 1px solid var(--border-card);
      transition: 0.25s;
      display: flex;
      flex-direction: column;
    }
    .service-card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-hover);
    }
    .service-img {
      height: 180px;
      object-fit: cover;
    }
    .service-content {
      padding: 1.5rem;
      display: flex;
      flex-direction: column;
      flex: 1;
    }
    .service-content h3 {
      font-size: 1.2rem;
      margin-bottom: 0.6rem;
    }
    .service-link {
      margin-top: auto;
      color: var(--primary);
      font-weight: 600;
      font-size: 0.9rem;
    }

    /* 案例 */
    .cases-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 2rem;
      margin-top: 2rem;
    }
    .case-card {
      background: white;
      border-radius: var(--radius-card);
      padding: 1.5rem;
      box-shadow: var(--shadow-card);
      border: 1px solid var(--border-card);
    }
    .case-img {
      border-radius: 8px;
      height: 140px;
      object-fit: cover;
      margin-bottom: 1rem;
    }
    .case-quote {
      font-style: italic;
      color: var(--text-primary);
      margin-bottom: 0.8rem;
    }

    /* FAQ */
    .faq-list {
      max-width: 720px;
      margin: 2rem auto 0;
    }
    .faq-item {
      border-bottom: 1px solid var(--border-card);
    }
    .faq-question {
      background: var(--bg-light);
      padding: 1.2rem 1.5rem;
      font-weight: 600;
      display: flex;
      justify-content: space-between;
      cursor: pointer;
      transition: background 0.2s;
    }
    .faq-question:hover {
      background: #eef2ed;
    }
    .faq-answer {
      padding: 0 1.5rem 1.2rem;
      color: var(--text-secondary);
      display: none;
      border-left: 3px solid var(--primary);
      margin-left: 1rem;
      background: white;
    }
    .faq-item.active .faq-answer {
      display: block;
    }

    /* CTA 尾屏 */
    #cta {
      background-color: var(--bg-dark);
      text-align: center;
      color: white;
    }
    #cta h2 {
      color: white;
    }
    .cta-sub {
      color: rgba(255,255,255,0.7);
      margin: 1rem 0 2rem;
    }
    .btn-large {
      padding: 1rem 2.8rem;
      font-size: 1.2rem;
    }

    /* 页脚 */
    #footer {
      background: var(--bg-dark);
      color: rgba(255,255,255,0.55);
      padding: 2.5rem 0;
      font-size: 0.9rem;
    }
    .footer-content {
      display: flex;
      flex-direction: column;
      align-items: center;
      gap: 1.3rem;
    }
    .footer-links a {
      margin: 0 1rem;
      color: rgba(255,255,255,0.65);
    }
    .footer-links a:hover {
      color: var(--accent);
    }

    @media (max-width: 1024px) {
      .hero-grid { grid-template-columns: 1fr; }
      .hero-image { order: -1; }
      .features-grid { grid-template-columns: repeat(2,1fr); }
      .services-grid { grid-template-columns: repeat(2,1fr); }
      .cases-grid { grid-template-columns: repeat(2,1fr); }
    }
    @media (max-width: 768px) {
      .nav-links { display: none; }
      .hamburger { display: flex; }
      .mobile-menu {
        display: none;
        position: absolute;
        top: var(--nav-height);
        left: 0;
        width: 100%;
        background: white;
        flex-direction: column;
        padding: 1.5rem;
        box-shadow: 0 10px 20px rgba(0,0,0,0.05);
        gap: 1rem;
      }
      .mobile-menu.active { display: flex; }
      .services-grid, .cases-grid { grid-template-columns: 1fr; }
      .features-grid { grid-template-columns: 1fr; }
      .stats-grid { flex-direction: column; gap: 1.8rem; }
      .stat-divider { display: none; }
    }