/* roulang page: index */
:root {
      --primary: #1B5E20;
      --primary-dark: #144518;
      --primary-light: #E8F5E9;
      --accent: #FF6D00;
      --accent-hover: #E65100;
      --bg-page: #FAFAF5;
      --bg-card: #FFFFFF;
      --bg-dark: #0D3311;
      --bg-darker: #091A0B;
      --text-main: #1B1B1B;
      --text-body: #4A4A4A;
      --text-muted: #8A8A8A;
      --text-light: #B8C5B9;
      --border-color: #E8E5DF;
      --font-sans: -apple-system, "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", "Segoe UI", Roboto, sans-serif;
      --font-number: "Inter", "Segoe UI", "Helvetica Neue", sans-serif;
      --shadow-card: 0 8px 30px rgba(0,0,0,0.06);
      --shadow-card-hover: 0 18px 40px rgba(0,0,0,0.10);
      --shadow-nav: 0 2px 20px rgba(0,0,0,0.04);
      --radius-card: 20px;
      --radius-btn: 50px;
      --radius-img: 16px;
      --radius-tag: 8px;
      --transition: 0.25s ease;
    }
    * { box-sizing: border-box; margin: 0; padding: 0; }
    html { scroll-behavior: smooth; }
    body {
      font-family: var(--font-sans);
      background-color: var(--bg-page);
      color: var(--text-body);
      line-height: 1.7;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }
    img { display: block; max-width: 100%; height: auto; }
    a { text-decoration: none; color: inherit; }
    button, .btn { cursor: pointer; font-family: inherit; }

    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 24px;
    }

    /* 导航栏 */
    .nav {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      background: #FFFFFF;
      box-shadow: var(--shadow-nav);
      border-bottom: 1px solid var(--border-color);
      z-index: 1000;
      height: 72px;
      display: flex;
      align-items: center;
    }
    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 24px;
    }
    .logo {
      display: flex;
      align-items: center;
      gap: 8px;
      font-size: 24px;
      font-weight: 700;
      color: var(--primary);
      white-space: nowrap;
    }
    .logo-icon {
      width: 28px;
      height: 28px;
      background: var(--primary);
      mask: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" fill="none" stroke="white" stroke-width="2"><path d="M12 2L2 22h20L12 2z"/></svg>') center/contain no-repeat;
      -webkit-mask: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" fill="none" stroke="white" stroke-width="2"><path d="M12 2L2 22h20L12 2z"/></svg>') center/contain no-repeat;
      background: var(--primary);
      display: inline-block;
    }
    .nav-links {
      display: flex;
      align-items: center;
      gap: 32px;
      list-style: none;
    }
    .nav-links a {
      font-size: 15px;
      font-weight: 500;
      color: var(--text-body);
      padding: 8px 0;
      border-bottom: 2px solid transparent;
      transition: color var(--transition), border-color var(--transition);
    }
    .nav-links a:hover,
    .nav-links a.active {
      color: var(--primary);
      border-bottom-color: var(--primary);
    }
    .nav-cta {
      background: var(--primary);
      color: white;
      padding: 12px 28px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 15px;
      border: none;
      transition: background var(--transition), transform var(--transition), box-shadow var(--transition);
    }
    .nav-cta:hover {
      background: var(--primary-dark);
      transform: translateY(-2px);
      box-shadow: 0 10px 20px rgba(27,94,32,0.25);
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      background: none;
      border: none;
      cursor: pointer;
      padding: 4px;
    }
    .hamburger span {
      width: 26px;
      height: 2px;
      background: var(--primary);
      border-radius: 2px;
      transition: var(--transition);
    }
    .mobile-menu {
      display: none;
      position: fixed;
      top: 72px;
      left: 0;
      width: 100%;
      height: calc(100vh - 72px);
      background: rgba(13,51,17,0.97);
      flex-direction: column;
      align-items: center;
      justify-content: center;
      gap: 28px;
      z-index: 999;
    }
    .mobile-menu a {
      color: white;
      font-size: 20px;
      font-weight: 500;
    }
    .mobile-menu.active { display: flex; }

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

    .section-title {
      font-size: 36px;
      font-weight: 700;
      color: var(--text-main);
      line-height: 1.25;
      margin-bottom: 16px;
    }
    .section-sub {
      font-size: 16px;
      color: var(--text-muted);
      max-width: 680px;
      margin-bottom: 48px;
    }

    /* Hero */
    .hero {
      padding-top: 140px;
      padding-bottom: 80px;
      display: flex;
      align-items: center;
      gap: 60px;
    }
    .hero-left { flex: 1; }
    .hero-right { flex: 1.1; }
    .hero h1 {
      font-size: 48px;
      font-weight: 800;
      line-height: 1.15;
      color: var(--text-main);
      margin-bottom: 20px;
    }
    .hero-sub {
      font-size: 16px;
      color: #6B6B6B;
      margin-bottom: 32px;
      max-width: 480px;
    }
    .hero-buttons {
      display: flex;
      gap: 16px;
      margin-bottom: 32px;
      flex-wrap: wrap;
    }
    .btn-primary {
      background: var(--primary);
      color: white;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      border: none;
      transition: all var(--transition);
      display: inline-flex;
      align-items: center;
      gap: 8px;
    }
    .btn-primary:hover {
      background: var(--primary-dark);
      transform: translateY(-2px);
      box-shadow: 0 10px 20px rgba(27,94,32,0.3);
    }
    .btn-outline {
      background: transparent;
      color: var(--primary);
      border: 2px solid var(--primary);
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      transition: all var(--transition);
    }
    .btn-outline:hover {
      background: var(--primary);
      color: white;
      transform: translateY(-2px);
    }
    .hero-badges {
      display: flex;
      gap: 32px;
      align-items: center;
    }
    .badge-item {
      display: flex;
      flex-direction: column;
    }
    .badge-number {
      font-family: var(--font-number);
      font-size: 40px;
      font-weight: 800;
      color: var(--accent);
      line-height: 1.1;
    }
    .badge-label {
      font-size: 13px;
      color: var(--text-muted);
    }
    .hero-image {
      border-radius: 40px 12px 40px 12px;
      overflow: hidden;
      border: 4px solid var(--border-color);
      background: #ddd;
      aspect-ratio: 4/3;
    }
    .hero-image img {
      width: 100%;
      height: 100%;
      object-fit: cover;
    }

    /* 优势网格 */
    .advantages-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
      margin-top: 20px;
    }
    .adv-card {
      background: var(--bg-card);
      border-radius: var(--radius-card);
      padding: 32px;
      box-shadow: var(--shadow-card);
      transition: transform 0.3s ease, box-shadow 0.3s ease;
    }
    .adv-card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-card-hover);
    }
    .adv-icon {
      width: 64px;
      height: 64px;
      background: var(--primary-light);
      border-radius: 16px;
      display: flex;
      align-items: center;
      justify-content: center;
      margin-bottom: 20px;
      color: var(--primary);
    }
    .adv-card h3 {
      font-size: 22px;
      font-weight: 600;
      margin-bottom: 12px;
      color: var(--text-main);
    }
    .adv-card p {
      font-size: 15px;
      color: #6B6B6B;
    }

    /* 服务分栏 */
    .services-layout {
      display: flex;
      gap: 40px;
      align-items: flex-start;
    }
    .service-tabs {
      width: 200px;
      display: flex;
      flex-direction: column;
      gap: 8px;
    }
    .tab-btn {
      background: transparent;
      border: none;
      padding: 12px 20px;
      border-radius: 12px;
      font-size: 15px;
      font-weight: 500;
      text-align: left;
      color: var(--text-body);
      transition: 0.2s;
    }
    .tab-btn.active {
      background: var(--primary);
      color: white;
    }
    .tab-btn:hover:not(.active) {
      background: #F0F0EB;
    }
    .service-details {
      flex: 1;
      display: grid;
      grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
      gap: 24px;
    }
    .service-card {
      background: var(--bg-card);
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-card);
      transition: all 0.3s ease;
    }
    .service-card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-card-hover);
    }
    .service-img {
      height: 160px;
      background: #ccc;
    }
    .service-img img {
      width: 100%;
      height: 100%;
      object-fit: cover;
    }
    .service-info {
      padding: 20px;
    }
    .service-info h4 {
      font-size: 20px;
      font-weight: 600;
      margin-bottom: 8px;
    }
    .arrow-link {
      display: inline-flex;
      align-items: center;
      gap: 6px;
      color: var(--primary);
      font-weight: 600;
      font-size: 14px;
      margin-top: 12px;
      transition: gap 0.2s;
    }
    .arrow-link:hover { gap: 10px; }

    /* 案例瀑布 */
    .cases-masonry {
      columns: 3;
      column-gap: 24px;
    }
    .case-card {
      break-inside: avoid;
      background: var(--bg-card);
      border-radius: var(--radius-card);
      overflow: hidden;
      margin-bottom: 24px;
      box-shadow: var(--shadow-card);
      transition: 0.3s;
    }
    .case-card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-card-hover);
    }
    .case-img img {
      width: 100%;
      display: block;
    }
    .case-content {
      padding: 20px;
    }
    .case-tag {
      background: var(--accent);
      color: white;
      padding: 4px 12px;
      border-radius: 20px;
      font-size: 12px;
      font-weight: 600;
      display: inline-block;
      margin-bottom: 8px;
    }
    .case-number {
      font-family: var(--font-number);
      font-size: 24px;
      font-weight: 700;
      color: var(--accent);
    }

    /* 对比表 */
    .compare-row {
      display: flex;
      align-items: center;
      gap: 24px;
      justify-content: center;
      flex-wrap: wrap;
    }
    .compare-col {
      flex: 1;
      min-width: 280px;
      padding: 32px;
      border-radius: 16px;
    }
    .compare-left {
      background: #F5F5F0;
    }
    .compare-right {
      background: #E8F5E9;
      border: 2px solid var(--primary);
    }
    .vs-badge {
      width: 60px;
      height: 60px;
      background: var(--accent);
      color: white;
      font-weight: 800;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 20px;
    }

    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }
    .faq-item {
      background: white;
      border-radius: 12px;
      margin-bottom: 16px;
      overflow: hidden;
    }
    .faq-question {
      padding: 20px 24px;
      display: flex;
      align-items: center;
      gap: 16px;
      font-weight: 600;
      font-size: 17px;
      cursor: pointer;
    }
    .faq-num {
      width: 32px;
      height: 32px;
      background: var(--primary);
      color: white;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 14px;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s ease;
      background: #FAFAF5;
      padding: 0 24px;
    }
    .faq-item.open .faq-answer {
      max-height: 200px;
      padding: 20px 24px;
    }

    /* CTA */
    .cta-band {
      background: linear-gradient(135deg, #1B5E20 0%, #0D3311 100%);
      padding: 80px 0;
      text-align: center;
    }
    .cta-title {
      font-size: 40px;
      color: white;
      font-weight: 700;
    }
    .cta-sub {
      color: rgba(255,255,255,0.85);
      margin: 20px 0 32px;
    }
    .btn-white {
      background: white;
      color: var(--accent);
    }

    /* 页脚 */
    .footer {
      background: var(--bg-dark);
      color: var(--text-light);
      padding: 60px 0 20px;
      font-size: 15px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1.5fr;
      gap: 30px;
    }
    .copyright {
      background: var(--bg-darker);
      color: #6B7D6C;
      text-align: center;
      padding: 16px;
      margin-top: 40px;
    }

    @media (max-width: 1024px) {
      .hero { flex-direction: column; }
      .advantages-grid { grid-template-columns: repeat(2,1fr); }
      .cases-masonry { columns: 2; }
    }
    @media (max-width: 768px) {
      .nav-links, .nav-cta { display: none; }
      .hamburger { display: flex; }
      .hero h1 { font-size: 36px; }
      .advantages-grid { grid-template-columns: 1fr; }
      .services-layout { flex-direction: column; }
      .service-tabs { width: 100%; flex-direction: row; overflow-x: auto; }
      .cases-masonry { columns: 1; }
      .compare-row { flex-direction: column; }
      .footer-grid { grid-template-columns: 1fr 1fr; }
      .container { padding: 0 16px; }
      section { padding: 60px 0; }
    }