/* roulang page: index */
:root {
      --primary-deep-green: #1A3C2A;
      --secondary-bright-orange: #E85D04;
      --warm-cream: #F4F1E1;
      --gold-medal: #C7A951;
      --text-dark: #1E1E1E;
      --text-gray: #4A4A4A;
      --text-light: #FFFFFF;
      --card-bg: #FFFFFF;
      --border-light: #E0DCD0;
      --shadow-sm: 0 4px 12px rgba(0,0,0,0.06);
      --shadow-md: 0 8px 24px rgba(0,0,0,0.12);
      --radius-card: 12px;
      --radius-btn: 8px;
      --font-title: 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', system-ui, -apple-system, sans-serif;
      --font-body: 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', system-ui, -apple-system, sans-serif;
      --transition-smooth: 0.25s ease;
    }

    * {
      box-sizing: border-box;
    }

    body {
      font-family: var(--font-body);
      background-color: var(--warm-cream);
      color: var(--text-dark);
      line-height: 1.6;
      font-size: 16px;
      margin: 0;
      padding: 0;
      -webkit-font-smoothing: antialiased;
    }

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

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

    button, input, textarea {
      font-family: inherit;
    }

    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding-left: 20px;
      padding-right: 20px;
    }

    /* 导航 */
    #main-nav {
      background-color: var(--primary-deep-green);
      padding: 0;
      position: sticky;
      top: 0;
      z-index: 100;
      width: 100%;
      height: 64px;
      display: flex;
      align-items: center;
      box-shadow: 0 2px 0 var(--secondary-bright-orange);
    }

    .nav-container {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 20px;
    }

    .brand-logo {
      font-family: var(--font-title);
      font-weight: 800;
      font-size: 22px;
      color: var(--text-light);
      letter-spacing: 1px;
    }

    .nav-links {
      display: flex;
      gap: 28px;
      align-items: center;
      list-style: none;
      margin: 0;
    }

    .nav-links a {
      color: rgba(255,255,255,0.9);
      font-weight: 600;
      font-size: 16px;
      padding: 8px 0;
      border-bottom: 2px solid transparent;
      transition: border-color var(--transition-smooth), color var(--transition-smooth);
    }

    .nav-links a:hover,
    .nav-links a.active {
      color: #fff;
      border-bottom-color: var(--secondary-bright-orange);
    }

    .hamburger {
      display: none;
      background: none;
      border: none;
      color: white;
      font-size: 28px;
      cursor: pointer;
    }

    .mobile-menu {
      display: none;
      position: fixed;
      top: 64px;
      left: 0;
      width: 100%;
      height: calc(100vh - 64px);
      background: var(--primary-deep-green);
      flex-direction: column;
      align-items: center;
      justify-content: center;
      gap: 32px;
      z-index: 99;
      opacity: 0;
      transform: translateY(-20px);
      transition: opacity 0.3s ease, transform 0.3s ease;
      pointer-events: none;
    }

    .mobile-menu.open {
      display: flex;
      opacity: 1;
      transform: translateY(0);
      pointer-events: auto;
    }

    .mobile-menu a {
      color: white;
      font-size: 22px;
      font-weight: 700;
      border-bottom: 2px solid transparent;
      padding: 8px 16px;
    }

    .mobile-menu a:hover {
      border-bottom-color: var(--secondary-bright-orange);
    }

    /* Hero */
    #hero {
      min-height: 100vh;
      display: flex;
      align-items: center;
      background: linear-gradient(135deg, rgba(26,60,42,0.8) 0%, rgba(15,40,24,0.9) 100%), url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      color: white;
      position: relative;
    }

    .hero-content {
      max-width: 700px;
    }

    .hero-content h1 {
      font-family: var(--font-title);
      font-size: 52px;
      font-weight: 800;
      line-height: 1.2;
      margin-bottom: 24px;
      color: white;
    }

    .hero-sub {
      font-size: 18px;
      opacity: 0.9;
      margin-bottom: 40px;
      font-weight: 400;
    }

    .hero-buttons {
      display: flex;
      gap: 20px;
      flex-wrap: wrap;
    }

    .btn-primary {
      background: var(--secondary-bright-orange);
      color: white;
      padding: 14px 36px;
      border-radius: var(--radius-btn);
      font-weight: 700;
      font-size: 18px;
      border: none;
      transition: background var(--transition-smooth), transform var(--transition-smooth);
      display: inline-block;
      text-align: center;
    }

    .btn-primary:hover {
      background: #C94A00;
      transform: scale(1.03);
      color: white;
    }

    .btn-secondary {
      background: transparent;
      border: 2px solid var(--primary-deep-green);
      color: var(--primary-deep-green);
      padding: 14px 36px;
      border-radius: var(--radius-btn);
      font-weight: 700;
      font-size: 18px;
      transition: all var(--transition-smooth);
      display: inline-block;
      text-align: center;
    }

    .btn-secondary:hover {
      background: var(--primary-deep-green);
      color: white;
    }

    .hero .btn-secondary {
      border-color: white;
      color: white;
    }

    .hero .btn-secondary:hover {
      background: white;
      color: var(--primary-deep-green);
    }

    /* 通用板块 */
    section {
      padding: 80px 0;
    }

    .section-title {
      font-family: var(--font-title);
      font-size: 36px;
      font-weight: 800;
      color: var(--primary-deep-green);
      margin-bottom: 16px;
      text-align: center;
    }

    .section-desc {
      color: var(--text-gray);
      text-align: center;
      max-width: 700px;
      margin: 0 auto 48px;
      font-size: 17px;
    }

    /* 指标看板 */
    .metrics-wrapper {
      background: var(--card-bg);
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-sm);
      padding: 40px;
    }

    .metrics-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
      text-align: center;
    }

    .metric-item .metric-number {
      font-size: 48px;
      font-weight: 800;
      color: var(--primary-deep-green);
      line-height: 1.1;
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 6px;
    }

    .metric-prefix {
      color: var(--gold-medal);
      font-size: 36px;
    }

    .metric-label {
      font-size: 15px;
      color: var(--text-gray);
      margin-top: 8px;
      font-weight: 500;
    }

    /* 服务卡片 */
    .services-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 28px;
    }

    .service-card {
      background: var(--card-bg);
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-sm);
      padding: 28px 24px;
      transition: all var(--transition-smooth);
      display: flex;
      flex-direction: column;
    }

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

    .card-icon {
      width: 80px;
      height: 80px;
      background: var(--warm-cream);
      border-radius: 20px;
      display: flex;
      align-items: center;
      justify-content: center;
      margin-bottom: 20px;
    }

    .card-icon img {
      width: 48px;
      height: 48px;
      object-fit: contain;
    }

    .service-card h3 {
      font-family: var(--font-title);
      font-size: 22px;
      font-weight: 700;
      color: var(--primary-deep-green);
      margin-bottom: 12px;
    }

    .service-card p {
      color: var(--text-gray);
      font-size: 15px;
      margin-bottom: 24px;
      flex: 1;
    }

    .card-link {
      color: var(--secondary-bright-orange);
      font-weight: 700;
      font-size: 16px;
      display: inline-flex;
      align-items: center;
      gap: 6px;
      transition: gap var(--transition-smooth);
    }

    .card-link:hover {
      gap: 10px;
      color: #C94A00;
    }

    /* 对比 */
    .compare-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 32px;
    }

    .compare-card {
      background: var(--card-bg);
      border-radius: var(--radius-card);
      padding: 32px;
      box-shadow: var(--shadow-sm);
    }

    .compare-card.traditional {
      border: 1px solid #D0D0D0;
      background: #f9f9f9;
    }

    .compare-card.niuba {
      border: 2px solid var(--primary-deep-green);
      background: #F4F9F5;
    }

    .compare-card h3 {
      font-size: 24px;
      font-weight: 800;
      margin-bottom: 24px;
    }

    .compare-list {
      list-style: none;
      padding: 0;
      margin: 0;
    }

    .compare-list li {
      display: flex;
      align-items: center;
      gap: 12px;
      margin-bottom: 18px;
      font-size: 16px;
    }

    .icon-check {
      color: var(--gold-medal);
      font-weight: bold;
    }

    .icon-cross {
      color: #999;
      text-decoration: line-through;
    }

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

    .faq-item {
      border-bottom: 1px solid var(--border-light);
      padding: 4px 0;
    }

    .faq-question {
      background: none;
      border: none;
      width: 100%;
      text-align: left;
      font-weight: 700;
      font-size: 18px;
      padding: 20px 16px;
      display: flex;
      justify-content: space-between;
      align-items: center;
      color: var(--text-dark);
      cursor: pointer;
      transition: background var(--transition-smooth);
      border-radius: 8px;
    }

    .faq-question:hover {
      background: #F9F7F0;
    }

    .faq-icon {
      color: var(--secondary-bright-orange);
      font-size: 20px;
      transition: transform 0.2s;
    }

    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease, padding 0.3s ease;
      padding: 0 16px;
      color: var(--text-gray);
      font-size: 16px;
      background: #FCFAF5;
      border-radius: 0 0 8px 8px;
    }

    .faq-item.active .faq-answer {
      max-height: 200px;
      padding: 16px;
    }

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

    /* CTA */
    #cta {
      background: linear-gradient(135deg, #1A3C2A 0%, #0F2818 100%);
      color: white;
      text-align: center;
      padding: 80px 0;
    }

    .cta-form {
      max-width: 500px;
      margin: 32px auto 0;
      display: flex;
      flex-direction: column;
      gap: 20px;
    }

    .cta-form input,
    .cta-form textarea {
      background: rgba(255,255,255,0.15);
      border: 1px solid rgba(255,255,255,0.4);
      border-radius: var(--radius-btn);
      padding: 14px 18px;
      color: white;
      font-size: 16px;
      outline: none;
      transition: border var(--transition-smooth), box-shadow var(--transition-smooth);
    }

    .cta-form input::placeholder,
    .cta-form textarea::placeholder {
      color: rgba(255,255,255,0.7);
    }

    .cta-form input:focus,
    .cta-form textarea:focus {
      border-color: var(--secondary-bright-orange);
      box-shadow: 0 0 0 3px rgba(232,93,4,0.3);
    }

    .btn-submit {
      background: var(--secondary-bright-orange);
      color: white;
      border: none;
      padding: 16px;
      font-weight: 700;
      font-size: 18px;
      border-radius: var(--radius-btn);
      cursor: pointer;
      transition: background var(--transition-smooth);
    }

    .btn-submit:hover {
      background: #C94A00;
    }

    /* Footer */
    #footer {
      background: #0F2818;
      color: #CCCCCC;
      padding: 48px 0 24px;
    }

    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr;
      gap: 40px;
    }

    .footer-brand h4 {
      color: white;
      font-weight: 800;
      font-size: 22px;
      margin-bottom: 12px;
    }

    .footer-contact p {
      margin: 6px 0;
      font-size: 15px;
    }

    .copyright {
      margin-top: 32px;
      font-size: 14px;
      color: #aaa;
      border-top: 1px solid #2e4a35;
      padding-top: 20px;
      text-align: center;
    }

    @media (max-width: 1024px) {
      .services-grid {
        grid-template-columns: repeat(2, 1fr);
      }
    }

    @media (max-width: 768px) {
      .nav-links {
        display: none;
      }
      .hamburger {
        display: block;
      }
      #main-nav {
        height: 56px;
      }
      .hero-content h1 {
        font-size: 34px;
      }
      .hero-buttons {
        flex-direction: column;
        align-items: flex-start;
      }
      .metrics-grid {
        grid-template-columns: 1fr 1fr;
      }
      .services-grid {
        grid-template-columns: 1fr;
      }
      .compare-grid {
        grid-template-columns: 1fr;
      }
      section {
        padding: 48px 0;
      }
      .section-title {
        font-size: 28px;
      }
      .footer-grid {
        grid-template-columns: 1fr;
        text-align: center;
      }
      .metric-number {
        font-size: 38px;
      }
    }

    @media (max-width: 520px) {
      .hero-content h1 {
        font-size: 28px;
      }
      .metrics-grid {
        gap: 16px;
      }
    }