/* roulang page: index */
/* 设计变量 */
    :root {
      --primary: #1B8E3F;
      --primary-dark: #0D5C2B;
      --accent: #F28C28;
      --accent-dark: #E07B1F;
      --bg: #FAFAF8;
      --white: #FFFFFF;
      --text: #2D2D2D;
      --text-light: #6B6B6B;
      --border: #E8E8E4;
      --shadow-sm: 0 4px 16px rgba(0,0,0,0.04), 0 1px 4px rgba(0,0,0,0.02);
      --shadow-hover: 0 8px 24px rgba(0,0,0,0.08), 0 2px 8px rgba(0,0,0,0.04);
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-input: 6px;
      --font-sans: 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', sans-serif;
    }
    
    /* Reset & Base */
    *, *::before, *::after {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }
    
    html {
      scroll-behavior: smooth;
      scroll-padding-top: 80px;
    }
    
    body {
      font-family: var(--font-sans);
      font-size: 16px;
      font-weight: 400;
      line-height: 1.6;
      color: var(--text);
      background-color: var(--bg);
      -webkit-font-smoothing: antialiased;
      -moz-osx-font-smoothing: grayscale;
    }
    
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    
    a {
      text-decoration: none;
      color: inherit;
    }
    
    button, input, textarea {
      font-family: inherit;
    }
    
    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
    }
    
    /* 导航 */
    #nav {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 64px;
      background: var(--white);
      box-shadow: 0 1px 0 rgba(0,0,0,0.04);
      z-index: 1000;
      display: flex;
      align-items: center;
      transition: box-shadow 0.2s;
    }
    
    #nav.scrolled {
      box-shadow: 0 2px 8px rgba(0,0,0,0.08);
    }
    
    .nav-container {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
    }
    
    .logo {
      display: flex;
      align-items: center;
      gap: 8px;
      font-weight: 700;
      font-size: 24px;
      color: var(--primary-dark);
      letter-spacing: 0.5px;
    }
    
    .logo i {
      font-size: 28px;
      color: var(--accent);
    }
    
    .nav-links {
      display: flex;
      align-items: center;
      gap: 32px;
      list-style: none;
    }
    
    .nav-links a {
      font-size: 15px;
      font-weight: 500;
      color: var(--text);
      padding: 8px 0;
      position: relative;
      transition: color 0.2s;
    }
    
    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--primary);
      transition: width 0.2s;
    }
    
    .nav-links a:hover,
    .nav-links a.active {
      color: var(--primary);
    }
    
    .nav-links a.active::after {
      width: 100%;
    }
    
    .btn-nav {
      background: var(--primary);
      color: white !important;
      padding: 10px 22px !important;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 14px;
      transition: background 0.2s, transform 0.1s;
    }
    
    .btn-nav:hover {
      background: var(--primary-dark);
    }
    
    .menu-toggle {
      display: none;
      background: none;
      border: none;
      font-size: 24px;
      color: var(--text);
      cursor: pointer;
    }
    
    /* Hero */
    #hero {
      padding: 140px 0 100px;
      background: var(--bg);
      position: relative;
      overflow: hidden;
    }
    
    #hero::before {
      content: '';
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background-image: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100" fill="none"><path d="M0 25 L50 0 L100 25 L100 75 L50 100 L0 75 Z" stroke="%231B8E3F" stroke-width="0.5" opacity="0.05"/></svg>');
      background-size: 60px 60px;
      pointer-events: none;
    }
    
    .hero-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 60px;
      align-items: center;
      position: relative;
      z-index: 2;
    }
    
    .hero-text h1 {
      font-size: 44px;
      font-weight: 700;
      line-height: 1.2;
      color: var(--primary-dark);
      margin-bottom: 20px;
    }
    
    .hero-text .subtitle {
      font-size: 18px;
      color: var(--text-light);
      margin-bottom: 36px;
      line-height: 1.5;
    }
    
    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    
    .btn {
      display: inline-block;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 16px;
      text-align: center;
      cursor: pointer;
      transition: all 0.2s ease;
      border: none;
    }
    
    .btn-primary {
      background: var(--primary);
      color: white;
      box-shadow: 0 2px 8px rgba(27,142,63,0.2);
    }
    
    .btn-primary:hover {
      background: var(--primary-dark);
      transform: translateY(-2px);
      box-shadow: 0 6px 16px rgba(13,92,43,0.25);
    }
    
    .btn-secondary {
      background: transparent;
      color: var(--primary);
      border: 2px solid var(--primary);
    }
    
    .btn-secondary:hover {
      background: rgba(27,142,63,0.1);
      border-color: var(--primary-dark);
      transform: translateY(-2px);
    }
    
    .hero-image {
      background: linear-gradient(135deg, rgba(27,142,63,0.08) 0%, rgba(242,140,40,0.05) 100%);
      border-radius: 24px;
      overflow: hidden;
      display: flex;
      align-items: center;
      justify-content: center;
      min-height: 360px;
    }
    
    .hero-image img {
      width: 100%;
      height: 100%;
      object-fit: cover;
      border-radius: 24px;
    }
    
    /* 通用板块标题 */
    .section-title {
      text-align: center;
      margin-bottom: 56px;
    }
    
    .section-title h2 {
      font-size: 32px;
      font-weight: 600;
      color: var(--primary-dark);
      margin-bottom: 12px;
    }
    
    .section-title p {
      color: var(--text-light);
      font-size: 16px;
    }
    
    section {
      padding: 90px 0;
    }
    
    /* 服务卡片 */
    .service-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    
    .service-card {
      background: var(--white);
      border-radius: var(--radius-card);
      padding: 32px 24px;
      text-align: center;
      box-shadow: var(--shadow-sm);
      transition: all 0.25s ease;
    }
    
    .service-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
    }
    
    .service-icon {
      font-size: 40px;
      color: var(--primary);
      margin-bottom: 20px;
    }
    
    .service-card h3 {
      font-size: 20px;
      font-weight: 500;
      margin-bottom: 12px;
    }
    
    .service-card p {
      color: var(--text-light);
      font-size: 16px;
    }
    
    /* 优势数据 */
    .advantage-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
      text-align: center;
    }
    
    .stat-item {
      background: var(--white);
      padding: 28px 16px;
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-sm);
    }
    
    .stat-number {
      font-size: 48px;
      font-weight: 700;
      color: var(--accent);
      line-height: 1.1;
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 4px;
    }
    
    .stat-number i {
      font-size: 24px;
      color: var(--primary);
    }
    
    .stat-label {
      color: var(--text-light);
      margin-top: 8px;
    }
    
    /* 案例卡片 */
    .case-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    
    .case-card {
      background: var(--white);
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
      transition: all 0.25s;
    }
    
    .case-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
    }
    
    .case-img {
      aspect-ratio: 16 / 9;
      background: #f0f0ed;
      overflow: hidden;
    }
    
    .case-img img {
      width: 100%;
      height: 100%;
      object-fit: cover;
      transition: transform 0.3s;
    }
    
    .case-card:hover .case-img img {
      transform: scale(1.03);
    }
    
    .case-content {
      padding: 20px;
    }
    
    .case-tag {
      display: inline-block;
      background: rgba(27,142,63,0.1);
      color: var(--primary-dark);
      font-size: 13px;
      padding: 4px 12px;
      border-radius: 20px;
      margin-bottom: 12px;
    }
    
    .case-content h3 {
      font-size: 20px;
      font-weight: 500;
      margin-bottom: 8px;
    }
    
    .case-content p {
      color: var(--text-light);
      font-size: 15px;
    }
    
    /* 解决方案 左右交替 */
    .solution-block {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 60px;
      align-items: center;
      margin-bottom: 80px;
    }
    
    .solution-block:last-child {
      margin-bottom: 0;
    }
    
    .solution-img {
      background: #eef2ed;
      border-radius: 20px;
      overflow: hidden;
    }
    
    .solution-img img {
      width: 100%;
      height: auto;
    }
    
    .solution-text h3 {
      font-size: 28px;
      font-weight: 600;
      color: var(--primary-dark);
      margin-bottom: 16px;
    }
    
    .solution-text p {
      color: var(--text-light);
      margin-bottom: 12px;
    }
    
    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }
    
    .faq-item {
      background: var(--white);
      border-radius: var(--radius-card);
      margin-bottom: 16px;
      box-shadow: var(--shadow-sm);
      overflow: hidden;
    }
    
    .faq-question {
      width: 100%;
      background: none;
      border: none;
      padding: 20px 24px;
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-size: 18px;
      font-weight: 500;
      cursor: pointer;
      color: var(--text);
      text-align: left;
    }
    
    .faq-question i {
      color: var(--accent);
      margin-right: 12px;
      font-size: 18px;
    }
    
    .faq-toggle {
      font-size: 20px;
      color: var(--text-light);
      transition: transform 0.2s;
    }
    
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease, padding 0.3s;
      background: #F5F5F2;
      padding: 0 24px;
    }
    
    .faq-item.active .faq-answer {
      max-height: 200px;
      padding: 16px 24px;
    }
    
    .faq-item.active .faq-toggle {
      transform: rotate(45deg);
    }
    
    /* 联系 */
    .contact-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 48px;
      background: var(--white);
      border-radius: 24px;
      padding: 48px;
      box-shadow: var(--shadow-sm);
    }
    
    .contact-form input,
    .contact-form textarea {
      width: 100%;
      padding: 14px 16px;
      border: 1px solid var(--border);
      border-radius: var(--radius-input);
      margin-bottom: 16px;
      font-size: 16px;
      transition: border 0.2s;
      background: #FAFAFA;
    }
    
    .contact-form input:focus,
    .contact-form textarea:focus {
      outline: none;
      border-color: var(--primary);
      background: white;
    }
    
    .btn-submit {
      background: var(--accent);
      color: white;
      padding: 14px 32px;
      border: none;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 16px;
      cursor: pointer;
      transition: background 0.2s;
      width: 100%;
    }
    
    .btn-submit:hover {
      background: var(--accent-dark);
    }
    
    .contact-info {
      display: flex;
      flex-direction: column;
      justify-content: center;
      gap: 24px;
      color: var(--text-light);
    }
    
    .contact-info i {
      color: var(--primary);
      margin-right: 8px;
    }
    
    /* 页脚 */
    #footer {
      background: var(--primary-dark);
      color: #D0D0D0;
      padding: 60px 0 30px;
    }
    
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr;
      gap: 40px;
      margin-bottom: 40px;
    }
    
    .footer-logo {
      font-size: 24px;
      font-weight: 700;
      color: white;
    }
    
    .footer-desc {
      margin-top: 12px;
      font-size: 15px;
    }
    
    .footer-links a {
      display: block;
      margin-bottom: 10px;
      color: #D0D0D0;
      transition: color 0.2s;
    }
    
    .footer-links a:hover {
      color: var(--accent);
    }
    
    .social-icons {
      display: flex;
      gap: 16px;
      font-size: 22px;
    }
    
    .social-icons a {
      color: #D0D0D0;
      transition: color 0.2s;
    }
    
    .social-icons a:hover {
      color: var(--accent);
    }
    
    .copyright {
      border-top: 1px solid rgba(255,255,255,0.1);
      padding-top: 24px;
      text-align: center;
      font-size: 14px;
    }
    
    /* 响应式 */
    @media (max-width: 1024px) {
      .hero-grid, .solution-block, .contact-grid {
        gap: 32px;
      }
    }
    
    @media (max-width: 768px) {
      .nav-links {
        display: none;
        position: absolute;
        top: 64px;
        left: 0;
        width: 100%;
        background: var(--bg);
        flex-direction: column;
        padding: 24px;
        box-shadow: 0 8px 16px rgba(0,0,0,0.05);
      }
      .nav-links.active {
        display: flex;
      }
      .menu-toggle {
        display: block;
      }
      .hero-grid {
        grid-template-columns: 1fr;
      }
      .hero-image {
        order: -1;
      }
      .service-grid, .case-grid {
        grid-template-columns: 1fr 1fr;
      }
      .advantage-grid {
        grid-template-columns: 1fr 1fr;
      }
      .solution-block {
        grid-template-columns: 1fr;
      }
      .contact-grid {
        grid-template-columns: 1fr;
      }
      .footer-grid {
        grid-template-columns: 1fr;
      }
      h1 {
        font-size: 36px;
      }
    }
    
    @media (max-width: 480px) {
      .service-grid, .case-grid, .advantage-grid {
        grid-template-columns: 1fr;
      }
      .hero-buttons .btn {
        width: 100%;
      }
      section {
        padding: 60px 0;
      }
    }