/* roulang page: index */
/* 设计变量与全局重置 */
    :root {
      --primary-green: #6BCB4A;
      --primary-green-dark: #5AB33E;
      --dark-stone: #2C3E30;
      --sun-yellow: #F5C542;
      --light-mint: #E8F5E1;
      --bg-gray-green: #F7F9F6;
      --white: #FFFFFF;
      --text-dark: #1F2329;
      --text-gray: #4A5568;
      --text-light: #86909C;
      --border-light: #E2E8F0;
      --shadow-sm: 0 2px 8px rgba(44,62,48,0.04);
      --shadow-md: 0 8px 24px rgba(44,62,48,0.08);
      --shadow-lg: 0 12px 32px rgba(44,62,48,0.12);
      --radius-card: 16px;
      --radius-btn: 30px;
      --radius-input: 12px;
      --transition: all 0.25s ease-out;
    }
    
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    
    body {
      font-family: 'Inter', 'PingFang SC', 'Microsoft YaHei', '苹方', '微软雅黑', system-ui, -apple-system, sans-serif;
      background-color: var(--bg-gray-green);
      color: var(--text-dark);
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
    }
    
    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
    }
    
    @media (min-width: 1024px) {
      .container {
        padding: 0 40px;
      }
    }
    
    /* 导航 */
    #header {
      position: sticky;
      top: 0;
      z-index: 50;
      transition: background 0.3s, box-shadow 0.3s;
      background: rgba(255,255,255,0.85);
      backdrop-filter: blur(12px);
      box-shadow: 0 1px 0 rgba(0,0,0,0.02);
    }
    #header.scrolled {
      background: rgba(255,255,255,0.96);
      box-shadow: 0 4px 20px rgba(0,0,0,0.04);
    }
    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 64px;
    }
    .logo {
      display: flex;
      align-items: center;
      gap: 0.5rem;
      font-weight: 700;
      font-size: 1.5rem;
      color: var(--dark-stone);
      text-decoration: none;
    }
    .logo i {
      color: var(--primary-green);
      font-size: 2rem;
    }
    .nav-links {
      display: flex;
      gap: 2rem;
      align-items: center;
    }
    .nav-links a {
      text-decoration: none;
      color: var(--text-gray);
      font-weight: 500;
      font-size: 0.95rem;
      transition: color 0.2s;
      position: relative;
    }
    .nav-links a:hover,
    .nav-links a.active {
      color: var(--primary-green);
    }
    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: -6px;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--primary-green);
      transition: width 0.25s ease;
    }
    .nav-links a:hover::after,
    .nav-links a.active::after {
      width: 100%;
    }
    .mobile-menu-btn {
      display: none;
      background: none;
      border: none;
      font-size: 1.8rem;
      color: var(--dark-stone);
      cursor: pointer;
    }
    @media (max-width: 768px) {
      .nav-links {
        display: none;
        position: fixed;
        top: 64px;
        left: 0;
        width: 100%;
        background: white;
        flex-direction: column;
        padding: 2rem;
        box-shadow: var(--shadow-md);
        gap: 1.5rem;
      }
      .nav-links.active {
        display: flex;
      }
      .nav-links a {
        font-size: 1.1rem;
        border-left: 3px solid transparent;
        padding-left: 12px;
      }
      .nav-links a.active {
        border-left-color: var(--primary-green);
      }
      .mobile-menu-btn {
        display: block;
      }
    }
    
    /* 按钮系统 */
    .btn-primary {
      background: var(--primary-green);
      color: white;
      border: none;
      padding: 0.9rem 2.2rem;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 1rem;
      cursor: pointer;
      transition: var(--transition);
      box-shadow: 0 4px 10px rgba(107,203,74,0.25);
      display: inline-block;
      text-decoration: none;
    }
    .btn-primary:hover {
      background: var(--primary-green-dark);
      box-shadow: 0 8px 18px rgba(90,179,62,0.3);
      transform: translateY(-1px);
    }
    .btn-outline {
      background: transparent;
      color: var(--primary-green);
      border: 1.5px solid var(--primary-green);
      padding: 0.85rem 2rem;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 1rem;
      cursor: pointer;
      transition: var(--transition);
      text-decoration: none;
      display: inline-block;
    }
    .btn-outline:hover {
      background: var(--light-mint);
      transform: translateY(-1px);
    }
    .btn-link {
      color: var(--primary-green);
      font-weight: 600;
      text-decoration: none;
      border-bottom: 1px solid transparent;
      transition: 0.2s;
    }
    .btn-link:hover {
      border-bottom-color: var(--primary-green);
      color: var(--primary-green-dark);
    }
    
    /* 板块标题 */
    .section-title {
      font-size: 2rem;
      font-weight: 700;
      color: var(--dark-stone);
      margin-bottom: 0.5rem;
      line-height: 1.3;
    }
    .section-subtitle {
      color: var(--text-gray);
      font-size: 1.1rem;
      margin-bottom: 2.5rem;
    }
    
    /* 卡片通用 */
    .card {
      background: white;
      border-radius: var(--radius-card);
      padding: 24px;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
    }
    .card:hover {
      box-shadow: var(--shadow-md);
      transform: translateY(-4px);
    }
    
    /* Hero */
    #hero {
      background: linear-gradient(135deg, #F7F9F6 0%, #ffffff 100%);
      padding: 3rem 0 5rem;
      position: relative;
    }
    .hero-grid {
      display: flex;
      align-items: center;
      gap: 3rem;
    }
    .hero-left {
      flex: 1;
    }
    .hero-right {
      flex: 1;
      position: relative;
    }
    .hero-right img {
      width: 100%;
      border-radius: 24px;
      box-shadow: 0 20px 35px rgba(44,62,48,0.15);
    }
    @media (max-width: 768px) {
      .hero-grid {
        flex-direction: column;
      }
    }
    
    /* 亮点网格 */
    .highlights-grid {
      display: grid;
      grid-template-columns: repeat(3,1fr);
      gap: 24px;
    }
    @media (max-width: 768px) {
      .highlights-grid {
        grid-template-columns: 1fr;
      }
    }
    
    /* 案例瀑布 */
    .showcase-grid {
      display: grid;
      grid-template-columns: repeat(3,1fr);
      gap: 24px;
    }
    @media (max-width: 1024px) {
      .showcase-grid { grid-template-columns: repeat(2,1fr); }
    }
    @media (max-width: 640px) {
      .showcase-grid { grid-template-columns: 1fr; }
    }
    
    /* 方案对比 */
    .compare-grid {
      display: grid;
      grid-template-columns: repeat(3,1fr);
      gap: 24px;
    }
    @media (max-width: 768px) {
      .compare-grid {
        grid-template-columns: 1fr;
        overflow-x: auto;
        display: flex;
        scroll-snap-type: x mandatory;
      }
      .compare-grid > * {
        min-width: 280px;
        scroll-snap-align: start;
      }
    }
    
    /* FAQ 手风琴 */
    .faq-item {
      background: rgba(255,255,255,0.1);
      backdrop-filter: blur(4px);
      border-radius: 12px;
      margin-bottom: 12px;
      overflow: hidden;
    }
    .faq-question {
      padding: 1.2rem;
      font-weight: 600;
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
      background: rgba(255,255,255,0.15);
    }
    .faq-answer {
      padding: 0 1.2rem 1.2rem;
      display: none;
      color: rgba(255,255,255,0.85);
    }
    .faq-item.active .faq-answer {
      display: block;
    }
    
    /* 联系表单 */
    .contact-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 40px;
    }
    @media (max-width: 768px) {
      .contact-grid { grid-template-columns: 1fr; }
    }
    
    input, textarea {
      width: 100%;
      padding: 0.9rem 1.2rem;
      border: 1px solid var(--border-light);
      border-radius: var(--radius-input);
      font-size: 1rem;
      transition: 0.2s;
      background: white;
    }
    input:focus, textarea:focus {
      outline: none;
      border-color: var(--primary-green);
      box-shadow: 0 0 0 3px rgba(107,203,74,0.2);
    }
    
    footer {
      background: var(--dark-stone);
      color: white;
      padding: 3rem 0 1.5rem;
    }