/* roulang page: index */
/* ----- 设计变量与基础重置 ----- */
    :root {
      --terracotta: #C67B5C;
      --terracotta-deep: #B15A3A;
      --marble-white: #F9F6F0;
      --kelly-green: #4A7C59;
      --kelly-deep: #3A6247;
      --charcoal: #2C2C2C;
      --gray-text: #4A4A4A;
      --gray-light: #6E6E6E;
      --border-light: #E5E0D8;
      --white-soft: #FFFFFF;
      --shadow-card: 0 4px 20px rgba(0,0,0,0.04);
      --shadow-hover: 0 12px 32px rgba(0,0,0,0.08);
      --radius-sm: 8px;
      --radius-md: 16px;
      --radius-pill: 24px;
      --font-serif: 'Playfair Display', 'Noto Serif SC', 'Times New Roman', serif;
      --font-sans: 'Inter', 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', sans-serif;
      --spacing-section: 100px;
      --container-max: 1200px;
    }
    
    * {
      box-sizing: border-box;
    }
    
    body {
      font-family: var(--font-sans);
      background-color: var(--marble-white);
      color: var(--charcoal);
      line-height: 1.8;
      margin: 0;
      -webkit-font-smoothing: antialiased;
      -moz-osx-font-smoothing: grayscale;
    }
    
    h1, h2, h3, .serif-title {
      font-family: var(--font-serif);
      font-weight: 600;
      letter-spacing: -0.01em;
      line-height: 1.3;
    }
    
    a {
      color: var(--terracotta);
      transition: color 0.2s ease, opacity 0.2s;
    }
    a:hover {
      color: var(--terracotta-deep);
      text-decoration: none;
    }
    
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    
    .container-custom {
      max-width: var(--container-max);
      margin: 0 auto;
      padding: 0 24px;
    }
    
    /* 按钮系统 */
    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 12px 32px;
      border-radius: var(--radius-pill);
      font-weight: 500;
      letter-spacing: 0.3px;
      transition: all 0.25s ease;
      border: 1px solid transparent;
      cursor: pointer;
      font-size: 1rem;
      text-decoration: none;
      background: transparent;
    }
    .btn-outline {
      border: 1px solid var(--terracotta);
      color: var(--terracotta);
      background: transparent;
    }
    .btn-outline:hover {
      background: rgba(198,123,92,0.05);
      color: var(--terracotta-deep);
      border-color: var(--terracotta-deep);
    }
    .btn-primary {
      background: var(--kelly-green);
      color: white;
      border: 1px solid var(--kelly-green);
      box-shadow: 0 2px 8px rgba(74,124,89,0.15);
    }
    .btn-primary:hover {
      background: var(--kelly-deep);
      border-color: var(--kelly-deep);
      color: white;
      transform: translateY(-1px);
      box-shadow: 0 8px 18px rgba(74,124,89,0.25);
    }
    .btn-large {
      padding: 14px 40px;
      font-size: 1.1rem;
    }
    
    /* ----- 导航：白底内容平台风格 ----- */
    .site-header {
      background: var(--marble-white);
      border-bottom: 1px solid var(--border-light);
      position: sticky;
      top: 0;
      z-index: 50;
      backdrop-filter: blur(4px);
      background: rgba(249,246,240,0.92);
    }
    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      padding: 0 24px;
      height: 72px;
      max-width: var(--container-max);
      margin: 0 auto;
    }
    .logo-area {
      display: flex;
      align-items: center;
      gap: 12px;
      text-decoration: none;
      color: var(--terracotta);
    }
    .logo-icon {
      font-size: 28px;
      color: var(--terracotta);
    }
    .logo-text {
      font-family: var(--font-serif);
      font-weight: 700;
      font-size: 1.8rem;
      letter-spacing: 0.5px;
      color: var(--terracotta);
    }
    .nav-links {
      display: flex;
      gap: 32px;
      list-style: none;
      margin: 0;
      align-items: center;
    }
    .nav-links a {
      color: var(--charcoal);
      font-weight: 500;
      font-size: 0.95rem;
      padding: 8px 0;
      border-bottom: 2px solid transparent;
      transition: 0.2s;
      text-decoration: none;
    }
    .nav-links a:hover {
      color: var(--terracotta);
      border-bottom-color: var(--terracotta);
    }
    .nav-right {
      display: flex;
      align-items: center;
      gap: 16px;
    }
    .search-box {
      position: relative;
      display: flex;
      align-items: center;
    }
    .search-box input {
      border: 1px solid var(--terracotta);
      border-radius: 20px;
      padding: 8px 16px 8px 36px;
      font-size: 0.9rem;
      background: white;
      width: 160px;
      transition: all 0.2s;
      outline: none;
    }
    .search-box input:focus {
      border-color: var(--terracotta-deep);
      width: 200px;
    }
    .search-icon {
      position: absolute;
      left: 14px;
      color: var(--terracotta);
      font-size: 0.9rem;
    }
    
    /* 汉堡菜单 (移动端) */
    .menu-toggle {
      display: none;
      background: none;
      border: none;
      font-size: 1.8rem;
      color: var(--charcoal);
    }
    
    /* ----- 板块通用 ----- */
    section {
      padding: var(--spacing-section) 0;
    }
    .section-title {
      font-size: 2.5rem;
      margin-bottom: 16px;
      color: var(--charcoal);
    }
    .section-sub {
      color: var(--gray-light);
      font-size: 1.1rem;
      margin-bottom: 48px;
    }
    
    /* ----- HERO 双栏 ----- */
    .hero-grid {
      display: flex;
      align-items: center;
      gap: 60px;
    }
    .hero-left {
      flex: 1;
    }
    .hero-right {
      flex: 1;
      display: flex;
      justify-content: center;
    }
    .hero-right img {
      border-radius: var(--radius-md);
      box-shadow: var(--shadow-card);
      width: 100%;
      height: auto;
      object-fit: cover;
    }
    .hero-title {
      font-size: 3.6rem;
      font-weight: 700;
      margin-bottom: 24px;
      color: var(--charcoal);
    }
    .hero-buttons {
      display: flex;
      gap: 16px;
      margin-top: 32px;
    }
    
    /* 亮点网格 2x3 不规则 */
    .highlights-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 2px;
      background: var(--border-light);
      border-radius: var(--radius-md);
      overflow: hidden;
    }
    .highlight-item {
      background: white;
      padding: 40px 28px;
      transition: background 0.2s;
      display: flex;
      flex-direction: column;
    }
    .highlight-item:nth-child(even) {
      background: #FEFCF9;
    }
    .highlight-icon {
      font-size: 2rem;
      color: var(--terracotta);
      margin-bottom: 20px;
    }
    
    /* 案例瀑布流 (Masonry 用 column-count) */
    .masonry {
      column-count: 3;
      column-gap: 24px;
    }
    .masonry-card {
      break-inside: avoid;
      margin-bottom: 24px;
      background: white;
      border-radius: var(--radius-sm);
      overflow: hidden;
      box-shadow: var(--shadow-card);
      transition: transform 0.3s, box-shadow 0.3s;
    }
    .masonry-card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-hover);
    }
    .masonry-card img {
      width: 100%;
      display: block;
    }
    .card-content {
      padding: 20px;
    }
    .card-tag {
      background: var(--terracotta);
      color: white;
      padding: 2px 10px;
      border-radius: 12px;
      font-size: 0.75rem;
      display: inline-block;
    }
    
    /* 方案对比卡片 */
    .solutions-cards {
      display: flex;
      gap: 24px;
    }
    .solution-card {
      flex:1;
      background: white;
      border-radius: var(--radius-md);
      padding: 32px;
      box-shadow: var(--shadow-card);
      border: 1px solid var(--border-light);
    }
    .solution-card.recommended {
      border: 2px solid var(--kelly-green);
      position: relative;
      background: #F4F9F5;
    }
    .badge-recommend {
      background: var(--kelly-green);
      color: white;
      padding: 4px 14px;
      border-radius: 16px;
      font-size: 0.8rem;
      position: absolute;
      top: -12px;
      right: 20px;
    }
    
    /* FAQ 手风琴 */
    .faq-item {
      border-bottom: 1px solid var(--border-light);
      padding: 20px 0;
      cursor: pointer;
      transition: 0.2s;
    }
    .faq-question {
      font-weight: 600;
      display: flex;
      align-items: center;
      gap: 12px;
      font-size: 1.1rem;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease;
      color: var(--gray-text);
      margin-top: 0;
      padding-left: 24px;
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      margin-top: 16px;
    }
    
    /* CTA 横幅 */
    .cta-banner {
      background: var(--charcoal);
      border-radius: var(--radius-md);
      padding: 64px 32px;
      text-align: center;
      color: white;
    }
    
    /* 页脚 */
    .site-footer {
      background: var(--charcoal);
      color: #CCC;
      padding: 60px 0 30px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1.5fr;
      gap: 30px;
    }
    
    /* 响应式 */
    @media (max-width: 1024px) {
      .hero-grid { flex-direction: column; }
      .masonry { column-count: 2; }
    }
    @media (max-width: 768px) {
      .nav-links, .nav-right .search-box { display: none; }
      .menu-toggle { display: block; }
      .highlights-grid { grid-template-columns: 1fr 1fr; }
      .solutions-cards { flex-direction: column; }
      .footer-grid { grid-template-columns: 1fr 1fr; }
      .hero-title { font-size: 2.8rem; }
      .section-title { font-size: 2rem; }
    }
    @media (max-width: 640px) {
      .masonry { column-count: 1; }
      .highlights-grid { grid-template-columns: 1fr; }
      .hero-buttons { flex-direction: column; align-items: flex-start; }
      .footer-grid { grid-template-columns: 1fr; }
    }