/* roulang page: index */
:root {
      --primary: #0B3B36;
      --primary-light: #1A5B54;
      --accent: #C9A96E;
      --accent-light: #DEC07A;
      --bg-warm: #FAF9F7;
      --card-bg: #FFFFFF;
      --dark-bg: #0A2E2B;
      --text-main: #2D2D2D;
      --text-secondary: #6B6B6B;
      --text-on-dark: #FFFFFF;
      --text-warm: #E8E0D5;
      --border-soft: #EBE7E0;
      --shadow-card: 0 2px 8px rgba(0,0,0,0.04);
      --shadow-hover: 0 8px 24px rgba(11,59,54,0.12);
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-chip: 20px;
      --font-serif: 'Noto Serif SC', 'Source Han Serif SC', serif;
      --font-sans: 'Inter', 'Noto Sans SC', system-ui, -apple-system, sans-serif;
    }
    * {
      box-sizing: border-box;
    }
    body {
      margin: 0;
      font-family: var(--font-sans);
      background-color: var(--bg-warm);
      color: var(--text-main);
      line-height: 1.7;
      -webkit-font-smoothing: antialiased;
    }
    h1, h2, h3 {
      font-family: var(--font-serif);
      margin: 0;
      font-weight: 600;
    }
    h1 {
      font-size: 48px;
      line-height: 56px;
      color: var(--primary);
    }
    h2 {
      font-size: 36px;
      line-height: 44px;
      color: var(--primary);
      margin-bottom: 1.5rem;
    }
    h3 {
      font-size: 22px;
      line-height: 30px;
      color: var(--primary);
    }
    p {
      color: var(--text-secondary);
      margin: 0;
    }
    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 2rem;
    }
    .section-padding {
      padding: 5rem 0;
    }
    .btn-primary {
      background-color: var(--primary);
      color: white;
      padding: 12px 28px;
      border-radius: var(--radius-btn);
      font-weight: 500;
      border: none;
      cursor: pointer;
      transition: all 0.2s ease;
      display: inline-block;
      text-decoration: none;
      font-family: var(--font-sans);
    }
    .btn-primary:hover {
      background-color: #0F4A43;
      transform: translateY(-2px);
      box-shadow: 0 4px 12px rgba(11,59,54,0.3);
    }
    .btn-outline {
      background: transparent;
      border: 1.5px solid var(--primary);
      color: var(--primary);
      padding: 12px 28px;
      border-radius: var(--radius-btn);
      font-weight: 500;
      cursor: pointer;
      transition: all 0.2s ease;
      display: inline-block;
      text-decoration: none;
      font-family: var(--font-sans);
    }
    .btn-outline:hover {
      background-color: rgba(11,59,54,0.08);
      transform: translateY(-2px);
    }
    .card {
      background: var(--card-bg);
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-card);
      border: 1px solid var(--border-soft);
      transition: all 0.25s ease;
    }
    .card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
      border-color: var(--accent);
    }
    .chip {
      border-radius: var(--radius-chip);
      padding: 6px 16px;
      font-size: 15px;
      background: transparent;
      color: #6B6B6B;
      border: none;
      cursor: pointer;
      transition: all 0.2s;
      white-space: nowrap;
    }
    .chip.active {
      background-color: rgba(11,59,54,0.1);
      color: var(--primary);
      border-bottom: 2px solid var(--accent);
      font-weight: 500;
    }
    .chip:hover:not(.active) {
      background-color: rgba(0,0,0,0.03);
      color: var(--primary);
    }
    /* 移动端底部导航 */
    .mobile-bottom-nav {
      display: none;
    }
    /* 瀑布流杂志风格 */
    .masonry-grid {
      columns: 2;
      column-gap: 24px;
    }
    .masonry-item {
      break-inside: avoid;
      margin-bottom: 24px;
      transition: transform 0.2s;
    }
    .masonry-item img {
      transition: transform 0.3s;
      border-radius: 12px;
      width: 100%;
      display: block;
    }
    .masonry-item:hover img {
      transform: scale(1.02);
    }
    /* 对比表高亮列 */
    .highlight-col {
      background-color: rgba(11,59,54,0.04);
      border-left: 3px solid var(--accent);
    }
    /* FAQ箭头动画 */
    .faq-arrow {
      transition: transform 0.3s;
    }
    details[open] .faq-arrow {
      transform: rotate(180deg);
    }
    @media (max-width: 1024px) {
      h1 {
        font-size: 40px;
        line-height: 48px;
      }
      .masonry-grid {
        columns: 1;
      }
    }
    @media (max-width: 768px) {
      h1 {
        font-size: 32px;
        line-height: 40px;
      }
      h2 {
        font-size: 28px;
      }
      .container {
        padding: 0 1.5rem;
      }
      .section-padding {
        padding: 3.5rem 0;
      }
      .desktop-nav-chips {
        display: none;
      }
      .mobile-bottom-nav {
        display: flex;
        position: fixed;
        bottom: 0;
        left: 0;
        right: 0;
        background: rgba(255,255,255,0.96);
        backdrop-filter: blur(8px);
        border-top: 1px solid var(--border-soft);
        justify-content: space-around;
        padding: 0.75rem 0.5rem;
        z-index: 40;
        box-shadow: 0 -2px 10px rgba(0,0,0,0.04);
      }
      .mobile-bottom-nav a {
        font-size: 12px;
        color: var(--text-secondary);
        display: flex;
        flex-direction: column;
        align-items: center;
        gap: 4px;
        text-decoration: none;
        font-weight: 500;
      }
      .mobile-bottom-nav a.active {
        color: var(--primary);
      }
      .hero-image {
        margin-top: 2rem;
      }
      .footer-grid {
        grid-template-columns: repeat(2, 1fr);
      }
    }
    @media (max-width: 520px) {
      .container {
        padding: 0 1rem;
      }
      .footer-grid {
        grid-template-columns: 1fr;
      }
      .btn-group {
        flex-direction: column;
        align-items: flex-start;
      }
    }