/* roulang page: index */
:root {
      --primary: #1B5E20;
      --accent: #F57C00;
      --bg: #FAFAF5;
      --text: #2C2C2C;
      --text-light: #666666;
      --radius-card: 12px;
      --radius-btn: 8px;
      --shadow-card: 0 2px 12px rgba(44,44,44,0.06);
      --shadow-hover: 0 8px 24px rgba(27,94,32,0.12);
    }

    * {
      box-sizing: border-box;
    }

    body {
      font-family: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", sans-serif;
      background-color: #FAFAF5;
      color: #2C2C2C;
      line-height: 1.7;
      margin: 0;
      -webkit-font-smoothing: antialiased;
    }

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

    a {
      text-decoration: none;
      color: inherit;
      transition: color 0.2s ease;
    }

    button, .btn {
      cursor: pointer;
      font-family: inherit;
    }

    .container {
      max-width: 1280px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 24px;
      padding-right: 24px;
    }

    @media (max-width: 768px) {
      .container {
        padding-left: 16px;
        padding-right: 16px;
      }
    }

    /* 导航固定及阴影 */
    #navbar {
      transition: box-shadow 0.3s ease;
    }
    .nav-scrolled {
      box-shadow: 0 2px 12px rgba(0,0,0,0.06);
    }

    /* 汉堡菜单动画 */
    #mobile-menu {
      transition: opacity 0.3s ease, transform 0.3s ease;
      transform: translateY(-10px);
      opacity: 0;
      pointer-events: none;
    }
    #mobile-menu.open {
      transform: translateY(0);
      opacity: 1;
      pointer-events: auto;
    }

    /* 卡片hover效果 */
    .feature-card:hover, .case-card:hover {
      box-shadow: var(--shadow-hover);
      transform: translateY(-4px);
    }

    .feature-card {
      transition: all 0.25s ease;
      border-bottom: 3px solid transparent;
    }
    .feature-card:hover {
      border-bottom-color: #F57C00;
    }

    /* 按钮动效 */
    .btn-primary {
      background-color: #F57C00;
      color: white;
      border-radius: 8px;
      padding: 14px 32px;
      font-weight: 600;
      transition: all 0.25s ease;
      display: inline-block;
      text-align: center;
      border: none;
    }
    .btn-primary:hover {
      background-color: #E06B00;
      transform: translateY(-2px);
      box-shadow: 0 4px 12px rgba(245,124,0,0.3);
    }

    .btn-outline {
      background: transparent;
      border: 2px solid #1B5E20;
      color: #1B5E20;
      border-radius: 8px;
      padding: 12px 30px;
      font-weight: 600;
      transition: all 0.25s ease;
      display: inline-block;
      text-align: center;
    }
    .btn-outline:hover {
      background-color: #1B5E20;
      color: white;
      transform: translateY(-2px);
    }

    /* FAQ手风琴 */
    .faq-item {
      border-radius: 8px;
      background: #F0F5F0;
      margin-bottom: 12px;
      overflow: hidden;
    }
    .faq-question {
      padding: 18px 24px;
      font-weight: 600;
      display: flex;
      align-items: center;
      gap: 12px;
      cursor: pointer;
      user-select: none;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease, padding 0.3s ease;
      background: white;
      padding: 0 24px;
    }
    .faq-item.active .faq-answer {
      max-height: 300px;
      padding: 20px 24px;
    }

    /* 方案对比卡片 */
    .compare-traditional {
      background: #f0f0f0;
      border-left: 4px solid #999;
    }
    .compare-bird {
      background: #F0F5F0;
      border-left: 4px solid #1B5E20;
    }

    /* 案例瀑布基础 */
    .masonry-grid {
      column-count: 3;
      column-gap: 24px;
    }
    @media (max-width: 1024px) {
      .masonry-grid {
        column-count: 2;
      }
    }
    @media (max-width: 640px) {
      .masonry-grid {
        column-count: 1;
      }
    }
    .case-card {
      break-inside: avoid;
      margin-bottom: 24px;
      background: white;
      border-radius: 12px;
      overflow: hidden;
      box-shadow: 0 2px 12px rgba(0,0,0,0.04);
      transition: all 0.25s;
    }

    /* 装饰图形 */
    .hero-graphic {
      position: relative;
    }
    .hero-graphic::after {
      content: "";
      position: absolute;
      right: -20px;
      bottom: -20px;
      width: 180px;
      height: 180px;
      background: radial-gradient(circle at 30% 30%, rgba(27,94,32,0.08) 0%, transparent 70%);
      border-radius: 50%;
      z-index: 0;
    }

    @media (max-width: 768px) {
      .btn-primary, .btn-outline {
        width: 100%;
        text-align: center;
      }
    }