/* roulang page: index */
:root {
      --primary: #2B6F9C;
      --primary-deep: #1f5a7a;
      --accent: #F4A261;
      --bg: #FAFAFA;
      --surface: #FFFFFF;
      --text-main: #1A1A1A;
      --text-secondary: #5C5C5C;
      --text-muted: #8C8C8C;
      --border-light: #E8ECF0;
      --shadow-sm: 0 4px 12px rgba(0,0,0,0.04);
      --shadow-md: 0 8px 24px rgba(0,0,0,0.06);
      --shadow-lg: 0 12px 32px rgba(0,0,0,0.08);
      --radius-sm: 8px;
      --radius-md: 12px;
      --radius-lg: 16px;
      --transition: 0.25s ease;
    }

    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }

    body {
      font-family: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", system-ui, -apple-system, sans-serif;
      background-color: var(--bg);
      color: var(--text-main);
      line-height: 1.5;
      -webkit-font-smoothing: antialiased;
    }

    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 24px;
    }

    @media (max-width: 480px) {
      .container {
        padding: 0 16px;
      }
    }

    /* 透明玻璃导航 */
    .glass-nav {
      background: rgba(255,255,255,0.75);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
      border-bottom: 1px solid var(--border-light);
      box-shadow: 0 2px 8px rgba(0,0,0,0.04);
      transition: background 0.3s ease, box-shadow 0.3s ease;
    }

    .nav-scrolled {
      background: rgba(255,255,255,0.98);
      backdrop-filter: blur(8px);
      -webkit-backdrop-filter: blur(8px);
      box-shadow: 0 4px 12px rgba(0,0,0,0.06);
    }

    .nav-link {
      color: var(--text-secondary);
      font-weight: 500;
      transition: color 0.2s;
      position: relative;
    }
    .nav-link:hover {
      color: var(--primary);
    }

    .btn-primary {
      background: var(--primary);
      color: white;
      font-weight: 600;
      border-radius: 8px;
      padding: 12px 28px;
      transition: all 0.25s ease;
      box-shadow: 0 4px 10px rgba(43,111,156,0.2);
      display: inline-block;
      text-align: center;
    }
    .btn-primary:hover {
      background: var(--primary-deep);
      transform: translateY(-2px);
      box-shadow: 0 8px 18px rgba(43,111,156,0.25);
    }

    .btn-outline {
      background: transparent;
      border: 1.5px solid var(--primary);
      color: var(--primary);
      font-weight: 600;
      border-radius: 8px;
      padding: 12px 28px;
      transition: all 0.25s ease;
      display: inline-block;
      text-align: center;
    }
    .btn-outline:hover {
      background: rgba(43,111,156,0.08);
      border-color: var(--primary-deep);
      color: var(--primary-deep);
      transform: translateY(-2px);
    }

    .card-hover {
      transition: all 0.3s ease;
      box-shadow: var(--shadow-sm);
    }
    .card-hover:hover {
      box-shadow: var(--shadow-md);
      transform: translateY(-4px);
    }

    /* 自定义表单样式 */
    .input-field {
      background: #F7F9FB;
      border: none;
      border-bottom: 2px solid #D1D9E0;
      border-radius: 6px 6px 0 0;
      padding: 14px 16px;
      font-size: 16px;
      transition: 0.2s;
      width: 100%;
      outline: none;
    }
    .input-field:focus {
      border-bottom: 3px solid var(--accent);
      background: #FFFFFF;
    }

    .faq-item {
      border-bottom: 1px solid var(--border-light);
    }
    .faq-question {
      cursor: pointer;
      transition: background 0.2s;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s ease, padding 0.25s;
      background: #F7F9FB;
      border-radius: 0 0 8px 8px;
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      padding: 16px 20px;
    }

    /* 瀑布流模拟 */
    .masonry-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    @media (max-width: 768px) {
      .masonry-grid {
        grid-template-columns: repeat(2, 1fr);
      }
    }
    @media (max-width: 640px) {
      .masonry-grid {
        grid-template-columns: 1fr;
      }
    }
    .case-card img {
      transition: transform 0.3s ease;
    }
    .case-card:hover img {
      transform: scale(1.03);
    }
    .case-card:hover .image-overlay {
      opacity: 0.3;
    }
    .image-overlay {
      background: rgba(43,111,156,0.2);
      position: absolute;
      top:0;left:0;right:0;bottom:0;
      opacity: 0;
      transition: opacity 0.3s;
    }

    /* 汉堡菜单 */
    .mobile-menu {
      background: rgba(255,255,255,0.96);
      backdrop-filter: blur(16px);
    }