/* roulang page: index */
:root {
      --sky-blue: #2E86DE;
      --energy-orange: #FF6B35;
      --grass-green: #27AE60;
      --bg-light: #F9FAFB;
      --bg-sky-light: #EBF5FB;
      --text-main: #1E293B;
      --text-muted: #64748B;
      --border-light: #E2E8F0;
      --card-shadow: 0 4px 16px rgba(0,0,0,0.06);
      --card-hover-shadow: 0 8px 24px rgba(0,0,0,0.10);
      --radius-md: 12px;
      --radius-btn: 8px;
    }
    * {
      box-sizing: border-box;
    }
    body {
      margin: 0;
      font-family: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", sans-serif;
      background-color: var(--bg-light);
      color: var(--text-main);
      line-height: 1.7;
      -webkit-font-smoothing: antialiased;
    }
    .container {
      max-width: 1280px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 1.5rem;
      padding-right: 1.5rem;
    }
    /* 导航系统 */
    .navbar {
      background: white;
      border-bottom: 1px solid var(--border-light);
      position: sticky;
      top: 0;
      z-index: 50;
    }
    .nav-brand {
      font-weight: 700;
      font-size: 1.5rem;
      color: var(--sky-blue);
      display: flex;
      align-items: center;
      gap: 0.5rem;
    }
    .nav-link {
      font-size: 0.95rem;
      font-weight: 500;
      color: var(--text-main);
      padding: 0.5rem 1rem;
      border-radius: 8px;
      transition: all 0.2s ease;
    }
    .nav-link:hover {
      color: var(--sky-blue);
      background-color: #f1f5f9;
    }
    .mobile-menu {
      display: none;
    }
    /* 按钮系统 */
    .btn-primary {
      background-color: var(--energy-orange);
      color: white;
      font-weight: 600;
      padding: 0.75rem 2rem;
      border-radius: var(--radius-btn);
      border: none;
      cursor: pointer;
      transition: all 0.2s ease;
      display: inline-block;
      text-align: center;
      box-shadow: 0 2px 8px rgba(255,107,53,0.2);
    }
    .btn-primary:hover {
      filter: brightness(0.9);
      box-shadow: 0 4px 14px rgba(255,107,53,0.35);
      transform: translateY(-1px);
    }
    .btn-outline {
      background: transparent;
      border: 2px solid var(--sky-blue);
      color: var(--sky-blue);
      font-weight: 600;
      padding: 0.75rem 2rem;
      border-radius: var(--radius-btn);
      transition: all 0.2s ease;
      display: inline-block;
      text-align: center;
    }
    .btn-outline:hover {
      background-color: #EBF5FB;
    }
    /* 卡片 */
    .card {
      background: white;
      border-radius: var(--radius-md);
      box-shadow: var(--card-shadow);
      transition: all 0.25s ease;
    }
    .card:hover {
      box-shadow: var(--card-hover-shadow);
      transform: translateY(-4px);
    }
    /* 板块 */
    .section-padding {
      padding: 5rem 0;
    }
    .bg-alternate {
      background-color: #EBF5FB;
    }
    .h2-title {
      font-size: 2.25rem;
      font-weight: 700;
      line-height: 1.3;
      margin-bottom: 1rem;
    }
    .h3-title {
      font-size: 1.25rem;
      font-weight: 700;
      line-height: 1.5;
    }
    .text-muted-para {
      color: var(--text-muted);
      font-size: 1rem;
    }
    /* 手风琴 */
    .faq-item {
      border-bottom: 1px solid var(--border-light);
    }
    .faq-question {
      cursor: pointer;
      padding: 1.2rem 0;
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-weight: 600;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease, padding 0.3s ease;
      color: var(--text-muted);
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      padding-bottom: 1.5rem;
    }
    .faq-item.active .faq-question i {
      transform: rotate(180deg);
      color: var(--sky-blue);
    }
    /* 移动端断点 */
    @media (max-width: 768px) {
      .desktop-menu {
        display: none;
      }
      .mobile-menu-btn {
        display: block;
      }
      .mobile-menu {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        width: 100%;
        background: white;
        border-top: 1px solid var(--border-light);
        box-shadow: 0 8px 24px rgba(0,0,0,0.08);
        flex-direction: column;
        padding: 1rem 1.5rem;
      }
      .mobile-menu.open {
        display: flex;
      }
      .h2-title {
        font-size: 1.8rem;
      }
      .card:hover {
        transform: none;
      }
      .hero-image {
        height: 220px;
        width: 100%;
        object-fit: cover;
        border-radius: 16px;
        margin-top: 2rem;
      }
    }
    @media (min-width: 769px) {
      .mobile-menu-btn, .mobile-menu {
        display: none;
      }
      .desktop-menu {
        display: flex;
        align-items: center;
        gap: 0.4rem;
      }
    }
    .footer-link {
      color: #CBD5E1;
      transition: color 0.2s;
    }
    .footer-link:hover {
      color: white;
    }