/* roulang page: index */
/* 设计变量与全局重置 */
    :root {
      --primary: #1A1A2E;
      --secondary: #E8D5B7;
      --accent: #C9A96E;
      --bg: #F9F7F4;
      --text: #2C2C2C;
      --text-light: #5A5A5A;
      --footer-bg: #1A1A2E;
      --footer-text: #D0D0D0;
      --card-bg: #FDFBF7;
      --border-light: #E8D5B7;
      --shadow-sm: 0 2px 8px rgba(0,0,0,0.04);
      --shadow-md: 0 8px 24px rgba(0,0,0,0.08);
      --radius-card: 8px;
      --radius-btn: 6px;
      --radius-input: 4px;
      --font-sans: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", sans-serif;
    }
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }
    body {
      font-family: var(--font-sans);
      background-color: var(--bg);
      color: var(--text);
      line-height: 1.8;
      font-size: 16px;
      font-weight: 400;
      -webkit-font-smoothing: antialiased;
    }
    a {
      text-decoration: none;
      color: inherit;
      transition: color 0.15s ease;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    button, input, textarea {
      font-family: inherit;
    }
    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 32px;
    }
    @media (max-width: 768px) {
      .container {
        padding: 0 24px;
      }
    }
    @media (max-width: 480px) {
      .container {
        padding: 0 16px;
      }
    }
    /* 导航栏样式 */
    .nav-link {
      color: var(--text-light);
      font-size: 15px;
      font-weight: 400;
      position: relative;
      padding: 4px 0;
      transition: color 0.2s ease;
    }
    .nav-link:hover {
      color: var(--accent);
    }
    .nav-link.active {
      color: var(--primary);
      font-weight: 500;
    }
    .nav-link.active::after {
      content: '';
      position: absolute;
      left: 0;
      bottom: -4px;
      width: 100%;
      height: 2px;
      background-color: var(--accent);
    }
    /* 移动端汉堡菜单 */
    .mobile-menu {
      transition: max-height 0.3s ease;
      max-height: 0;
      overflow: hidden;
    }
    .mobile-menu.open {
      max-height: 300px;
    }
    /* 按钮样式 */
    .btn-primary {
      background-color: var(--primary);
      color: white;
      border-radius: var(--radius-btn);
      padding: 12px 28px;
      font-weight: 500;
      font-size: 15px;
      letter-spacing: 0.5px;
      display: inline-block;
      transition: background-color 0.2s ease;
      border: none;
      cursor: pointer;
    }
    .btn-primary:hover {
      background-color: #2D2D44;
    }
    .btn-secondary {
      background: transparent;
      border: 1px solid var(--accent);
      color: var(--primary);
      border-radius: var(--radius-btn);
      padding: 12px 28px;
      font-weight: 500;
      font-size: 15px;
      letter-spacing: 0.5px;
      display: inline-block;
      transition: background-color 0.2s ease;
    }
    .btn-secondary:hover {
      background-color: var(--secondary);
    }
    .text-link {
      color: var(--accent);
      font-weight: 500;
      transition: color 0.15s, border-bottom 0.15s;
      border-bottom: 1px solid transparent;
    }
    .text-link:hover {
      color: #b08a4a;
      border-bottom: 1px solid #b08a4a;
    }
    /* 卡片交互 */
    .feature-card {
      background-color: var(--card-bg);
      border-radius: var(--radius-card);
      padding: 32px 24px;
      transition: box-shadow 0.2s ease;
      box-shadow: var(--shadow-sm);
    }
    .feature-card:hover {
      box-shadow: var(--shadow-md);
    }
    .case-card {
      background: white;
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
      transition: transform 0.2s ease, box-shadow 0.2s ease;
    }
    .case-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-md);
    }
    .case-card img {
      transition: transform 0.3s ease;
    }
    .case-card:hover img {
      transform: scale(1.03);
    }
    /* FAQ 手风琴 */
    .faq-item {
      border-bottom: 1px solid var(--border-light);
      padding: 18px 0;
    }
    .faq-question {
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-weight: 500;
      font-size: 18px;
      color: var(--primary);
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease, padding 0.3s ease;
      color: var(--text-light);
      font-weight: 300;
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      padding-top: 16px;
    }
    .faq-icon {
      color: var(--accent);
      transition: transform 0.2s ease;
    }
    .faq-item.active .faq-icon {
      transform: rotate(180deg);
    }
    /* 输入框 */
    input, textarea {
      background: white;
      border: 1px solid var(--border-light);
      border-radius: var(--radius-input);
      padding: 12px;
      width: 100%;
      font-size: 15px;
      transition: border-color 0.2s;
    }
    input:focus, textarea:focus {
      outline: none;
      border-color: var(--accent);
    }
    /* 标签 */
    .tag {
      background-color: var(--secondary);
      color: var(--primary);
      font-size: 13px;
      padding: 4px 12px;
      border-radius: 20px;
      font-weight: 500;
      display: inline-block;
    }
    /* 页脚链接 */
    .footer-link {
      color: var(--footer-text);
      transition: color 0.2s;
    }
    .footer-link:hover {
      color: var(--accent);
    }
    /* 响应式调整 */
    @media (max-width: 768px) {
      h1 { font-size: 36px; line-height: 1.3; }
      h2 { font-size: 28px; }
      .hero-grid {
        flex-direction: column;
      }
    }
    @media (max-width: 480px) {
      h1 { font-size: 28px; }
      h2 { font-size: 24px; }
      .btn-primary, .btn-secondary {
        padding: 10px 20px;
        font-size: 14px;
      }
    }