/* roulang page: index */
:root {
      --primary: #D49B3B;
      --primary-hover: #B8842E;
      --primary-light: rgba(212, 155, 59, 0.08);
      --secondary: #5F6B5C;
      --bg: #F9F6F0;
      --dark: #1E1E1E;
      --text: #2C2C2C;
      --text-light: #5A5A5A;
      --white: #FFFFFF;
      --border-light: rgba(0,0,0,0.04);
      --shadow-sm: 0 4px 12px rgba(0,0,0,0.04);
      --shadow-md: 0 8px 24px rgba(0,0,0,0.08);
      --radius-card: 12px;
      --radius-btn: 8px;
      --transition: 0.25s ease;
    }
    * {
      box-sizing: border-box;
    }
    body {
      margin: 0;
      font-family: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", "WenQuanYi Micro Hei", sans-serif;
      background-color: var(--bg);
      color: var(--text);
      line-height: 1.7;
      -webkit-font-smoothing: antialiased;
    }
    img {
      display: block;
      max-width: 100%;
      height: auto;
    }
    a {
      text-decoration: none;
      color: inherit;
    }
    button, .btn {
      cursor: pointer;
      font-family: inherit;
      transition: var(--transition);
      border: none;
      outline: none;
    }
    .container {
      max-width: 1280px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 1.5rem;
      padding-right: 1.5rem;
    }
    h1, h2, h3, h4 {
      font-weight: 700;
      letter-spacing: -0.02em;
      line-height: 1.2;
      color: #1A1A1A;
      margin: 0;
    }
    p {
      margin: 0;
      max-width: 68ch;
    }
    .section-padding {
      padding-top: 4rem;
      padding-bottom: 4rem;
    }
    @media (min-width: 768px) {
      .section-padding {
        padding-top: 6rem;
        padding-bottom: 6rem;
      }
    }
    /* 导航 */
    .nav-link {
      position: relative;
      font-size: 0.95rem;
      color: var(--dark);
      transition: color var(--transition);
      white-space: nowrap;
    }
    .nav-link::after {
      content: '';
      position: absolute;
      left: 50%;
      bottom: -4px;
      width: 0;
      height: 2px;
      background-color: var(--primary);
      transition: width 0.2s ease, left 0.2s ease;
      transform: translateX(-50%);
    }
    .nav-link:hover {
      color: var(--primary);
    }
    .nav-link:hover::after {
      width: 100%;
      left: 50%;
    }
    /* 汉堡菜单 */
    .hamburger-line {
      display: block;
      width: 24px;
      height: 2px;
      background-color: var(--primary);
      margin: 5px 0;
      transition: 0.25s;
    }
    .mobile-menu {
      display: none;
      position: fixed;
      top: 64px;
      left: 0;
      width: 100%;
      background: var(--white);
      box-shadow: var(--shadow-md);
      z-index: 40;
      flex-direction: column;
      padding: 1.5rem 1rem;
      gap: 1.25rem;
    }
    .mobile-menu.open {
      display: flex;
    }
    /* 卡片 */
    .card {
      background: var(--white);
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-sm);
      border: 1px solid var(--border-light);
      transition: var(--transition);
    }
    .card:hover {
      box-shadow: var(--shadow-md);
      transform: translateY(-4px);
    }
    .service-icon {
      width: 64px;
      height: 64px;
      border-radius: 50%;
      border: 2px solid var(--primary);
      background-color: #faf7f2;
      display: flex;
      align-items: center;
      justify-content: center;
      overflow: hidden;
      transition: var(--transition);
    }
    .card:hover .service-icon {
      border-color: var(--primary);
      background-color: var(--primary-light);
    }
    .case-img-wrapper {
      border-radius: var(--radius-card) var(--radius-card) 0 0;
      overflow: hidden;
    }
    .case-img-wrapper img {
      transition: transform 0.4s ease;
      width: 100%;
      height: auto;
    }
    .card:hover .case-img-wrapper img {
      transform: scale(1.03);
    }
    /* 手风琴 */
    .faq-item {
      border: 1px solid var(--border-light);
      border-radius: var(--radius-card);
      background: var(--white);
      margin-bottom: 0.75rem;
      transition: var(--transition);
    }
    .faq-item.active {
      border-color: var(--primary);
    }
    .faq-question {
      display: flex;
      justify-content: space-between;
      align-items: center;
      padding: 1rem 1.5rem;
      font-weight: 600;
      cursor: pointer;
      color: #1A1A1A;
      background: transparent;
      width: 100%;
      text-align: left;
      border: none;
      font-size: 1rem;
    }
    .faq-icon {
      font-size: 1.5rem;
      color: var(--secondary);
      transition: transform 0.2s;
      font-weight: 400;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease, padding 0.3s ease;
      background-color: #f7f5f0;
      padding: 0 1.5rem;
      color: var(--text);
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      padding: 1rem 1.5rem;
    }
    /* 按钮 */
    .btn-primary {
      background-color: var(--primary);
      color: white;
      border-radius: var(--radius-btn);
      padding: 0.75rem 2rem;
      font-weight: 600;
      display: inline-block;
      text-align: center;
      transition: var(--transition);
      border: 2px solid transparent;
    }
    .btn-primary:hover {
      background-color: var(--primary-hover);
      transform: translateY(-1px);
    }
    .btn-outline {
      background: transparent;
      border: 2px solid var(--primary);
      color: var(--primary);
      border-radius: var(--radius-btn);
      padding: 0.75rem 2rem;
      font-weight: 600;
      display: inline-block;
      text-align: center;
      transition: var(--transition);
    }
    .btn-outline:hover {
      background-color: var(--primary-light);
      transform: translateY(-1px);
    }
    footer {
      background-color: var(--dark);
      color: #cccccc;
    }