/* roulang page: index */
:root {
      --deep-plum: #3A2C3F;
      --champagne-gold: #C9A96E;
      --amber-orange: #D4793A;
      --warm-gray-bg: #F7F5F2;
      --charcoal: #2B2B2B;
      --dark-gray: #5A5A5A;
      --light-champagne: #E5D5C0;
      --soft-white: #FCFAF7;
      --card-shadow: 0 2px 12px rgba(58,44,63,0.08);
      --card-hover-shadow: 0 8px 24px rgba(58,44,63,0.15);
      --border-color: #E5D5C0;
      --radius-card: 8px;
      --radius-btn: 6px;
      --radius-tag: 4px;
      --transition: 0.25s ease;
    }
    * {
      box-sizing: border-box;
    }
    body {
      font-family: 'PingFang SC', 'Microsoft YaHei', 'Noto Sans SC', system-ui, -apple-system, sans-serif;
      background-color: var(--warm-gray-bg);
      color: var(--charcoal);
      line-height: 1.75;
      margin: 0;
      -webkit-font-smoothing: antialiased;
    }
    h1, h2, h3, .serif-title {
      font-family: 'Noto Serif SC', 'Times New Roman', '宋体', serif;
      letter-spacing: -0.01em;
      line-height: 1.25;
      color: var(--deep-plum);
    }
    .section-title {
      font-size: 2rem;
      font-weight: 600;
      margin-bottom: 1.5rem;
      position: relative;
      display: inline-block;
    }
    .section-title::after {
      content: '';
      position: absolute;
      bottom: -8px;
      left: 0;
      width: 48px;
      height: 3px;
      background: var(--champagne-gold);
    }
    .container-custom {
      max-width: 1280px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 1.5rem;
      padding-right: 1.5rem;
    }
    /* 导航 */
    .nav-glass {
      background: rgba(247, 245, 242, 0.85);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
      transition: background 0.3s, box-shadow 0.3s;
    }
    .nav-scrolled {
      background: rgba(247, 245, 242, 0.98);
      box-shadow: 0 4px 20px rgba(0,0,0,0.05);
    }
    .nav-link {
      color: var(--deep-plum);
      font-weight: 500;
      position: relative;
      padding: 0.25rem 0;
      transition: color 0.2s;
    }
    .nav-link::after {
      content: '';
      position: absolute;
      bottom: -2px;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--champagne-gold);
      transition: width 0.25s;
    }
    .nav-link:hover {
      color: var(--champagne-gold);
    }
    .nav-link:hover::after {
      width: 100%;
    }
    .btn-primary {
      background: var(--champagne-gold);
      color: var(--deep-plum);
      border-radius: var(--radius-btn);
      padding: 0.6rem 1.8rem;
      font-weight: 600;
      transition: background 0.25s, transform 0.2s;
      border: none;
      cursor: pointer;
    }
    .btn-primary:hover {
      background: #b8934f;
    }
    .btn-outline {
      background: transparent;
      border: 1.5px solid var(--deep-plum);
      color: var(--deep-plum);
      border-radius: var(--radius-btn);
      padding: 0.6rem 1.8rem;
      font-weight: 500;
      transition: all 0.25s;
    }
    .btn-outline:hover {
      background: var(--light-champagne);
      border-color: var(--champagne-gold);
    }
    .btn-cta {
      background: var(--amber-orange);
      color: white;
      border-radius: var(--radius-btn);
      padding: 0.7rem 2rem;
      font-weight: 600;
      transition: background 0.25s, transform 0.2s;
      box-shadow: 0 4px 10px rgba(212,121,58,0.3);
    }
    .btn-cta:hover {
      background: #c0682e;
      transform: scale(1.03);
    }
    /* 卡片 */
    .service-card {
      background: white;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-card);
      padding: 1.8rem;
      box-shadow: var(--card-shadow);
      transition: all 0.25s;
    }
    .service-card:hover {
      box-shadow: var(--card-hover-shadow);
      transform: translateY(-4px);
      border-color: var(--champagne-gold);
    }
    .case-card {
      background: white;
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--card-shadow);
      transition: all 0.25s;
      border: 1px solid var(--border-color);
    }
    .case-card:hover {
      box-shadow: var(--card-hover-shadow);
      transform: translateY(-4px);
    }
    .case-card img {
      transition: transform 0.4s;
    }
    .case-card:hover img {
      transform: scale(1.03);
    }
    /* FAQ */
    .faq-item {
      border-bottom: 1px solid var(--light-champagne);
    }
    .faq-question {
      cursor: pointer;
      padding: 1rem 0;
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-weight: 600;
      color: var(--deep-plum);
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s ease, padding 0.35s;
      background: #FCFAF7;
      border-radius: 0 0 6px 6px;
      color: var(--dark-gray);
      line-height: 1.7;
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      padding: 1rem 1rem 1rem 0;
    }
    .faq-icon {
      font-size: 1.5rem;
      color: var(--champagne-gold);
      transition: transform 0.25s;
    }
    .faq-item.active .faq-icon {
      transform: rotate(45deg);
    }
    /* 表单 */
    input, textarea {
      background: #fff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-btn);
      padding: 0.75rem 1rem;
      width: 100%;
      transition: border 0.2s;
      font-family: inherit;
    }
    input:focus, textarea:focus {
      outline: none;
      border-color: var(--champagne-gold);
      box-shadow: 0 0 0 3px rgba(201,169,110,0.15);
    }
    /* 装饰线条 */
    .golden-line {
      height: 1px;
      background: linear-gradient(to right, transparent, var(--champagne-gold), transparent);
      width: 80px;
      margin: 0.5rem 0 1rem;
    }
    @media (max-width: 768px) {
      .section-title {
        font-size: 1.8rem;
      }
      .hero-left {
        text-align: center;
        padding: 2rem 1rem;
      }
    }
    footer a:hover {
      color: var(--champagne-gold);
    }
    /* 汉堡菜单动画 */
    .mobile-menu {
      transition: transform 0.3s ease, opacity 0.3s;
      transform: translateX(100%);
    }
    .mobile-menu.open {
      transform: translateX(0);
    }