/* roulang page: index */
:root {
      --primary: #0B3B2F;
      --primary-hover: #0D4A3A;
      --accent: #D4A84B;
      --bg-light: #F9F9F6;
      --bg-card: #FFFFFF;
      --bg-soft: #E8F0ED;
      --text-main: #1A1A1A;
      --text-muted: #5C5C5C;
      --text-link: #0B3B2F;
      --border-light: #E0E0E0;
      --shadow-sm: 0 1px 8px rgba(0,0,0,0.04);
      --shadow-card: 0 4px 20px rgba(0,0,0,0.03);
      --shadow-card-hover: 0 12px 30px rgba(0,0,0,0.08);
      --radius-sm: 8px;
      --radius-md: 16px;
      --font-serif: 'Noto Serif SC', 'Georgia', 'Times New Roman', serif;
      --font-sans: 'Inter', 'DM Sans', 'PingFang SC', 'Microsoft YaHei', sans-serif;
    }
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }
    body {
      font-family: var(--font-sans);
      background-color: var(--bg-light);
      color: var(--text-main);
      line-height: 1.7;
      -webkit-font-smoothing: antialiased;
      scroll-behavior: smooth;
    }
    h1, h2, h3, .serif {
      font-family: var(--font-serif);
      font-weight: 600;
      letter-spacing: -0.02em;
    }
    .container {
      max-width: 1280px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 24px;
      padding-right: 24px;
    }
    /* 导航 */
    .main-header {
      position: sticky;
      top: 0;
      z-index: 50;
      background: white;
      box-shadow: var(--shadow-sm);
      height: 68px;
      display: flex;
      align-items: center;
    }
    .nav-logo {
      font-family: var(--font-serif);
      font-weight: 700;
      font-size: 22px;
      color: var(--primary);
      display: flex;
      align-items: center;
      gap: 8px;
      text-decoration: none;
    }
    .nav-link {
      font-size: 15px;
      color: var(--text-muted);
      text-decoration: none;
      transition: color 0.2s;
      font-weight: 500;
    }
    .nav-link:hover {
      color: var(--primary);
    }
    .search-box {
      border: 1px solid var(--border-light);
      border-radius: 24px;
      padding: 6px 16px;
      font-size: 14px;
      outline: none;
      transition: border 0.2s, box-shadow 0.2s;
      background: white;
      width: 160px;
    }
    .search-box:focus {
      border-color: var(--primary);
      box-shadow: 0 0 0 3px rgba(11,59,47,0.1);
    }
    .btn-primary {
      background: var(--primary);
      color: white;
      border-radius: var(--radius-sm);
      padding: 12px 28px;
      font-weight: 600;
      transition: all 0.25s;
      display: inline-block;
      text-decoration: none;
      border: none;
      cursor: pointer;
      box-shadow: 0 2px 6px rgba(0,0,0,0.05);
    }
    .btn-primary:hover {
      background: var(--primary-hover);
      transform: translateY(-2px);
      box-shadow: 0 8px 18px rgba(11,59,47,0.2);
    }
    .btn-accent {
      background: var(--accent);
      color: white;
      border-radius: var(--radius-sm);
      padding: 12px 28px;
      font-weight: 600;
      transition: all 0.25s;
      display: inline-block;
      text-decoration: none;
      border: none;
    }
    .btn-accent:hover {
      background: #c99a3a;
      transform: translateY(-2px);
    }
    .btn-outline {
      border: 2px solid var(--primary);
      background: transparent;
      color: var(--primary);
      border-radius: var(--radius-sm);
      padding: 12px 28px;
      font-weight: 600;
      transition: all 0.25s;
      display: inline-block;
      text-decoration: none;
    }
    .btn-outline:hover {
      background: var(--bg-soft);
      transform: translateY(-2px);
    }
    /* 卡片 */
    .card-soft {
      background: var(--bg-soft);
      border-radius: var(--radius-md);
      padding: 28px;
      transition: all 0.3s;
      box-shadow: none;
    }
    .card-white {
      background: white;
      border-radius: var(--radius-md);
      box-shadow: var(--shadow-card);
      transition: all 0.3s;
      overflow: hidden;
    }
    .card-white:hover {
      box-shadow: var(--shadow-card-hover);
      transform: translateY(-4px);
    }
    .cover-img-wrapper {
      overflow: hidden;
      position: relative;
    }
    .cover-img-wrapper img {
      transition: transform 0.4s ease;
      width: 100%;
      height: auto;
      display: block;
      aspect-ratio: 16 / 9;
      object-fit: cover;
    }
    .card-white:hover .cover-img-wrapper img {
      transform: scale(1.05);
    }
    /* FAQ 手风琴 */
    .faq-item {
      border-bottom: 1px solid rgba(0,0,0,0.05);
      transition: background 0.2s;
    }
    .faq-question {
      width: 100%;
      background: transparent;
      border: none;
      padding: 20px 0;
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-weight: 600;
      font-size: 18px;
      color: var(--text-main);
      cursor: pointer;
      text-align: left;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s ease, padding 0.35s ease;
      color: var(--text-muted);
      padding: 0 0;
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      padding-bottom: 20px;
    }
    .faq-icon {
      transition: transform 0.3s;
      font-size: 20px;
      color: var(--primary);
    }
    .faq-item.active .faq-icon {
      transform: rotate(45deg);
    }
    /* 区块间距 */
    section {
      padding-top: 100px;
      padding-bottom: 100px;
    }
    @media (max-width: 768px) {
      section {
        padding-top: 70px;
        padding-bottom: 70px;
      }
      h1 {
        font-size: 32px !important;
      }
      h2 {
        font-size: 26px !important;
      }
      .nav-desktop {
        display: none !important;
      }
      .mobile-menu-btn {
        display: flex !important;
      }
    }
    .mobile-menu-btn {
      display: none;
      background: none;
      border: none;
      font-size: 24px;
      color: var(--primary);
    }
    .timeline-dot {
      width: 40px;
      height: 40px;
      background: var(--primary);
      color: white;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 700;
      font-size: 20px;
      margin: 0 auto 16px;
    }
    .dashed-line {
      border-top: 2px dashed var(--border-light);
      flex: 1;
      margin-top: 20px;
    }