/* roulang page: index */
:root {
      --deep-blue: #0A1628;
      --gold: #C89B3C;
      --light-bg: #F4F7FA;
      --white: #FFFFFF;
      --text-primary: #1F2937;
      --text-secondary: #4B5563;
      --text-muted: #6B7280;
      --border-light: #E5E7EB;
      --shadow-card: 0 4px 12px rgba(10, 22, 40, 0.06);
      --shadow-card-hover: 0 8px 24px rgba(10, 22, 40, 0.12);
      --radius-card: 12px;
      --radius-button: 8px;
      --transition: all 0.3s ease;
      --nav-height: 72px;
    }

    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }

    body {
      font-family: 'Inter', 'PingFang SC', 'Microsoft YaHei', system-ui, -apple-system, sans-serif;
      background-color: var(--light-bg);
      color: var(--text-primary);
      line-height: 1.6;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }

    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 32px;
    }

    h1, h2, h3 {
      font-weight: 600;
      line-height: 1.3;
    }

    h1 {
      font-size: 48px;
      font-weight: 700;
    }

    h2 {
      font-size: 36px;
      margin-bottom: 16px;
    }

    h3 {
      font-size: 24px;
    }

    p {
      color: var(--text-secondary);
      font-weight: 400;
    }

    a {
      text-decoration: none;
      color: inherit;
      transition: var(--transition);
    }

    img {
      max-width: 100%;
      display: block;
    }

    button, .btn {
      cursor: pointer;
      font-family: inherit;
      border: none;
      background: none;
      font-weight: 500;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      transition: var(--transition);
    }

    /* 导航 */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: var(--nav-height);
      background: rgba(255, 255, 255, 0.85);
      backdrop-filter: blur(12px);
      box-shadow: 0 1px 4px rgba(0,0,0,0.04);
      z-index: 100;
      display: flex;
      align-items: center;
    }

    .nav-container {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
    }

    .logo {
      font-size: 1.7rem;
      font-weight: 700;
      color: var(--deep-blue);
      letter-spacing: -0.5px;
      display: flex;
      align-items: center;
      gap: 8px;
    }
    .logo i {
      color: var(--gold);
      font-size: 2rem;
    }

    .nav-links {
      display: flex;
      gap: 32px;
      align-items: center;
    }

    .nav-links a {
      font-weight: 500;
      color: var(--text-primary);
      font-size: 1rem;
      position: relative;
      padding: 8px 0;
    }

    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--gold);
      transition: width 0.3s;
    }

    .nav-links a:hover::after,
    .nav-links a.active::after {
      width: 100%;
    }

    .menu-toggle {
      display: none;
      font-size: 1.8rem;
      color: var(--deep-blue);
    }

    /* 按钮 */
    .btn-primary {
      background: var(--deep-blue);
      color: white;
      padding: 14px 32px;
      border-radius: var(--radius-button);
      font-weight: 600;
      box-shadow: 0 4px 10px rgba(10,22,40,0.2);
    }
    .btn-primary:hover {
      background: var(--gold);
      box-shadow: 0 8px 18px rgba(200,155,60,0.3);
      transform: translateY(-1px);
    }

    .btn-secondary {
      border: 2px solid var(--deep-blue);
      color: var(--deep-blue);
      padding: 12px 28px;
      border-radius: var(--radius-button);
      font-weight: 600;
      background: transparent;
    }
    .btn-secondary:hover {
      background: rgba(10,22,40,0.05);
      border-color: var(--gold);
      color: var(--gold);
    }

    /* Hero */
    .hero {
      min-height: 90vh;
      display: flex;
      align-items: center;
      justify-content: center;
      background: linear-gradient(rgba(10, 22, 40, 0.8), rgba(10, 22, 40, 0.7)), url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      color: white;
      text-align: center;
      margin-top: var(--nav-height);
      padding: 60px 0;
    }

    .hero-content {
      max-width: 800px;
    }
    .hero h1 {
      font-size: 3.5rem;
      margin-bottom: 20px;
      text-shadow: 0 4px 12px rgba(0,0,0,0.4);
    }
    .hero .subtitle {
      font-size: 1.3rem;
      color: rgba(255,255,255,0.85);
      margin-bottom: 32px;
    }

    /* 通用区块 */
    .section {
      padding: 100px 0;
    }
    .section-title {
      text-align: center;
      margin-bottom: 60px;
    }
    .section-title h2 {
      color: var(--deep-blue);
    }
    .section-title p {
      color: var(--text-muted);
      max-width: 600px;
      margin: 0 auto;
      font-size: 1.1rem;
    }

    /* 网格卡片 */
    .grid-3 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 28px;
    }
    .card {
      background: var(--white);
      border-radius: var(--radius-card);
      padding: 32px;
      box-shadow: var(--shadow-card);
      transition: var(--transition);
      text-align: center;
    }
    .card:hover {
      box-shadow: var(--shadow-card-hover);
      transform: translateY(-2px);
    }
    .card-icon {
      font-size: 2.8rem;
      color: var(--gold);
      margin-bottom: 20px;
    }
    .card h3 {
      margin-bottom: 12px;
      color: var(--deep-blue);
    }

    /* 左右交替图文 */
    .alt-block {
      display: flex;
      align-items: center;
      gap: 60px;
      margin-bottom: 80px;
    }
    .alt-block.reverse {
      flex-direction: row-reverse;
    }
    .alt-text {
      flex: 1;
    }
    .alt-image {
      flex: 1;
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-card);
    }
    .alt-image img {
      width: 100%;
      height: auto;
      object-fit: cover;
    }

    /* 数据指标条 */
    .stats-bar {
      display: flex;
      justify-content: space-around;
      background: var(--white);
      border-radius: var(--radius-card);
      padding: 32px 24px;
      box-shadow: var(--shadow-card);
      margin-top: 40px;
    }
    .stat-item {
      text-align: center;
    }
    .stat-number {
      font-size: 2.5rem;
      font-weight: 700;
      color: var(--deep-blue);
    }
    .stat-label {
      color: var(--text-muted);
      font-size: 0.95rem;
    }

    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }
    .faq-item {
      border-bottom: 1px solid var(--border-light);
      padding: 20px 0;
    }
    .faq-question {
      display: flex;
      align-items: center;
      gap: 12px;
      font-weight: 600;
      font-size: 1.1rem;
      color: var(--deep-blue);
      cursor: pointer;
      background: none;
      border: none;
      width: 100%;
      text-align: left;
      padding: 8px 0;
    }
    .faq-question i {
      color: var(--gold);
      font-size: 1.3rem;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease;
      padding-left: 28px;
      color: var(--text-secondary);
      margin-top: 0;
    }
    .faq-item.open .faq-answer {
      max-height: 200px;
      margin-top: 12px;
    }

    /* CTA */
    .cta-section {
      background: var(--deep-blue);
      color: white;
      text-align: center;
      padding: 80px 0;
      border-radius: 24px 24px 0 0;
    }
    .cta-section h2 {
      color: white;
    }

    /* 页脚 */
    .footer {
      background: #091320;
      color: #9CA3AF;
      padding: 60px 0 30px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
    }
    .footer h4 {
      color: white;
      margin-bottom: 16px;
      font-weight: 600;
    }
    .footer a {
      color: #9CA3AF;
      display: block;
      margin-bottom: 8px;
    }
    .footer a:hover {
      color: var(--gold);
    }
    .copyright {
      border-top: 1px solid #2D3748;
      margin-top: 40px;
      padding-top: 24px;
      text-align: center;
      font-size: 0.9rem;
    }

    @media (max-width: 1024px) {
      .grid-3 { grid-template-columns: repeat(2, 1fr); }
    }
    @media (max-width: 768px) {
      .container { padding: 0 20px; }
      h1 { font-size: 2.4rem; }
      h2 { font-size: 2rem; }
      .nav-links { display: none; }
      .menu-toggle { display: block; }
      .hero { min-height: 70vh; }
      .grid-3 { grid-template-columns: 1fr; }
      .alt-block, .alt-block.reverse { flex-direction: column; }
      .footer-grid { grid-template-columns: 1fr 1fr; }
      .section { padding: 60px 0; }
    }