/* roulang page: index */
/* :root 设计变量 */
    :root {
      --primary-deep: #0B1C3A;
      --primary-bg: #0F2442;
      --primary-card: #132B4F;
      --accent-gold: #F0B34B;
      --accent-gold-dark: #E89F2E;
      --text-light: #E8EDF5;
      --text-muted: #A0B3D0;
      --border-glass: rgba(255, 255, 255, 0.1);
      --border-glow: rgba(240, 179, 75, 0.3);
      --radius-card: 16px;
      --radius-btn: 8px;
      --radius-input: 8px;
      --shadow-card: 0 8px 32px rgba(0, 0, 0, 0.4);
      --shadow-glow: 0 0 18px rgba(240, 179, 75, 0.6);
      --font-sans: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", sans-serif;
      --transition-smooth: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    }

    /* reset/base */
    *, *::before, *::after {
      box-sizing: border-box;
    }
    body {
      font-family: var(--font-sans);
      background: linear-gradient(170deg, #0B1C3A 0%, #0F2442 100%);
      color: var(--text-light);
      margin: 0;
      line-height: 1.7;
      -webkit-font-smoothing: antialiased;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    a {
      color: inherit;
      text-decoration: none;
    }
    button, input, textarea {
      font-family: inherit;
      outline: none;
    }

    /* 容器 */
    .container {
      max-width: 1280px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 20px;
      padding-right: 20px;
    }

    /* 导航栏 - 桌面顶部固定 */
    .navbar {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 72px;
      background: rgba(11, 28, 58, 0.8);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
      border-bottom: 1px solid rgba(255, 255, 255, 0.08);
      z-index: 50;
      display: flex;
      align-items: center;
    }
    .nav-container {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
    }
    .logo {
      display: flex;
      align-items: center;
      gap: 8px;
      font-size: 1.5rem;
      font-weight: 700;
      color: #fff;
      letter-spacing: 0.5px;
    }
    .logo i {
      color: var(--accent-gold);
      font-size: 1.8rem;
    }
    .nav-links {
      display: flex;
      gap: 32px;
      align-items: center;
      list-style: none;
      margin: 0;
      padding: 0;
    }
    .nav-links li a {
      font-size: 0.95rem;
      font-weight: 500;
      color: var(--text-muted);
      padding-bottom: 4px;
      border-bottom: 2px solid transparent;
      transition: color var(--transition-smooth), border-color var(--transition-smooth);
    }
    .nav-links li a:hover,
    .nav-links li a.active {
      color: #fff;
      border-bottom-color: var(--accent-gold);
    }

    /* 移动端底部Tab栏 */
    .mobile-tab-bar {
      display: none;
      position: fixed;
      bottom: 0;
      left: 0;
      width: 100%;
      height: 64px;
      background: rgba(11, 28, 58, 0.95);
      backdrop-filter: blur(20px);
      -webkit-backdrop-filter: blur(20px);
      border-top: 1px solid rgba(255, 255, 255, 0.1);
      z-index: 50;
      justify-content: space-around;
      align-items: center;
    }
    .tab-item {
      display: flex;
      flex-direction: column;
      align-items: center;
      color: var(--text-muted);
      font-size: 0.7rem;
      gap: 2px;
      transition: color 0.2s;
    }
    .tab-item i {
      font-size: 1.4rem;
    }
    .tab-item.active {
      color: var(--accent-gold);
      text-shadow: 0 0 8px rgba(240,179,75,0.5);
    }

    /* 板块通用 */
    section {
      padding: 100px 0;
    }
    .section-title {
      font-size: 2.2rem;
      font-weight: 700;
      margin-bottom: 16px;
      color: #fff;
    }
    .section-subtitle {
      color: var(--text-muted);
      max-width: 700px;
      margin-bottom: 48px;
    }

    /* 玻璃拟态卡片 */
    .glass-card {
      background: rgba(255, 255, 255, 0.04);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
      border: 1px solid var(--border-glass);
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-card);
      padding: 24px;
      transition: transform var(--transition-smooth), border-color 0.3s;
    }
    .glass-card:hover {
      border-color: var(--border-glow);
      transform: translateY(-4px);
    }

    /* 按钮体系 */
    .btn-primary {
      background: linear-gradient(135deg, var(--accent-gold) 0%, var(--accent-gold-dark) 100%);
      color: #0a1a2f;
      font-weight: 700;
      padding: 14px 36px;
      border-radius: var(--radius-btn);
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      border: none;
      cursor: pointer;
      transition: all var(--transition-smooth);
      box-shadow: 0 4px 12px rgba(0,0,0,0.3);
      letter-spacing: 0.8px;
    }
    .btn-primary:hover {
      box-shadow: var(--shadow-glow);
      transform: scale(1.03);
      color: #0a1a2f;
    }
    .btn-outline {
      background: transparent;
      border: 1px solid rgba(255,255,255,0.5);
      color: #fff;
      font-weight: 600;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      display: inline-flex;
      align-items: center;
      gap: 8px;
      transition: all var(--transition-smooth);
    }
    .btn-outline:hover {
      border-color: var(--accent-gold);
      box-shadow: 0 0 12px rgba(240,179,75,0.4);
      color: var(--accent-gold);
    }

    /* Hero 指标卡片 */
    .metric-card {
      background: rgba(255,255,255,0.05);
      backdrop-filter: blur(8px);
      border: 1px solid rgba(255,255,255,0.12);
      border-radius: 12px;
      padding: 16px 18px;
      text-align: center;
    }
    .metric-number {
      font-size: 2.4rem;
      font-weight: 800;
      color: var(--accent-gold);
      line-height: 1.2;
    }

    /* 输入框 */
    .input-field {
      width: 100%;
      background: rgba(0,0,0,0.3);
      border: 1px solid rgba(255,255,255,0.2);
      border-radius: var(--radius-input);
      padding: 14px 16px;
      color: #fff;
      transition: border-color 0.3s;
    }
    .input-field:focus {
      border-color: var(--accent-gold);
      box-shadow: 0 0 8px rgba(240,179,75,0.3);
    }

    /* FAQ 手风琴 */
    .faq-item {
      border-bottom: 1px solid rgba(255,255,255,0.08);
      cursor: pointer;
    }
    .faq-question {
      font-size: 1.1rem;
      font-weight: 600;
      padding: 20px 0;
      display: flex;
      justify-content: space-between;
      align-items: center;
      color: #fff;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease, padding 0.4s;
      color: var(--text-muted);
      line-height: 1.7;
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      padding-bottom: 20px;
    }
    .faq-item.active .faq-question {
      color: var(--accent-gold);
    }

    /* 页脚 */
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr;
      gap: 40px;
    }

    /* 响应式断点 */
    @media (max-width: 1024px) {
      .nav-links { gap: 20px; }
    }
    @media (max-width: 768px) {
      .navbar { display: none; }
      .mobile-tab-bar { display: flex; }
      section { padding: 70px 0; }
      .footer-grid { grid-template-columns: 1fr; }
      .hero-container { flex-direction: column; }
    }
    @media (max-width: 640px) {
      .section-title { font-size: 1.8rem; }
      .metric-grid { grid-template-columns: repeat(2,1fr); }
    }