/* roulang page: index */
:root {
      --deep-space: #0B0C10;
      --nebula-purple: #6C3FAA;
      --star-gold: #F2C94C;
      --text-white: #E8E8EF;
      --text-gray: #9A9AB0;
      --bg-card: #1A1A26;
      --bg-light-block: #16161F;
      --radius-card: 16px;
      --radius-btn: 10px;
      --radius-lg: 12px;
      --shadow-card: 0 20px 35px rgba(108, 63, 170, 0.25);
      --shadow-hover: 0 28px 45px rgba(108, 63, 170, 0.5);
      --transition-smooth: all 0.25s ease;
    }
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }
    html {
      scroll-behavior: smooth;
    }
    body {
      font-family: 'Inter', 'PingFang SC', 'Microsoft YaHei', system-ui, -apple-system, sans-serif;
      background-color: var(--deep-space);
      color: var(--text-white);
      line-height: 1.7;
      font-size: 16px;
      overflow-x: hidden;
    }
    .container-main {
      max-width: 1200px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 24px;
      padding-right: 24px;
    }
    /* 导航 */
    .header-nav {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      background: rgba(11, 12, 16, 0.9);
      backdrop-filter: blur(14px);
      z-index: 50;
      border-bottom: 1px solid rgba(242, 201, 76, 0.25);
      transition: var(--transition-smooth);
    }
    .nav-link {
      color: var(--text-gray);
      font-weight: 500;
      font-size: 0.95rem;
      position: relative;
      transition: color 0.2s;
    }
    .nav-link:hover,
    .nav-link.active {
      color: var(--star-gold);
    }
    .nav-link.active::after {
      content: '';
      position: absolute;
      bottom: -6px;
      left: 0;
      width: 100%;
      height: 2.5px;
      background: var(--star-gold);
      border-radius: 2px;
    }
    .mobile-menu {
      display: none;
    }
    @media (max-width: 768px) {
      .desktop-nav {
        display: none;
      }
      .mobile-menu {
        display: block;
      }
    }
    /* 按钮系统 */
    .btn-primary {
      background: var(--nebula-purple);
      color: white;
      border-radius: var(--radius-btn);
      padding: 14px 36px;
      font-weight: 600;
      transition: var(--transition-smooth);
      display: inline-block;
      text-align: center;
      box-shadow: 0 8px 18px rgba(108, 63, 170, 0.4);
      border: none;
      cursor: pointer;
    }
    .btn-primary:hover {
      background: #5A2F96;
      box-shadow: 0 12px 24px rgba(108, 63, 170, 0.7);
      transform: scale(1.02);
    }
    .btn-outline {
      background: transparent;
      border: 1.5px solid var(--star-gold);
      color: var(--star-gold);
      border-radius: var(--radius-btn);
      padding: 14px 36px;
      font-weight: 600;
      transition: var(--transition-smooth);
      display: inline-block;
      text-align: center;
    }
    .btn-outline:hover {
      background: rgba(242, 201, 76, 0.1);
    }
    .btn-cta-gold {
      background: var(--star-gold);
      color: var(--deep-space);
      font-weight: 700;
      border-radius: var(--radius-lg);
      padding: 16px 48px;
      transition: var(--transition-smooth);
      display: inline-block;
      text-align: center;
      box-shadow: 0 10px 28px rgba(242, 201, 76, 0.5);
    }
    .btn-cta-gold:hover {
      filter: brightness(1.15);
      transform: scale(1.03);
    }
    /* 区块间距 */
    section {
      padding: 100px 0;
    }
    @media (max-width: 768px) {
      section {
        padding: 70px 0;
      }
    }
    /* 卡片规则 */
    .card-feature {
      background: var(--bg-card);
      border-radius: var(--radius-card);
      padding: 32px 28px;
      transition: var(--transition-smooth);
      box-shadow: 0 10px 22px rgba(0,0,0,0.4);
      position: relative;
      border-left: 4px solid var(--nebula-purple);
    }
    .card-feature:hover {
      transform: translateY(-8px);
      box-shadow: var(--shadow-hover);
    }
    .feature-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 30px;
      align-items: start;
    }
    .feature-grid .card-feature:nth-child(2) {
      margin-top: -20px;
    }
    @media (max-width: 1024px) {
      .feature-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .feature-grid .card-feature:nth-child(2) {
        margin-top: 0;
      }
    }
    @media (max-width: 640px) {
      .feature-grid {
        grid-template-columns: 1fr;
      }
    }
    .product-row {
      display: flex;
      align-items: center;
      gap: 48px;
      margin-bottom: 80px;
    }
    .product-row.reverse {
      flex-direction: row-reverse;
    }
    @media (max-width: 768px) {
      .product-row, .product-row.reverse {
        flex-direction: column;
      }
    }
    /* 统计数字 */
    .stat-number {
      font-size: 2.8rem;
      font-weight: 700;
      color: var(--star-gold);
    }
    .stats-bg {
      background: radial-gradient(circle at 30% 30%, #1f1a2e, #0b0c10);
      position: relative;
      overflow: hidden;
    }
    .stats-bg::before {
      content: '';
      position: absolute;
      width: 100%;
      height: 100%;
      background-image: radial-gradient(circle, rgba(242,201,76,0.15) 1px, transparent 1px);
      background-size: 30px 30px;
      pointer-events: none;
    }
    /* FAQ */
    .faq-item {
      border-bottom: 1px solid rgba(108, 63, 170, 0.4);
      padding: 18px 0;
      cursor: pointer;
    }
    .faq-question {
      font-weight: 600;
      font-size: 1.1rem;
      display: flex;
      justify-content: space-between;
      align-items: center;
      color: var(--text-white);
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s ease, padding 0.35s ease;
      color: var(--text-gray);
    }
    .faq-answer.open {
      max-height: 200px;
      padding-top: 12px;
    }
    /* 页脚 */
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 30px;
    }
    @media (max-width: 768px) {
      .footer-grid {
        grid-template-columns: 1fr 1fr;
      }
    }
    .text-gold {
      color: var(--star-gold);
    }
    .bg-cta-gradient {
      background: radial-gradient(circle at 20% 30%, #4a2e7a, #0b0c10);
    }