/* roulang page: index */
/* 设计变量与重置 */
    :root {
      --primary-purple: #6C3CF0;
      --accent-cyan: #00F0C8;
      --bg-dark: #0A0E17;
      --bg-card: #1A1F2B;
      --gold: #FFB800;
      --text-white: #F0F2F5;
      --text-gray: #B0B8C5;
      --border-glow: rgba(108, 60, 240, 0.25);
      --shadow-card: 0 8px 24px rgba(108, 60, 240, 0.08);
      --shadow-hover: 0 14px 40px rgba(0, 240, 200, 0.25);
      --radius-card: 14px;
      --radius-btn: 40px;
      --transition: 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94);
    }
    * { box-sizing: border-box; }
    body {
      margin: 0;
      font-family: 'PingFang SC', 'Microsoft YaHei', 'Segoe UI', system-ui, -apple-system, sans-serif;
      background-color: var(--bg-dark);
      color: var(--text-gray);
      line-height: 1.75;
      font-size: 16px;
      overflow-x: hidden;
    }
    h1, h2, h3, h4, .h-title {
      font-weight: 700;
      color: var(--text-white);
      letter-spacing: 0.5px;
    }
    h1 { font-size: 48px; font-weight: 900; line-height: 1.2; }
    h2 { font-size: 36px; font-weight: 800; line-height: 1.3; margin-bottom: 1.25rem; }
    h3 { font-size: 22px; font-weight: 700; line-height: 1.4; }
    a { color: var(--accent-cyan); text-decoration: none; transition: var(--transition); }
    a:hover { color: #33F5D8; }
    img { max-width: 100%; height: auto; display: block; }
    .container { max-width: 1200px; margin: 0 auto; padding: 0 40px; }
    section { padding: 90px 0; position: relative; }
    /* 网格纹理背景点缀 */
    .bg-grid {
      background-image: repeating-linear-gradient(0deg, rgba(108,60,240,0.03) 0px, rgba(108,60,240,0.03) 1px, transparent 1px, transparent 40px),
                        repeating-linear-gradient(90deg, rgba(108,60,240,0.03) 0px, rgba(108,60,240,0.03) 1px, transparent 1px, transparent 40px);
    }
    /* 导航 */
    .top-nav {
      position: fixed; top: 0; left: 0; width: 100%; height: 70px;
      background: rgba(10, 14, 23, 0.85); backdrop-filter: blur(14px);
      border-bottom: 1px solid rgba(108, 60, 240, 0.25); z-index: 99;
      display: flex; align-items: center; padding: 0 30px;
    }
    .logo {
      font-size: 26px; font-weight: 900; background: linear-gradient(135deg, #6C3CF0, #00F0C8);
      -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text;
      letter-spacing: 1px; margin-right: auto;
    }
    .desktop-nav { display: flex; align-items: center; gap: 32px; }
    .desktop-nav a {
      color: #ccd6e0; font-weight: 600; font-size: 15px; position: relative;
    }
    .desktop-nav a:hover, .desktop-nav a.active { color: var(--accent-cyan); }
    .nav-cta {
      background: var(--accent-cyan); color: #0A0E17 !important; padding: 8px 22px;
      border-radius: 30px; font-weight: 700; margin-left: 16px; transition: var(--transition);
    }
    .nav-cta:hover { background: #33F5D8; box-shadow: 0 0 20px rgba(0,240,200,0.5); }
    .hamburger { display: none; font-size: 26px; color: white; cursor: pointer; }
    .mobile-menu { display: none; }
    /* 移动端底部Tab */
    .bottom-tabs {
      display: none; position: fixed; bottom: 0; left: 0; width: 100%; height: 64px;
      background: rgba(10,14,23,0.95); backdrop-filter: blur(20px);
      border-top: 1px solid rgba(108,60,240,0.3); z-index: 98;
      justify-content: space-around; align-items: center;
    }
    .tab-item { text-align: center; color: #8a93a0; font-size: 12px; }
    .tab-item i { font-size: 22px; display: block; margin-bottom: 2px; }
    .tab-item.active { color: var(--accent-cyan); }

    /* 按钮系统 */
    .btn-primary {
      background: var(--accent-cyan); color: #0A0E17; font-weight: 700;
      padding: 14px 36px; border-radius: var(--radius-btn); border: none;
      display: inline-block; transition: var(--transition); letter-spacing: 0.8px;
      box-shadow: 0 4px 14px rgba(0,240,200,0.25);
    }
    .btn-primary:hover { background: #33F5D8; box-shadow: 0 0 28px rgba(0,240,200,0.55); transform: scale(1.03); color:#0A0E17; }
    .btn-outline {
      background: transparent; border: 2px solid var(--accent-cyan); color: var(--accent-cyan);
      padding: 12px 34px; border-radius: var(--radius-btn); font-weight: 700;
      transition: var(--transition);
    }
    .btn-outline:hover { background: rgba(0,240,200,0.08); box-shadow: 0 0 18px rgba(0,240,200,0.3); }
    .btn-ghost {
      background: transparent; border: 1px solid rgba(255,255,255,0.5); color: white;
      padding: 10px 28px; border-radius: 30px; font-weight: 600;
    }
    .btn-ghost:hover { background: rgba(255,255,255,0.08); }

    /* 卡片 */
    .card {
      background: var(--bg-card); border-radius: var(--radius-card);
      border: 1px solid rgba(108,60,240,0.18); box-shadow: var(--shadow-card);
      transition: var(--transition); padding: 28px 22px;
    }
    .card:hover {
      border-color: var(--accent-cyan); box-shadow: var(--shadow-hover);
      transform: translateY(-6px);
    }
    .feature-card i { font-size: 44px; color: var(--accent-cyan); margin-bottom: 18px; }
    /* Hero动态粒子背景 */
    .hero-section {
      min-height: 100vh; display: flex; align-items: center; position: relative;
      background: radial-gradient(circle at 30% 40%, #1a1040 0%, #0A0E17 70%);
      overflow: hidden;
    }
    .particles { position: absolute; top:0; left:0; width:100%; height:100%; pointer-events: none; }
    /* 数字滚动 */
    .stat-number { font-size: 44px; font-weight: 800; color: var(--accent-cyan); }
    /* FAQ手风琴 */
    .accordion-item { background: var(--bg-card); border-radius: 12px; margin-bottom: 14px; border:1px solid rgba(108,60,240,0.15); }
    .accordion-title { padding: 18px 24px; font-weight: 700; color: white; cursor: pointer; display: flex; justify-content: space-between; }
    .accordion-content { padding: 0 24px 20px; display: none; color: #b0b8c5; }
    .accordion-item.active .accordion-content { display: block; }
    .accordion-item.active { border-color: var(--primary-purple); }
    /* 页脚 */
    .footer-top { border-top: 2px solid var(--primary-purple); }
    /* 响应式 */
    @media (max-width: 1024px) {
      .container { padding: 0 24px; }
      h1 { font-size: 40px; }
    }
    @media (max-width: 768px) {
      .desktop-nav { display: none; }
      .hamburger { display: block; }
      .mobile-menu.show { display: flex; flex-direction: column; position: fixed; top:70px; left:0; width:100%; height:100vh; background: rgba(10,14,23,0.98); align-items:center; justify-content:center; gap:32px; font-size:24px; z-index:97; }
      .bottom-tabs { display: flex; }
      .top-nav { padding: 0 20px; }
      .container { padding: 0 20px; }
      section { padding: 70px 0; }
      h2 { font-size: 30px; }
    }
    @media (max-width: 520px) {
      h1 { font-size: 32px; }
      .btn-primary { padding: 12px 28px; }
    }