/* roulang page: index */
/* 设计变量与基础重置 */
    :root {
      --deep-space: #0A0E27;
      --electric-purple: #7B2FFF;
      --cyan: #00E5FF;
      --neon-pink: #FF2D78;
      --text-primary: rgba(255,255,255,0.92);
      --text-secondary: rgba(255,255,255,0.65);
      --border-subtle: rgba(255,255,255,0.08);
      --border-glow: rgba(0,229,355,0.4);
      --glass-bg: rgba(255,255,255,0.03);
      --shadow-card: 0 8px 32px rgba(0,0,0,0.5);
      --radius-lg: 20px;
      --radius-pill: 50px;
      --space-section: 100px;
      --container-max: 1280px;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    html {
      scroll-behavior: smooth;
      background-color: var(--deep-space);
    }
    body {
      font-family: 'Inter', 'PingFang SC', 'Microsoft YaHei', system-ui, -apple-system, sans-serif;
      background: var(--deep-space);
      color: var(--text-primary);
      line-height: 1.8;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
      overflow-x: hidden;
    }
    img {
      max-width: 100%;
      display: block;
    }
    a {
      color: inherit;
      text-decoration: none;
    }
    button, .btn {
      cursor: pointer;
      font-family: inherit;
      border: none;
      background: none;
    }
    .container {
      max-width: var(--container-max);
      margin: 0 auto;
      padding: 0 24px;
      width: 100%;
    }
    /* 背景星云纹理 */
    .bg-starry {
      background-image: radial-gradient(circle at 30% 40%, rgba(123,47,255,0.08) 0%, transparent 45%), 
                        radial-gradient(circle at 80% 20%, rgba(0,229,255,0.06) 0%, transparent 50%);
    }
    section {
      padding: var(--space-section) 0;
      position: relative;
    }
    .section-title {
      font-size: 42px;
      font-weight: 700;
      letter-spacing: 1px;
      margin-bottom: 16px;
      color: white;
      text-shadow: 0 0 15px rgba(0,229,255,0.3);
    }
    .section-subtitle {
      color: var(--text-secondary);
      font-size: 18px;
      margin-bottom: 48px;
    }
    /* 导航 */
    .navbar {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 72px;
      background: rgba(10,14,39,0.75);
      backdrop-filter: blur(20px);
      -webkit-backdrop-filter: blur(20px);
      border-bottom: 1px solid rgba(0,229,255,0.2);
      z-index: 1000;
      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: 10px;
      font-size: 24px;
      font-weight: 700;
      color: white;
      letter-spacing: 2px;
    }
    .logo-icon {
      width: 28px;
      height: 28px;
      border: 2px solid var(--cyan);
      border-radius: 50%;
      box-shadow: 0 0 12px var(--cyan);
      background: radial-gradient(circle at 30% 30%, rgba(0,229,255,0.5), transparent);
    }
    .nav-links {
      display: flex;
      gap: 40px;
      align-items: center;
      font-size: 15px;
      color: var(--text-secondary);
    }
    .nav-links a {
      transition: all 0.2s ease;
      font-weight: 500;
    }
    .nav-links a:hover {
      color: white;
      text-shadow: 0 0 12px var(--cyan);
    }
    .menu-toggle {
      display: none;
      flex-direction: column;
      gap: 6px;
      background: transparent;
      border: none;
      padding: 10px;
    }
    .menu-toggle span {
      display: block;
      width: 24px;
      height: 2px;
      background: white;
      transition: 0.3s;
      box-shadow: 0 0 6px var(--cyan);
    }
    /* 移动端抽屉 */
    .mobile-drawer {
      position: fixed;
      top: 0;
      right: 0;
      width: 75%;
      max-width: 320px;
      height: 100vh;
      background: rgba(8,12,32,0.96);
      backdrop-filter: blur(30px);
      display: flex;
      flex-direction: column;
      justify-content: center;
      align-items: center;
      gap: 40px;
      transform: translateX(100%);
      transition: transform 0.3s ease;
      z-index: 1200;
      font-size: 20px;
    }
    .mobile-drawer.open {
      transform: translateX(0);
    }
    .drawer-close {
      position: absolute;
      top: 30px;
      right: 30px;
      font-size: 28px;
      color: white;
      background: none;
      border: none;
    }
    /* 按钮样式 */
    .btn-primary {
      background: linear-gradient(135deg, var(--electric-purple), var(--cyan));
      color: white;
      font-weight: 700;
      padding: 14px 38px;
      border-radius: var(--radius-pill);
      box-shadow: 0 4px 24px rgba(123,47,255,0.5);
      transition: all 0.25s ease;
      display: inline-block;
      text-align: center;
    }
    .btn-primary:hover {
      filter: brightness(1.25);
      transform: scale(1.05);
      box-shadow: 0 0 30px var(--cyan);
    }
    .btn-outline {
      background: transparent;
      border: 1px solid var(--cyan);
      color: var(--cyan);
      padding: 14px 38px;
      border-radius: var(--radius-pill);
      font-weight: 600;
      transition: 0.25s;
      box-shadow: 0 0 12px rgba(0,229,255,0.15);
    }
    .btn-outline:hover {
      background: rgba(0,229,255,0.1);
      color: white;
      box-shadow: 0 0 22px var(--cyan);
    }
    .btn-large {
      padding: 18px 48px;
      font-size: 18px;
      letter-spacing: 2px;
    }
    /* 区块设计 */
    .hero {
      height: 100vh;
      display: flex;
      align-items: center;
      justify-content: center;
      position: relative;
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
    }
    .hero-overlay {
      background: rgba(10,14,39,0.65);
      backdrop-filter: blur(6px);
      width: 100%;
      height: 100%;
      display: flex;
      align-items: center;
    }
    .hero-content {
      text-align: center;
      max-width: 860px;
      margin: 0 auto;
    }
    .hero h1 {
      font-size: 56px;
      font-weight: 800;
      margin-bottom: 24px;
      text-shadow: 0 0 35px var(--electric-purple);
      color: white;
    }
    .scroll-indicator {
      margin-top: 48px;
      font-size: 24px;
      animation: bounce 2s infinite;
      color: var(--cyan);
    }
    @keyframes bounce {
      0%,100%{ transform: translateY(0); }
      50%{ transform: translateY(8px); }
    }
    .card-grid {
      display: grid;
      grid-template-columns: repeat(3,1fr);
      gap: 30px;
      margin-top: 30px;
    }
    .glass-card {
      background: var(--glass-bg);
      backdrop-filter: blur(20px);
      border: 1px solid var(--border-subtle);
      border-radius: var(--radius-lg);
      padding: 32px 24px;
      box-shadow: var(--shadow-card);
      transition: all 0.3s ease;
      position: relative;
    }
    .glass-card:hover {
      transform: translateY(-10px);
      border-color: var(--border-glow);
      box-shadow: 0 18px 40px rgba(0,229,255,0.25);
    }
    .card-icon {
      width: 60px;
      height: 60px;
      background: rgba(0,229,255,0.08);
      border-radius: 16px;
      display: flex;
      align-items: center;
      justify-content: center;
      margin-bottom: 24px;
      color: var(--cyan);
      font-size: 28px;
    }
    .decor-line {
      height: 2px;
      background: linear-gradient(90deg, var(--electric-purple), var(--cyan));
      width: 60px;
      margin-top: 24px;
    }
    /* 数据优势数字 */
    .stat-number {
      font-size: 48px;
      font-weight: 800;
      color: white;
      text-shadow: 0 0 28px var(--cyan);
    }
    /* FAQ手风琴 */
    .faq-item {
      border-bottom: 1px solid rgba(255,255,255,0.08);
      padding: 20px 10px;
      cursor: pointer;
      transition: background 0.2s;
    }
    .faq-question {
      display: flex;
      justify-content: space-between;
      font-weight: 600;
      font-size: 18px;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease, background 0.3s;
      color: var(--text-secondary);
      margin-top: 8px;
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      background: rgba(255,255,255,0.02);
      padding: 12px;
      border-radius: 12px;
    }
    footer {
      background: #060B1C;
      padding-top: 80px;
      padding-bottom: 30px;
      border-top: 1px solid rgba(255,255,255,0.06);
    }
    @media (max-width: 1024px) {
      .card-grid { grid-template-columns: repeat(2,1fr); }
    }
    @media (max-width: 768px) {
      .nav-links { display: none; }
      .menu-toggle { display: flex; }
      .hero h1 { font-size: 36px; }
      .section-title { font-size: 28px; }
      .card-grid { grid-template-columns: 1fr; }
      .btn-primary, .btn-outline { width: 100%; text-align: center; }
    }
    @media (max-width: 520px) {
      footer .grid-4 { grid-template-columns: 1fr; }
    }