/* roulang page: index */
/* 全局设计变量与基础重置 */
    :root {
      --bg-deep: #0B0C10;
      --bg-darker: #06070A;
      --purple-electric: #A239EA;
      --purple-deep: #7B2D8E;
      --cyan-neon: #00F0FF;
      --gray-blue: #1F2833;
      --white-pure: #FFFFFF;
      --white-soft: rgba(255, 255, 255, 0.7);
      --white-muted: rgba(255, 255, 255, 0.5);
      --glass-bg: rgba(31, 40, 51, 0.45);
      --glass-border: rgba(255, 255, 255, 0.08);
      --card-shadow: 0 8px 32px rgba(0, 0, 0, 0.5);
      --glow-purple: 0 0 18px rgba(162, 57, 234, 0.7);
      --glow-cyan: 0 0 14px rgba(0, 240, 255, 0.6);
      --radius-lg: 20px;
      --radius-md: 14px;
      --radius-sm: 8px;
      --radius-pill: 30px;
      --font-sans: 'Inter', 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', sans-serif;
      --transition-fast: 0.2s ease;
      --transition-smooth: 0.3s cubic-bezier(0.23, 1, 0.32, 1);
      --container-max: 1200px;
      --section-gap: 90px;
      --card-gap: 24px;
    }

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

    html {
      scroll-behavior: smooth;
      font-size: 16px;
    }

    body {
      font-family: var(--font-sans);
      background-color: var(--bg-deep);
      color: var(--white-soft);
      line-height: 1.5;
      -webkit-font-smoothing: antialiased;
      background-image: 
        linear-gradient(rgba(162, 57, 234, 0.02) 1px, transparent 1px),
        linear-gradient(90deg, rgba(162, 57, 234, 0.02) 1px, transparent 1px);
      background-size: 40px 40px;
      overflow-x: hidden;
    }

    .container {
      max-width: var(--container-max);
      margin: 0 auto;
      padding: 0 24px;
    }

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

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

    button, input, select, textarea {
      font-family: inherit;
      outline: none;
      border: none;
    }

    /* 玻璃拟态卡片规范 */
    .glass-card {
      background: var(--glass-bg);
      backdrop-filter: blur(14px);
      -webkit-backdrop-filter: blur(14px);
      border: 1px solid var(--glass-border);
      border-radius: var(--radius-lg);
      box-shadow: var(--card-shadow);
      transition: transform var(--transition-smooth), box-shadow var(--transition-smooth), border-color var(--transition-smooth);
    }

    .glass-card:hover {
      transform: translateY(-6px);
      border-color: rgba(162, 57, 234, 0.5);
      box-shadow: 0 14px 36px rgba(0, 0, 0, 0.6), 0 0 20px rgba(162, 57, 234, 0.45);
    }

    /* 按钮系统 */
    .btn-primary {
      background: linear-gradient(135deg, var(--purple-electric) 0%, var(--purple-deep) 100%);
      color: var(--white-pure);
      font-weight: 600;
      border-radius: var(--radius-pill);
      padding: 14px 32px;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      box-shadow: var(--glow-purple);
      transition: all var(--transition-smooth);
      border: none;
      cursor: pointer;
      letter-spacing: 0.3px;
    }

    .btn-primary:hover {
      box-shadow: 0 0 28px rgba(162, 57, 234, 0.9);
      transform: scale(1.04);
      filter: brightness(1.1);
    }

    .btn-outline {
      background: transparent;
      border: 2px solid var(--cyan-neon);
      color: var(--cyan-neon);
      font-weight: 600;
      border-radius: var(--radius-pill);
      padding: 14px 32px;
      backdrop-filter: blur(6px);
      transition: all var(--transition-smooth);
      cursor: pointer;
    }

    .btn-outline:hover {
      background: rgba(0, 240, 255, 0.08);
      box-shadow: var(--glow-cyan);
      transform: scale(1.04);
    }

    /* 导航栏 */
    .site-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 100;
      background: rgba(11, 12, 16, 0.8);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
      border-bottom: 1px solid rgba(0, 240, 255, 0.25);
      height: 72px;
      display: flex;
      align-items: center;
    }

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

    .logo {
      font-size: 1.7rem;
      font-weight: 800;
      background: linear-gradient(to right, var(--purple-electric), var(--cyan-neon));
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
      letter-spacing: -0.5px;
    }

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

    .nav-link {
      font-weight: 500;
      color: var(--white-soft);
      position: relative;
      padding: 8px 0;
      transition: color var(--transition-fast);
    }

    .nav-link:hover,
    .nav-link.active {
      color: var(--cyan-neon);
    }

    .nav-link.active::after {
      content: '';
      position: absolute;
      bottom: -4px;
      left: 0;
      width: 100%;
      height: 2px;
      background: var(--cyan-neon);
      box-shadow: 0 0 10px var(--cyan-neon);
    }

    .menu-toggle {
      display: none;
      background: transparent;
      color: var(--white-pure);
      font-size: 1.8rem;
      cursor: pointer;
    }

    /* 移动端底部导航 */
    .mobile-bottom-nav {
      display: none;
      position: fixed;
      bottom: 0;
      left: 0;
      width: 100%;
      background: rgba(6, 7, 10, 0.95);
      backdrop-filter: blur(20px);
      border-top: 1px solid rgba(162, 57, 234, 0.4);
      height: 64px;
      z-index: 99;
      justify-content: space-around;
      align-items: center;
    }

    .bottom-tab {
      display: flex;
      flex-direction: column;
      align-items: center;
      color: var(--white-muted);
      font-size: 0.7rem;
      transition: color var(--transition-fast);
      gap: 4px;
    }

    .bottom-tab i {
      font-size: 1.4rem;
    }

    .bottom-tab.active {
      color: var(--purple-electric);
      text-shadow: 0 0 8px var(--purple-electric);
    }

    /* Hero 粒子背景 */
    .hero-section {
      min-height: 100vh;
      display: flex;
      align-items: center;
      justify-content: center;
      position: relative;
      background: radial-gradient(circle at 30% 40%, rgba(162, 57, 234, 0.15) 0%, transparent 50%);
      overflow: hidden;
    }

    #particle-canvas {
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      pointer-events: none;
    }

    .hero-content {
      position: relative;
      z-index: 2;
      text-align: center;
      max-width: 850px;
      padding: 0 20px;
    }

    h1 {
      font-size: clamp(2.8rem, 8vw, 4rem);
      font-weight: 800;
      line-height: 1.2;
      background: linear-gradient(to right, #C084FC, var(--purple-electric), var(--cyan-neon));
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
      margin-bottom: 1.2rem;
    }

    h2 {
      font-size: 2.2rem;
      font-weight: 700;
      color: var(--white-pure);
      margin-bottom: 0.8rem;
    }

    .section-subtitle {
      color: var(--white-soft);
      font-size: 1.1rem;
      max-width: 650px;
      margin: 0 auto;
    }

    .scroll-indicator {
      position: absolute;
      bottom: 30px;
      left: 50%;
      transform: translateX(-50%);
      color: var(--cyan-neon);
      font-size: 2rem;
      animation: bounce 2s infinite;
    }

    @keyframes bounce {
      0%, 20%, 50%, 80%, 100% { transform: translateX(-50%) translateY(0); }
      40% { transform: translateX(-50%) translateY(-12px); }
      60% { transform: translateX(-50%) translateY(-5px); }
    }

    section {
      padding: var(--section-gap) 0;
    }

    .grid-3 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: var(--card-gap);
    }

    .grid-4 {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: var(--card-gap);
    }

    .feature-icon {
      font-size: 2.2rem;
      color: var(--cyan-neon);
      margin-bottom: 1.2rem;
    }

    .data-number {
      font-size: 2.8rem;
      font-weight: 800;
      color: var(--cyan-neon);
      text-shadow: 0 0 12px var(--cyan-neon);
    }

    .faq-item {
      border-bottom: 1px solid rgba(255,255,255,0.1);
      padding: 18px 0;
      cursor: pointer;
    }

    .faq-question {
      display: flex;
      justify-content: space-between;
      font-weight: 600;
      color: var(--white-pure);
    }

    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease;
      color: var(--white-soft);
      margin-top: 0;
    }

    .faq-item.active .faq-answer {
      max-height: 200px;
      margin-top: 14px;
    }

    footer {
      background: var(--bg-darker);
      padding: 60px 0 30px;
    }

    @media (max-width: 1024px) {
      .grid-4 { grid-template-columns: repeat(2, 1fr); }
      .grid-3 { grid-template-columns: 1fr; }
    }

    @media (max-width: 768px) {
      .desktop-nav { display: none; }
      .menu-toggle { display: block; }
      .mobile-bottom-nav { display: flex; }
      .site-header { height: 64px; }
      .grid-4, .grid-3 { grid-template-columns: 1fr; }
      section { padding: 60px 0; }
      .hero-content h1 { font-size: 2.4rem; }
    }