/* roulang page: index */
/* === 设计变量与全局重置 === */
    :root {
      --primary: #7B2FF7;
      --primary-dark: #6828D4;
      --secondary: #00F0FF;
      --bg-dark: #0B0C10;
      --bg-card: #1F1F24;
      --text-white: #FFFFFF;
      --text-light: #B0B3C1;
      --text-muted: #8A8D9C;
      --border-dim: rgba(255, 255, 255, 0.08);
      --radius-card: 12px;
      --radius-btn: 50px;
      --shadow-purple: 0 8px 24px rgba(123, 47, 247, 0.25);
      --shadow-cyan: 0 0 16px rgba(0, 240, 255, 0.25);
      --section-gap: 120px;
      --mobile-gap: 80px;
    }
    
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }
    
    body {
      background-color: var(--bg-dark);
      color: var(--text-light);
      font-family: 'Inter', 'PingFang SC', 'Microsoft YaHei', sans-serif;
      line-height: 1.8;
      letter-spacing: 0.5px;
      -webkit-font-smoothing: antialiased;
      overflow-x: hidden;
    }
    
    h1, h2, h3, h4, h5, h6 {
      font-weight: 700;
      color: var(--text-white);
      line-height: 1.2;
    }
    
    h1 { font-size: 3.5rem; font-weight: 800; }
    h2 { font-size: 2.25rem; font-weight: 700; }
    h3 { font-size: 1.5rem; font-weight: 600; }
    
    p {
      color: var(--text-light);
      margin-bottom: 1.5rem;
    }
    
    a {
      text-decoration: none;
      color: inherit;
      transition: color 0.25s ease;
    }
    
    img {
      max-width: 100%;
      display: block;
    }
    
    button, .btn {
      cursor: pointer;
      font-family: inherit;
      transition: all 0.3s ease;
      border: none;
      outline: none;
      font-weight: 600;
      letter-spacing: 0.3px;
    }
    
    .container {
      max-width: 1280px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 24px;
      padding-right: 24px;
      width: 100%;
    }
    
    /* 导航与毛玻璃背景 */
    .navbar {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 50;
      background: rgba(11, 12, 16, 0.7);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
      border-bottom: 1px solid var(--border-dim);
      transition: background 0.3s, box-shadow 0.3s;
    }
    .navbar.scrolled {
      background: rgba(11, 12, 16, 0.92);
      box-shadow: 0 8px 20px rgba(0,0,0,0.5);
    }
    
    .nav-link {
      color: var(--text-light);
      padding: 0.5rem 1rem;
      font-weight: 500;
      position: relative;
      transition: color 0.2s;
    }
    .nav-link::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 50%;
      transform: translateX(-50%);
      width: 0;
      height: 2px;
      background: var(--secondary);
      transition: width 0.25s ease;
    }
    .nav-link:hover {
      color: var(--text-white);
    }
    .nav-link:hover::after {
      width: 60%;
    }
    
    /* Hero 动态背景粒子风格 */
    .hero-bg-overlay {
      position: absolute;
      inset: 0;
      background: radial-gradient(circle at 30% 40%, rgba(123,47,247,0.18) 0%, transparent 70%),
                  linear-gradient(135deg, #0B0C10 30%, #1a1530 100%);
      background-size: cover;
    }
    .particle-dot {
      position: absolute;
      background: rgba(123,47,247,0.4);
      width: 6px;
      height: 6px;
      border-radius: 50%;
      box-shadow: 0 0 10px #7B2FF7;
    }
    
    /* 卡片组件 */
    .feature-card {
      background: var(--bg-card);
      border-radius: var(--radius-card);
      padding: 1.5rem;
      transition: transform 0.25s, box-shadow 0.35s;
      border: 1px solid var(--border-dim);
    }
    .feature-card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-purple);
    }
    .feature-icon {
      font-size: 2rem;
      color: var(--secondary);
      margin-bottom: 0.75rem;
      display: inline-block;
      transition: transform 0.3s;
    }
    .feature-card:hover .feature-icon {
      transform: rotate(5deg);
      color: var(--secondary);
    }
    
    .case-card {
      background: #1a1a20;
      border-radius: var(--radius-card);
      overflow: hidden;
      transition: 0.3s;
      box-shadow: 0 4px 12px rgba(0,0,0,0.4);
    }
    .case-card:hover {
      transform: translateY(-5px);
      box-shadow: var(--shadow-purple);
    }
    .badge-mvp {
      background: var(--primary);
      color: white;
      font-size: 0.75rem;
      padding: 0.15rem 0.8rem;
      border-radius: 20px;
      font-weight: 600;
    }
    
    .plan-card {
      background: var(--bg-card);
      border-radius: 16px;
      padding: 2rem 1.5rem;
      border: 1px solid var(--border-dim);
      transition: all 0.3s;
    }
    .plan-card.featured {
      border-color: var(--primary);
      box-shadow: var(--shadow-purple);
      transform: scale(1.02);
    }
    .price-cyan {
      color: var(--secondary);
      font-weight: 800;
    }
    
    .faq-item {
      border-bottom: 1px solid var(--border-dim);
    }
    .faq-question {
      cursor: pointer;
      padding: 1.2rem 0;
      font-weight: 600;
      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 0.2s;
      color: var(--text-light);
      font-size: 1rem;
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      padding-bottom: 1rem;
    }
    
    .btn-primary {
      background: var(--primary);
      color: white;
      border-radius: var(--radius-btn);
      padding: 0.75rem 2rem;
      box-shadow: 0 4px 12px rgba(123,47,247,0.6);
    }
    .btn-primary:hover {
      background: var(--secondary);
      color: #0B0C10;
      box-shadow: var(--shadow-cyan);
      transform: translateY(-2px);
    }
    .btn-outline {
      background: transparent;
      border: 2px solid var(--secondary);
      color: var(--secondary);
      border-radius: var(--radius-btn);
      padding: 0.7rem 2rem;
    }
    .btn-outline:hover {
      background: var(--secondary);
      color: #0B0C10;
    }
    
    .pulse-animation {
      animation: pulse-glow 2.4s infinite;
    }
    @keyframes pulse-glow {
      0% { box-shadow: 0 0 0 0 rgba(123,47,247,0.7); }
      70% { box-shadow: 0 0 0 12px rgba(123,47,247,0); }
      100% { box-shadow: 0 0 0 0 rgba(123,47,247,0); }
    }
    
    /* 移动端汉堡菜单 */
    @media (max-width: 768px) {
      h1 { font-size: 2.6rem; }
      h2 { font-size: 1.9rem; }
      .mobile-menu {
        position: fixed;
        top: 0;
        right: -100%;
        width: 75%;
        max-width: 300px;
        height: 100vh;
        background: #0f0f14;
        backdrop-filter: blur(20px);
        flex-direction: column;
        padding: 5rem 2rem;
        transition: right 0.4s ease;
        z-index: 60;
      }
      .mobile-menu.open {
        right: 0;
      }
      .plan-card.featured {
        transform: none;
      }
    }