/* roulang page: index */
/* ----- 设计变量 ----- */
    :root {
      --primary-deep: #0A0E27;
      --bg-deep: #060B1A;
      --card-bg: #111832;
      --accent-green: #00E5A0;
      --accent-orange: #FF6B35;
      --text-white: #FFFFFF;
      --text-light: #B0C4DE;
      --text-muted: #6B7FA3;
      --glass-bg: rgba(255, 255, 255, 0.03);
      --glass-border: rgba(255, 255, 255, 0.08);
      --glass-border-hover: rgba(255, 255, 255, 0.2);
      --radius-card: 16px;
      --radius-btn: 12px;
      --radius-input: 8px;
      --shadow-card: 0 4px 24px rgba(0, 0, 0, 0.3);
      --shadow-card-hover: 0 8px 40px rgba(0, 229, 160, 0.15);
      --glow-green: 0 0 30px rgba(0, 229, 160, 0.4);
      --glow-green-hover: 0 0 50px rgba(0, 229, 160, 0.6);
      --transition-base: all 0.25s ease;
    }
    
    /* ----- Reset & Base ----- */
    *, *::before, *::after {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }
    html {
      scroll-behavior: smooth;
    }
    body {
      font-family: 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', sans-serif;
      background-color: var(--bg-deep);
      color: var(--text-light);
      line-height: 1.6;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
      overflow-x: hidden;
    }
    a {
      text-decoration: none;
      color: inherit;
      transition: var(--transition-base);
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    button, input {
      font-family: inherit;
    }
    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
      width: 100%;
    }
    section {
      padding: 120px 0;
      position: relative;
    }
    @media (max-width: 1024px) {
      section {
        padding: 80px 0;
      }
    }
    @media (max-width: 768px) {
      section {
        padding: 60px 0;
      }
    }
    
    /* ----- 导航栏 (沉浸式半透明) ----- */
    .site-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 1000;
      background: rgba(6, 11, 26, 0.85);
      backdrop-filter: blur(24px);
      -webkit-backdrop-filter: blur(24px);
      border-bottom: 1px solid transparent;
      background-image: linear-gradient(to right, rgba(0, 229, 160, 0.2), transparent 20%, transparent 80%, rgba(0, 229, 160, 0.2));
      transition: background 0.3s;
    }
    .site-header.scrolled {
      background: rgba(6, 11, 26, 0.95);
    }
    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 72px;
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
    }
    .logo {
      display: flex;
      align-items: center;
      gap: 8px;
      font-size: 1.5rem;
      font-weight: 700;
      color: var(--text-white);
      letter-spacing: 1px;
    }
    .logo i {
      color: var(--accent-green);
      font-size: 1.8rem;
      filter: drop-shadow(0 0 8px rgba(0,229,160,0.5));
    }
    .nav-menu {
      display: flex;
      align-items: center;
      gap: 32px;
      list-style: none;
    }
    .nav-menu a {
      color: var(--text-light);
      font-weight: 500;
      font-size: 1rem;
      position: relative;
      padding: 4px 0;
    }
    .nav-menu a::after {
      content: '';
      position: absolute;
      bottom: -2px;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--accent-green);
      transition: width 0.3s;
    }
    .nav-menu a:hover::after,
    .nav-menu a.active::after {
      width: 100%;
    }
    .nav-cta {
      background: var(--accent-green);
      color: var(--primary-deep) !important;
      padding: 10px 24px;
      border-radius: 50px;
      font-weight: 700;
      box-shadow: var(--glow-green);
      transition: var(--transition-base);
      margin-left: 16px;
    }
    .nav-cta:hover {
      box-shadow: var(--glow-green-hover);
      transform: scale(1.05);
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
      background: none;
      border: none;
    }
    .hamburger span {
      width: 25px;
      height: 3px;
      background: var(--text-white);
      border-radius: 3px;
      transition: 0.3s;
    }
    
    /* 移动端底部胶囊导航 */
    .mobile-bottom-nav {
      display: none;
      position: fixed;
      bottom: 20px;
      left: 50%;
      transform: translateX(-50%);
      background: rgba(17, 24, 50, 0.9);
      backdrop-filter: blur(20px);
      border-radius: 40px;
      padding: 8px 24px;
      z-index: 999;
      box-shadow: 0 8px 30px rgba(0,0,0,0.5);
      border: 1px solid rgba(255,255,255,0.1);
    }
    .mobile-bottom-nav a {
      color: var(--text-light);
      margin: 0 12px;
      font-size: 0.9rem;
      font-weight: 500;
    }
    
    @media (max-width: 768px) {
      .nav-menu {
        display: none;
        position: fixed;
        top: 72px;
        left: 0;
        width: 100%;
        background: rgba(6, 11, 26, 0.98);
        backdrop-filter: blur(30px);
        flex-direction: column;
        padding: 32px;
        gap: 24px;
        border-bottom: 1px solid rgba(255,255,255,0.05);
      }
      .nav-menu.active {
        display: flex;
      }
      .hamburger {
        display: flex;
      }
      .nav-cta {
        margin-left: 0;
      }
      .mobile-bottom-nav {
        display: flex;
        justify-content: center;
      }
    }
    
    /* ----- Hero 首屏 ----- */
    .hero {
      padding: 160px 0 100px;
      background: radial-gradient(circle at 30% 40%, rgba(0,229,160,0.08) 0%, transparent 60%);
      position: relative;
      overflow: hidden;
    }
    .hero::before {
      content: '';
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background: repeating-linear-gradient(45deg, rgba(0,229,160,0.02) 0px, rgba(0,229,160,0.02) 2px, transparent 2px, transparent 12px);
      pointer-events: none;
    }
    .hero-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 48px;
      align-items: center;
    }
    .hero-content h1 {
      font-size: 3rem;
      font-weight: 700;
      color: var(--text-white);
      line-height: 1.3;
      margin-bottom: 24px;
    }
    .hero-content .highlight {
      color: var(--accent-green);
      text-shadow: 0 0 20px rgba(0,229,160,0.5);
    }
    .hero-sub {
      font-size: 1.125rem;
      color: var(--text-light);
      margin-bottom: 36px;
    }
    .hero-buttons {
      display: flex;
      gap: 20px;
      flex-wrap: wrap;
      margin-bottom: 20px;
    }
    .btn-primary {
      background: var(--accent-green);
      color: var(--primary-deep);
      font-weight: 700;
      padding: 16px 36px;
      border-radius: var(--radius-btn);
      box-shadow: var(--glow-green);
      border: none;
      cursor: pointer;
      transition: var(--transition-base);
      font-size: 1rem;
      display: inline-flex;
      align-items: center;
      gap: 8px;
    }
    .btn-primary:hover {
      box-shadow: var(--glow-green-hover);
      transform: scale(1.05);
      background: #00f0a8;
    }
    .btn-outline {
      background: transparent;
      border: 1px solid var(--accent-green);
      color: var(--accent-green);
      padding: 16px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      cursor: pointer;
      transition: var(--transition-base);
      display: inline-flex;
      align-items: center;
    }
    .btn-outline:hover {
      background: rgba(0,229,160,0.1);
      box-shadow: 0 0 20px rgba(0,229,160,0.2);
    }
    .hero-image {
      position: relative;
      border-radius: 24px;
      overflow: hidden;
      border: 1px solid rgba(255,255,255,0.1);
      box-shadow: 0 20px 40px rgba(0,0,0,0.5);
      background: rgba(17,24,50,0.5);
      backdrop-filter: blur(10px);
    }
    .hero-image img {
      width: 100%;
      height: auto;
      object-fit: cover;
    }
    .user-count {
      font-size: 0.9rem;
      color: var(--text-muted);
      display: flex;
      align-items: center;
      gap: 8px;
    }
    @media (max-width: 768px) {
      .hero-grid {
        grid-template-columns: 1fr;
        text-align: center;
      }
      .hero-content h1 {
        font-size: 2.2rem;
      }
    }
    
    /* 通用标题 */
    .section-title {
      font-size: 2.25rem;
      font-weight: 700;
      color: var(--text-white);
      margin-bottom: 16px;
      text-align: center;
    }
    .section-desc {
      color: var(--text-muted);
      text-align: center;
      max-width: 700px;
      margin: 0 auto 48px;
    }
    
    /* 核心优势卡片网格 */
    .features-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .feature-card {
      background: var(--glass-bg);
      backdrop-filter: blur(20px);
      border: 1px solid var(--glass-border);
      border-radius: var(--radius-card);
      padding: 32px;
      transition: var(--transition-base);
      box-shadow: var(--shadow-card);
    }
    .feature-card:hover {
      border-color: var(--glass-border-hover);
      transform: translateY(-4px);
      box-shadow: var(--shadow-card-hover);
    }
    .feature-icon {
      font-size: 2.5rem;
      color: var(--accent-green);
      margin-bottom: 20px;
    }
    .feature-card h3 {
      color: var(--text-white);
      font-size: 1.5rem;
      margin-bottom: 12px;
    }
    
    /* 功能分组 2x3 */
    .function-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .func-card {
      background: rgba(17,24,50,0.7);
      backdrop-filter: blur(16px);
      border: 1px solid rgba(255,255,255,0.05);
      border-radius: var(--radius-card);
      padding: 28px;
      transition: 0.3s;
    }
    .func-card:hover {
      border-color: var(--accent-green);
      box-shadow: 0 0 25px rgba(0,229,160,0.2);
    }
    .tag {
      display: inline-block;
      background: rgba(0,229,160,0.1);
      color: var(--accent-green);
      padding: 4px 12px;
      border-radius: 20px;
      font-size: 0.8rem;
      margin-top: 12px;
    }
    
    /* 使用场景交替布局 */
    .scene-row {
      display: flex;
      align-items: center;
      gap: 60px;
      margin-bottom: 80px;
    }
    .scene-row.reverse {
      flex-direction: row-reverse;
    }
    .scene-text {
      flex: 1;
    }
    .scene-img {
      flex: 1;
      border-radius: 16px;
      overflow: hidden;
      border: 1px solid rgba(255,255,255,0.1);
    }
    
    /* 数据卡片 */
    .stats-grid {
      display: flex;
      justify-content: space-around;
      flex-wrap: wrap;
      margin-bottom: 48px;
    }
    .stat-item {
      text-align: center;
    }
    .stat-number {
      font-size: 3rem;
      font-weight: 700;
      color: var(--accent-green);
      text-shadow: 0 0 15px rgba(0,229,160,0.4);
    }
    
    /* FAQ 手风琴 */
    .faq-item {
      border-bottom: 1px solid rgba(255,255,255,0.08);
    }
    .faq-question {
      background: none;
      border: none;
      width: 100%;
      text-align: left;
      padding: 24px 8px;
      font-size: 1.125rem;
      font-weight: 600;
      color: var(--text-white);
      display: flex;
      justify-content: space-between;
      cursor: pointer;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease;
      background: rgba(255,255,255,0.02);
      padding: 0 16px;
      color: var(--text-light);
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      padding: 16px;
    }
    
    /* CTA 区域 */
    .cta-section {
      background: radial-gradient(circle at center, rgba(0,229,160,0.15) 0%, transparent 70%);
      text-align: center;
    }
    .download-buttons {
      display: flex;
      justify-content: center;
      gap: 24px;
      flex-wrap: wrap;
      margin-top: 32px;
    }
    .platform-btn {
      background: rgba(17,24,50,0.8);
      backdrop-filter: blur(12px);
      border: 1px solid rgba(255,255,255,0.15);
      padding: 16px 32px;
      border-radius: 50px;
      color: white;
      font-weight: 600;
      transition: 0.3s;
    }
    .platform-btn:hover {
      border-color: var(--accent-green);
      box-shadow: 0 0 25px rgba(0,229,160,0.4);
    }
    
    /* 页脚 */
    .site-footer {
      background: #060B1A;
      padding: 60px 0 30px;
      border-top: 1px solid rgba(255,255,255,0.05);
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
    }
    @media (max-width: 768px) {
      .features-grid, .function-grid {
        grid-template-columns: 1fr;
      }
      .scene-row {
        flex-direction: column;
      }
      .footer-grid {
        grid-template-columns: 1fr;
      }
    }