/* roulang page: index */
/* ----- CSS 设计变量 & 全局重置 ----- */
    :root {
      --primary-deep: #0A2540;
      --accent-green: #00C49A;
      --accent-green-hover: #00A884;
      --bg-light: #F8FAFC;
      --card-white: #FFFFFF;
      --text-main: #1E293B;
      --text-muted: #64748B;
      --highlight-orange: #FF6B35;
      --border-light: #E2E8F0;
      --shadow-sm: 0 4px 12px rgba(10, 37, 64, 0.06);
      --shadow-md: 0 8px 24px rgba(10, 37, 64, 0.12);
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-input: 6px;
      --font-title: 'PingFang SC', 'Microsoft YaHei', 'Noto Sans SC', 'Inter', sans-serif;
      --font-body: 'PingFang SC', 'Microsoft YaHei', 'Noto Sans SC', 'Inter', sans-serif;
      --transition-smooth: all 0.2s ease;
      --max-width: 1200px;
      --nav-height: 72px;
    }
    
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    
    body {
      font-family: var(--font-body);
      background-color: var(--bg-light);
      color: var(--text-main);
      line-height: 1.7;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }
    
    .container {
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 24px;
    }
    
    a {
      text-decoration: none;
      color: inherit;
      transition: var(--transition-smooth);
    }
    
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    
    button, .btn {
      cursor: pointer;
      font-family: var(--font-body);
      border: none;
      background: none;
      transition: var(--transition-smooth);
    }
    
    /* 标题字体 */
    h1, h2, h3, .stats-number {
      font-family: var(--font-title);
      font-weight: 700;
    }
    
    /* 实用工具类 */
    .section-padding {
      padding: 80px 0;
    }
    
    /* ----- 导航栏 (固定白底平台导航) ----- */
    .site-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: var(--nav-height);
      background: rgba(255, 255, 255, 0.92);
      backdrop-filter: blur(12px);
      box-shadow: 0 1px 8px rgba(10, 37, 64, 0.04);
      z-index: 100;
      display: flex;
      align-items: center;
    }
    
    .header-inner {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
    }
    
    .logo {
      font-family: var(--font-title);
      font-size: 1.8rem;
      font-weight: 700;
      color: var(--primary-deep);
      letter-spacing: 1px;
      display: flex;
      align-items: center;
      gap: 8px;
    }
    .logo i {
      color: var(--accent-green);
      font-size: 2rem;
    }
    
    .nav-menu {
      display: flex;
      align-items: center;
      gap: 32px;
    }
    
    .nav-menu a {
      font-weight: 500;
      color: var(--text-main);
      font-size: 1rem;
      padding: 8px 0;
      border-bottom: 2px solid transparent;
    }
    .nav-menu a:hover,
    .nav-menu a.active {
      color: var(--accent-green);
      border-bottom-color: var(--accent-green);
    }
    
    .mobile-toggle {
      display: none;
      font-size: 1.8rem;
      color: var(--primary-deep);
      background: transparent;
      border: none;
    }
    
    /* 移动端导航面板 */
    .mobile-nav {
      display: none;
      position: fixed;
      top: var(--nav-height);
      left: 0;
      width: 100%;
      background: white;
      box-shadow: var(--shadow-md);
      flex-direction: column;
      padding: 24px;
      gap: 20px;
      z-index: 99;
      backdrop-filter: blur(10px);
    }
    .mobile-nav a {
      font-size: 1.2rem;
      font-weight: 600;
      color: var(--primary-deep);
      padding: 8px 0;
      border-bottom: 1px solid var(--border-light);
    }
    
    /* ----- 按钮体系 ----- */
    .btn-primary {
      background: var(--accent-green);
      color: white;
      border-radius: var(--radius-btn);
      padding: 14px 32px;
      font-weight: 600;
      font-size: 1rem;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      box-shadow: 0 4px 10px rgba(0, 196, 154, 0.25);
    }
    .btn-primary:hover {
      background: var(--accent-green-hover);
      transform: translateY(-1px);
      box-shadow: 0 8px 18px rgba(0, 196, 154, 0.35);
    }
    
    .btn-outline {
      border: 2px solid var(--primary-deep);
      color: var(--primary-deep);
      background: transparent;
      border-radius: var(--radius-btn);
      padding: 14px 32px;
      font-weight: 600;
    }
    .btn-outline:hover {
      background: var(--primary-deep);
      color: white;
    }
    
    /* ----- 首屏 Hero ----- */
    .hero {
      padding: 140px 0 80px;
      background-color: var(--bg-light);
      position: relative;
      overflow: hidden;
    }
    .hero .container {
      display: flex;
      align-items: center;
      gap: 40px;
    }
    .hero-left {
      flex: 1 1 50%;
    }
    .hero-right {
      flex: 1 1 50%;
      display: flex;
      justify-content: center;
      align-items: center;
    }
    .hero-right img {
      max-height: 480px;
      border-radius: 32px;
      box-shadow: 0 24px 48px rgba(10, 37, 64, 0.12);
    }
    h1 {
      font-size: clamp(2.2rem, 5vw, 3rem);
      line-height: 1.2;
      color: var(--primary-deep);
      margin-bottom: 20px;
    }
    .hero-sub {
      font-size: 1.2rem;
      color: var(--text-muted);
      margin-bottom: 32px;
      max-width: 480px;
    }
    .hero-buttons {
      display: flex;
      flex-wrap: wrap;
      gap: 16px;
    }
    
    /* ----- 版块标题 ----- */
    .section-title {
      text-align: center;
      margin-bottom: 56px;
    }
    .section-title h2 {
      font-size: 2.2rem;
      color: var(--primary-deep);
      margin-bottom: 12px;
    }
    .section-title p {
      color: var(--text-muted);
      font-size: 1.1rem;
    }
    
    /* ----- 核心优势 (不对称网格) ----- */
    .advantages-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 28px;
    }
    .adv-card {
      background: var(--card-white);
      border-radius: var(--radius-card);
      padding: 36px 28px;
      box-shadow: var(--shadow-sm);
      transition: var(--transition-smooth);
      display: flex;
      flex-direction: column;
      align-items: flex-start;
      border: 1px solid rgba(0,0,0,0.02);
    }
    .adv-card:hover {
      box-shadow: var(--shadow-md);
      transform: translateY(-4px);
    }
    .adv-icon {
      font-size: 2.4rem;
      color: var(--accent-green);
      margin-bottom: 20px;
      background: rgba(0,196,154,0.08);
      padding: 12px;
      border-radius: 12px;
    }
    .adv-card h3 {
      font-size: 1.5rem;
      margin-bottom: 12px;
      color: var(--primary-deep);
    }
    .adv-card p {
      color: var(--text-muted);
    }
    
    /* ----- 功能分组 (左右交替) ----- */
    .feature-row {
      display: flex;
      align-items: center;
      gap: 60px;
      margin-bottom: 80px;
    }
    .feature-row.reverse {
      flex-direction: row-reverse;
    }
    .feature-text {
      flex: 1;
    }
    .feature-visual {
      flex: 1;
      background: #f1f5f9;
      border-radius: 24px;
      overflow: hidden;
      display: flex;
      justify-content: center;
      align-items: center;
      padding: 24px;
      box-shadow: var(--shadow-sm);
    }
    .feature-visual img {
      border-radius: 16px;
    }
    .feature-list {
      list-style: none;
      margin-top: 24px;
    }
    .feature-list li {
      display: flex;
      align-items: center;
      gap: 12px;
      margin-bottom: 16px;
      font-weight: 500;
      color: var(--text-main);
    }
    .feature-list i {
      color: var(--accent-green);
      font-size: 1.2rem;
    }
    
    /* ----- 使用场景卡片 ----- */
    .scenarios-grid {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 28px;
    }
    .scenario-card {
      background: var(--card-white);
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
      transition: var(--transition-smooth);
    }
    .scenario-card:hover {
      box-shadow: var(--shadow-md);
      transform: scale(1.01);
    }
    .scenario-img {
      height: 220px;
      overflow: hidden;
    }
    .scenario-img img {
      width: 100%;
      height: 100%;
      object-fit: cover;
      transition: transform 0.3s;
    }
    .scenario-card:hover .scenario-img img {
      transform: scale(1.05);
    }
    .scenario-content {
      padding: 24px;
    }
    .scenario-content h3 {
      font-size: 1.5rem;
      margin-bottom: 8px;
    }
    
    /* ----- 成功案例/数据 ----- */
    .stats-row {
      display: flex;
      gap: 40px;
      flex-wrap: wrap;
    }
    .stats-left {
      flex: 1;
      display: flex;
      flex-direction: column;
      gap: 32px;
    }
    .stat-item .stats-number {
      font-size: 3rem;
      color: var(--accent-green);
      font-weight: 700;
    }
    .stat-label {
      color: var(--text-muted);
    }
    .quote-card {
      background: var(--primary-deep);
      color: white;
      padding: 36px;
      border-radius: var(--radius-card);
      flex: 1;
      min-width: 260px;
    }
    .quote-text {
      font-size: 1.3rem;
      font-style: italic;
      margin-bottom: 16px;
    }
    
    /* ----- FAQ 手风琴 ----- */
    .faq-item {
      border-bottom: 1px solid var(--border-light);
      margin-bottom: 8px;
    }
    .faq-question {
      background: transparent;
      width: 100%;
      text-align: left;
      padding: 20px 16px;
      font-size: 1.1rem;
      font-weight: 600;
      display: flex;
      justify-content: space-between;
      align-items: center;
      color: var(--primary-deep);
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s ease, background 0.2s;
      background: white;
      padding: 0 16px;
      color: var(--text-muted);
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      padding: 16px;
      background: #F1F5F9;
    }
    .faq-item.active .faq-icon {
      transform: rotate(180deg);
    }
    
    /* ----- CTA 横幅 ----- */
    .cta-banner {
      background: linear-gradient(135deg, #0A2540 0%, #0f3460 100%);
      border-radius: 24px;
      padding: 64px 48px;
      text-align: center;
      color: white;
      margin: 40px 0;
    }
    .cta-banner h2 {
      font-size: 2.2rem;
      margin-bottom: 16px;
    }
    
    /* ----- 页脚 ----- */
    .footer {
      background: var(--primary-deep);
      color: #CBD5E1;
      padding: 60px 0 30px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
      margin-bottom: 40px;
    }
    .footer a:hover {
      color: var(--accent-green);
    }
    
    @media (max-width: 1024px) {
      .advantages-grid { grid-template-columns: repeat(2,1fr); }
      .feature-row { flex-direction: column; gap: 32px; }
      .feature-row.reverse { flex-direction: column; }
    }
    
    @media (max-width: 768px) {
      .nav-menu { display: none; }
      .mobile-toggle { display: block; }
      .mobile-nav.active { display: flex; }
      .hero .container { flex-direction: column; }
      .advantages-grid { grid-template-columns: 1fr; }
      .scenarios-grid { grid-template-columns: 1fr; }
      .footer-grid { grid-template-columns: 1fr 1fr; }
      .stats-row { flex-direction: column; }
    }