/* roulang page: index */
/* ----- 设计变量 :root 全局配置 ----- */
    :root {
      /* 主色与辅色调 */
      --primary-orange: #F15A24;
      --primary-orange-deep: #D84315;
      --secondary-black: #1A1A1A;
      --warm-white: #F7F5F0;
      --gold-accent: #D4A843;
      --gold-accent-dark: #B4882C;
      
      /* 状态色 */
      --success-green: #2E7D32;
      --alert-red: #C62828;
      
      /* 背景衍生 */
      --bg-body: #F7F5F0;
      --bg-card: #FFFFFF;
      --bg-dark-card: #2A2A2A;
      --bg-footer: #1A1A1A;
      --text-primary: #1A1A1A;
      --text-secondary: #4B4B4B;
      --text-on-dark: rgba(255,255,255,0.9);
      --border-light: #E2E2E0;
      
      /* 圆角、阴影、间距系统 */
      --radius-sm: 8px;
      --radius-md: 12px;
      --radius-lg: 20px;
      --shadow-card: 0 4px 12px rgba(26,26,26,0.08);
      --shadow-card-hover: 0 12px 28px rgba(26,26,26,0.15);
      --shadow-nav: 0 2px 12px rgba(0,0,0,0.06);
      
      --font-sans: "Inter", -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      --font-mono: "Roboto Mono", "Courier New", monospace;
      
      --section-gap-desktop: 120px;
      --section-gap-tablet: 80px;
      --section-gap-mobile: 60px;
      --container-max: 1280px;
      --container-padding: 24px;
    }
    
    /* ----- 基础重置与全局样式 ----- */
    *, *::before, *::after {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }
    
    html {
      scroll-behavior: smooth;
      font-size: 17px;
    }
    
    body {
      font-family: var(--font-sans);
      background-color: var(--bg-body);
      color: var(--text-primary);
      line-height: 1.75;
      -webkit-font-smoothing: antialiased;
      -moz-osx-font-smoothing: grayscale;
      overflow-x: hidden;
    }
    
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    
    a {
      text-decoration: none;
      color: inherit;
      transition: color 0.2s, opacity 0.2s;
    }
    
    button, input, textarea {
      font-family: inherit;
      font-size: 1rem;
      border: none;
      outline: none;
      background: transparent;
    }
    
    .container {
      width: 100%;
      max-width: var(--container-max);
      margin: 0 auto;
      padding: 0 var(--container-padding);
    }
    
    /* 板块常规间距 */
    .section {
      padding-top: var(--section-gap-desktop);
      padding-bottom: var(--section-gap-desktop);
    }
    
    /* Header 样式 (沉浸式透明→滚动变白) */
    .site-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      background: transparent;
      z-index: 999;
      transition: background 0.25s ease, box-shadow 0.25s ease;
      padding-top: 12px;
      padding-bottom: 12px;
    }
    .site-header.scrolled {
      background-color: #fff;
      box-shadow: var(--shadow-nav);
    }
    .header-inner {
      display: flex;
      align-items: center;
      justify-content: space-between;
      max-width: var(--container-max);
      margin: 0 auto;
      padding: 0 var(--container-padding);
    }
    .logo {
      display: flex;
      align-items: center;
      font-weight: 700;
      font-size: 1.65rem;
      color: #fff;
      letter-spacing: 1px;
      transition: color 0.25s;
    }
    .logo-icon {
      width: 32px;
      height: 32px;
      background: var(--gold-accent);
      border-radius: 8px;
      margin-right: 10px;
      display: flex;
      align-items: center;
      justify-content: center;
      color: #1A1A1A;
      font-weight: 800;
    }
    .scrolled .logo {
      color: var(--secondary-black);
    }
    .nav-menu {
      display: flex;
      gap: 28px;
      align-items: center;
    }
    .nav-link {
      font-weight: 500;
      color: rgba(255,255,255,0.9);
      position: relative;
      font-size: 1rem;
    }
    .scrolled .nav-link {
      color: var(--text-primary);
    }
    .nav-link:hover {
      color: var(--primary-orange);
    }
    .nav-cta {
      background: var(--primary-orange);
      color: white !important;
      padding: 0.6rem 1.5rem;
      border-radius: var(--radius-sm);
      font-weight: 600;
      transition: 0.2s;
      margin-left: 12px;
    }
    .scrolled .nav-cta {
      color: white !important;
    }
    .nav-cta:hover {
      background: var(--primary-orange-deep);
      color: white !important;
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
    }
    .bar {
      width: 25px;
      height: 2px;
      background: white;
      transition: 0.2s;
    }
    .scrolled .bar {
      background: var(--secondary-black);
    }
    
    /* Hero 区块 (背景使用 backpic) */
    #hero {
      min-height: 95vh;
      display: flex;
      align-items: center;
      background: linear-gradient(135deg, rgba(26,26,26,0.7) 0%, rgba(26,26,26,0.4) 70%), url('/assets/images/backpic/back-2.webp') center/cover no-repeat;
      position: relative;
    }
    .hero-content {
      max-width: 640px;
      color: white;
    }
    .hero-title {
      font-size: 3.6rem;
      font-weight: 800;
      line-height: 1.2;
      letter-spacing: 0.8px;
      margin-bottom: 1.2rem;
    }
    .hero-highlight {
      color: var(--gold-accent);
    }
    .hero-lead {
      font-size: 1.35rem;
      margin-bottom: 2.3rem;
      opacity: 0.9;
      font-weight: 400;
    }
    
    /* 数据看板 深色背景 */
    .dashboard-dark {
      background: var(--secondary-black);
    }
    .stats-grid {
      display: grid;
      grid-template-columns: repeat(4,1fr);
      gap: 20px;
    }
    .stat-card {
      background: #2A2A2A;
      border-radius: var(--radius-md);
      padding: 28px 20px;
      text-align: left;
    }
    .stat-number {
      font-family: var(--font-mono);
      font-size: 3.3rem;
      font-weight: 700;
      color: var(--primary-orange);
      margin-bottom: 8px;
    }
    
    /* 服务矩阵 - 非对称网格 */
    .services-flex {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr;
      gap: 24px;
    }
    .service-card-big {
      background: var(--primary-orange);
      color: white;
      border-radius: var(--radius-lg);
      padding: 32px;
      display: flex;
      flex-direction: column;
      justify-content: flex-end;
    }
    .service-card {
      background: white;
      border-radius: var(--radius-md);
      padding: 24px;
      box-shadow: var(--shadow-card);
    }
    
    /* 方案对比 / 表格比较 */
    .compare-grid {
      display: grid;
      grid-template-columns: repeat(3,1fr);
      gap: 24px;
    }
    
    .feature-item i { margin-right: 8px; }
    
    /* 常见问题手风琴 */
    .faq-item {
      background: white;
      margin-bottom: 12px;
      border-radius: var(--radius-md);
    }
    .faq-question {
      padding: 20px 24px;
      font-weight: 600;
      border-left: 6px solid var(--primary-orange);
      cursor: pointer;
      display: flex;
      justify-content: space-between;
    }
    
    /* 图表按钮对齐等...已在下方同步响应式处理 */
    
    /* ----- 响应式设计 ----- */
    @media (max-width: 1024px) {
      .stats-grid { grid-template-columns: repeat(2,1fr); }
      .services-flex { grid-template-columns: 1fr 1fr; }
      .compare-grid { grid-template-columns: 1fr; }
    }
    @media (max-width: 768px) {
      .nav-menu { display: none; position: fixed; top: 0; right: 0; width: 80%; height: 100vh; background: var(--secondary-black); flex-direction: column; padding: 120px 30px; }
      .hamburger { display: flex; }
      .hero-title { font-size: 2.8rem; }
      .stats-grid { grid-template-columns: 1fr 1fr; }
    }