/* roulang page: index */
:root {
      /* 核心色彩系统 */
      --primary-deep: #0A1929;
      --primary-soft: #1A2F45;
      --accent-teal: #00C9A7;
      --accent-teal-hover: #00B392;
      --cta-orange: #FF6B35;
      --cta-orange-hover: #E55A2B;
      --bg-light: #F7F9FC;
      --card-white: #FFFFFF;
      --text-main: #1E293B;
      --text-secondary: #64748B;
      --border-light: #E2E8F0;
      --border-subtle: rgba(0,0,0,0.05);
      
      /* 圆角与阴影 */
      --radius-sm: 8px;
      --radius-md: 12px;
      --radius-lg: 16px;
      --shadow-card: 0 1px 3px rgba(0,0,0,0.06), 0 1px 2px rgba(0,0,0,0.04);
      --shadow-card-hover: 0 10px 25px rgba(0,0,0,0.08);
      --shadow-nav: 0 2px 8px rgba(0,0,0,0.04);
      
      /* 字体 */
      --font-stack: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", "Noto Sans SC", sans-serif;
      
      /* 间距 */
      --space-section: 80px;
      --space-card-padding: 24px;
    }
    
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    
    body {
      font-family: var(--font-stack);
      background-color: var(--bg-light);
      color: var(--text-main);
      line-height: 1.8;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }
    
    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
    }
    
    /* 排版层级 */
    h1, h2, h3 {
      font-weight: 700;
      line-height: 1.3;
    }
    
    h1 { font-size: 32px; }
    h2 { font-size: 24px; margin-bottom: 16px; }
    h3 { font-size: 20px; font-weight: 600; }
    
    a {
      text-decoration: none;
      color: inherit;
      transition: color 0.2s ease;
    }
    
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    
    button, .btn {
      cursor: pointer;
      font-family: inherit;
      border: none;
      background: none;
    }
    
    /* 导航 */
    .site-nav {
      position: sticky;
      top: 0;
      z-index: 100;
      background: rgba(255,255,255,0.95);
      backdrop-filter: blur(8px);
      height: 72px;
      display: flex;
      align-items: center;
      border-bottom: 1px solid var(--border-subtle);
      transition: box-shadow 0.3s ease;
    }
    
    .site-nav.scrolled {
      box-shadow: var(--shadow-nav);
    }
    
    .nav-container {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
    }
    
    .logo {
      display: flex;
      align-items: center;
      gap: 8px;
      font-weight: 700;
      font-size: 20px;
      color: var(--primary-deep);
    }
    
    .logo i {
      font-size: 24px;
      color: var(--accent-teal);
    }
    
    .nav-links {
      display: flex;
      gap: 32px;
      align-items: center;
    }
    
    .nav-links a {
      font-size: 15px;
      font-weight: 500;
      color: var(--text-secondary);
      position: relative;
      padding: 4px 0;
    }
    
    .nav-links a:hover,
    .nav-links a.active {
      color: var(--accent-teal);
    }
    
    .nav-cta {
      background: var(--accent-teal);
      color: white !important;
      padding: 8px 20px !important;
      border-radius: var(--radius-sm);
      font-weight: 600;
    }
    
    .nav-cta:hover {
      background: var(--accent-teal-hover);
    }
    
    /* 移动端菜单 */
    .menu-toggle {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
    }
    
    .menu-toggle span {
      width: 24px;
      height: 2px;
      background: var(--primary-deep);
      transition: 0.3s;
    }
    
    #menu-checkbox {
      display: none;
    }
    
    /* 区块间距 */
    section {
      padding: var(--space-section) 0;
    }
    
    /* 按钮系统 */
    .btn-primary {
      background: var(--accent-teal);
      color: white;
      padding: 12px 28px;
      border-radius: var(--radius-sm);
      font-weight: 700;
      font-size: 16px;
      letter-spacing: 0.5px;
      display: inline-flex;
      align-items: center;
      gap: 8px;
      transition: background 0.25s, box-shadow 0.25s;
    }
    
    .btn-primary:hover {
      background: var(--accent-teal-hover);
      box-shadow: 0 8px 16px rgba(0,201,167,0.25);
    }
    
    .btn-cta {
      background: var(--cta-orange);
      color: white;
      padding: 14px 32px;
      border-radius: var(--radius-sm);
      font-weight: 700;
      font-size: 16px;
      letter-spacing: 0.5px;
      transition: background 0.25s, box-shadow 0.25s;
    }
    
    .btn-cta:hover {
      background: var(--cta-orange-hover);
      box-shadow: 0 8px 20px rgba(255,107,53,0.3);
    }
    
    .btn-outline {
      background: transparent;
      border: 1px solid var(--accent-teal);
      color: var(--accent-teal);
      padding: 10px 24px;
      border-radius: var(--radius-sm);
      font-weight: 600;
    }
    
    .btn-outline:hover {
      background: rgba(0,201,167,0.05);
    }
    
    /* 卡片 */
    .card {
      background: var(--card-white);
      border-radius: var(--radius-md);
      padding: var(--space-card-padding);
      box-shadow: var(--shadow-card);
      transition: transform 0.25s ease, box-shadow 0.25s ease;
      height: 100%;
    }
    
    .card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-card-hover);
    }
    
    /* Hero */
    .hero {
      background: var(--primary-deep);
      color: white;
      position: relative;
      overflow: hidden;
      padding: 100px 0 120px;
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      background-blend-mode: overlay;
      background-color: rgba(10,25,41,0.85);
    }
    
    .hero-content {
      max-width: 700px;
      position: relative;
      z-index: 2;
    }
    
    .hero h1 {
      font-size: 40px;
      margin-bottom: 20px;
      line-height: 1.2;
    }
    
    .hero .subtitle {
      font-size: 18px;
      color: rgba(255,255,255,0.8);
      margin-bottom: 32px;
    }
    
    /* 痛点卡片网格 */
    .grid-3 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    
    .grid-2 {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 24px;
    }
    
    .grid-asym {
      display: grid;
      grid-template-columns: 1.2fr 0.8fr;
      gap: 24px;
    }
    
    /* 图标装饰 */
    .icon-circle {
      width: 48px;
      height: 48px;
      background: rgba(0,201,167,0.1);
      border-radius: 12px;
      display: flex;
      align-items: center;
      justify-content: center;
      color: var(--accent-teal);
      font-size: 24px;
      margin-bottom: 16px;
    }
    
    .stat-number {
      font-size: 36px;
      font-weight: 700;
      color: var(--accent-teal);
    }
    
    /* FAQ 手风琴 */
    .faq-item {
      background: var(--card-white);
      border-radius: var(--radius-md);
      margin-bottom: 12px;
      box-shadow: var(--shadow-card);
    }
    
    .faq-question {
      padding: 18px 24px;
      font-weight: 600;
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
      list-style: none;
    }
    
    .faq-answer {
      padding: 0 24px 18px;
      color: var(--text-secondary);
    }
    
    details[open] .faq-question i {
      transform: rotate(180deg);
    }
    
    /* 页脚 */
    .site-footer {
      background: var(--primary-deep);
      color: rgba(255,255,255,0.7);
      padding: 40px 0;
      font-size: 14px;
    }
    
    .footer-content {
      display: flex;
      justify-content: space-between;
      align-items: center;
      flex-wrap: wrap;
    }
    
    /* 响应式 */
    @media (max-width: 1024px) {
      .grid-3, .grid-asym {
        grid-template-columns: repeat(2, 1fr);
      }
    }
    
    @media (max-width: 768px) {
      :root {
        --space-section: 60px;
      }
      
      h1 { font-size: 28px; }
      h2 { font-size: 22px; }
      
      .nav-links {
        display: none;
        position: absolute;
        top: 72px;
        left: 0;
        width: 100%;
        background: white;
        flex-direction: column;
        padding: 20px;
        box-shadow: var(--shadow-nav);
      }
      
      #menu-checkbox:checked ~ .nav-links {
        display: flex;
      }
      
      .menu-toggle {
        display: flex;
      }
      
      .grid-3, .grid-2, .grid-asym {
        grid-template-columns: 1fr;
      }
      
      .hero h1 {
        font-size: 32px;
      }
      
      .footer-content {
        flex-direction: column;
        gap: 16px;
        text-align: center;
      }
    }