old_contents: module.exports = () => {
    return {
      '@border-radius-base': '3px',
      '@border-radius-sm': '2px',
      '@shadow-color': 'rgba(0,0,0,0.05)',
      '@shadow-1-down': '4px 4px 40px @shadow-color',
      '@border-color-split': '#f4f4f4',
      '@border-color-base': '#e5e5e5',
      '@menu-dark-bg': '#3e3e3e',
      '@text-color': '#666',
      '@font-family': 'monospace,-apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Helvetica, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", SimSun, sans-serif'
    }
  }
  
new_contents: module.exports = () => {
    return {
      '@border-radius-base': '3px',
      '@border-radius-sm': '2px',
      '@shadow-color': 'rgba(0,0,0,0.05)',
      '@shadow-1-down': '4px 4px 40px @shadow-color',
      '@border-color-split': '#f4f4f4',
      '@border-color-base': '#e5e5e5',
      '@menu-dark-bg': '#3e3e3e',
      '@text-color': '#666',
      '@font-family': '-apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Helvetica, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", SimSun, sans-serif'
    }
  }
  
subject: Adjust theme font-family