code: def render_theming_css():
      
      css = getattr(settings, 'ADMIN_TOOLS_THEMING_CSS', False)
      if not css:
          css = '/'.join(['admin_tools', 'css', 'theming.css'])
      return mark_safe(
          '<link rel="stylesheet" type="text/css" media="screen" href="%s" />' %
          staticfiles_storage.url(css)
      )
docs: Template tag that renders the needed css files for the theming app.