Losing background image and font configuration when exporting to HTML

[ReichYang]

Hi, I want to have a slide with a background image and customized fonts. I configured the background image and stuff in the nbextension configurator and it works when I run the slides. However, when I export them using nbconvert --slides, all the configurations are lost.

Is there a way to retain the config and make the exported HTML the same as what can be seen when doing a slideshow?