Change theme of plotly dash components dynamically

I’m new to plotly dash, and my question is about changing the CSS of all dcc components, or html components of page. My scenario is in “assets” folder there are several .css files which all of them have unique class names, but different attributes. As an example, .p class with different backgrounds color. Now there is a dropdown in the page which shows these different theme files, if user change the value, all components themes change. I found out that plotly set CSS from the last CSS file(alphabetic order) at first load, but don’t know how change it hot reload.