在主题方面遇到困难

[dax (Daniela)]

@alltiagocom

Where do I check this?

Your site settings.

@alltiagocom

I have my device set to dark, but for example I am able to change to light here on the Discourse forum.

That setting is not enabled on Meta

@alltiagocom

And why can’t I see the dropdown to change the theme in the sidebar?

Because you need to install the proper theme component, Sidebar Theme Toggle