Center Kanban page content?

[giacometti777]

I use Kanban boards for almost everything and wondered how I could keep Kanban page content centered like in the Minimal theme. Ive asked Gemini / Claude / ChatGPT but they generally recommend using CSS snippets which don't seem to work. Sorry for such a basic question but I am not sure what I would modify in the theme CSS to make it happen. Thanks in advance for any help!