How to hide "Livestream" section and right sidebar (Channel list) in the publication view?

[Fauteck]

I'm customizing the public stream page and would like to fully hide the following elements:

The "Livestream" section below the video (showing viewers and duration)

The right sidebar including the channel list and preview thumbnail

I’ve tried CSS injection under "Design > Code injection", but the elements still appear or reflow unpredictably.
Is there a supported way (via config, environment variable, or theme override) to cleanly remove these UI parts?

Thanks in advance!