Content window width and hiding content

[gustavengstrom]

Hi, I am new to MyST so forgive my ignorance but would be great if someone could provide some insights on the following questions.

1. Is it possible to increase the width of the content window? The default in the article theme is very narrow and when displaying a subfigures with two columns it is very difficult to see the labels. I presume this might be possible using a style file but I have not found which css class to target.
2. Is it possible to hide markdown files from MyST when running myst start. Or perhaps hide specific folders from showing up in the ToC?