PLEASE can someone help me with MOODLE

Hi friends, I'm new to the community, I'm turning to you as experts.

I want to apply the style of a column in the moove theme only to books,

I would like to hide the table of contents column, I use Moodle 3.8

Or I would like to use this tag but it doesn't work, that is, the theme comes with 3 columns, I would only like to use one.

This configuration is the one that is applied when you have a column width of 767 pixels.

I really appreciate your suggestions and help.