Is it possible to add additional CSS to a toc plugin?

I’ve added a border-bottom to my links in the container area of my posts.

My issue is I don’t want the border-bottom to show on the table of contents (generated by writing [toc] in the editor).

The table of contents plugin used is “Easy Table of Contents” Version 1.7 | By Steven A. Zahm. When I go to edit the table of contents in Settings > Table of Contents, I don’t see a place to add custom CSS.

This is the code I used to add my border-bottom:

.container a {
border-bottom: 0.5px dashed;
}

Is there any way I can edit the CSS of this table of contents?

Thank you so much!

The page I need help with: [log in to see the link]