How to fix text width for mobile on Flow theme?

Hi,
I am using the Flow theme. On desktop, the Glossary page looks fine but on mobile it is too wide/get’s cut off. How do I limit the width on mobile? I tried to use code from a previous answer but it told me to look for a theme.css.liquid page which I don’t have. This code just has a theme.liquid page and when I pasted it at the bottom it just showed as writing under the footer.

Hi @Baycoffee , go to edit code > assets > timber.scss.css and add this:

@media screen and (max-width: 768px) {
.grid, .grid--rev, .grid--full, .grid-uniform {
    margin: 0!important;
}
}

Here is the result: