What I suggested would require some understanding of HTML and CSS, with this understanding, you’d use your browser’s inspector to check for the CSS class and make edits to fit what you’d want. You can then add these edits to your site using a theme-component.
The link I shared shows a theme-component that was created for an almost similar purpose so you could look through it and get an idea of how to create one for your site.
Let me also share some resources to help you better understand how to edit and customise the Discourse UI.
Here are some resources.