How to even out the fonts/sizes in the comment section of blogs?

Anyone know how to change the font size of the actual comment content?  It's much smaller than the name and like count, and would like the comment to be the main focus. 

Actually need help to create even sizing throughout the whole comment block? All the fonts the same in the comments section*** Also the "preview" is really far away from the button "Log your workout"? Anyone know how to change that?

Would love some CSS help!

Example page:

https://www.indoorphins.com/dailydb/v3/day1

#1. Add to Design > Custom CSS

div.comment-body * {
    font-size: 20px;
}

#2. Do you use Personal or Business Plan?