How do I fix breakpoint font sizes with custom CSS? (I’m using the NOLL template)

Site URL: https://noll-demo.squarespace.com/

I love how my site looks with the NOLL template, but everything looks clunky and unrefined real quick after the first breakpoint, which is usually when I view my site on tablet or with a narrowed web browser.

Problem

The main problem for me is the unnatural increase in font size. It becomes almost twice as large than my default font size after the first breakpoint. 
 

Desired Solution

• SOLUTION 1: Make the tablet version / first breakpoint version of my website look like the default full screen browser version.
• SOLUTION 2: Use custom CSS to adjust the font size within the first breakpoint.

However... is this even possible?

I’ve tried to Google this but I’ve found nothing on how to fix it. I understand some other theme templates have breakpoint customisation within the settings panel, unfortunately the NOLL template doesn’t have this so I’m hoping for some CSS code to fix it under the hood. 

Thank you to anyone that can help!

Hi. Do you still need help on this?