Using CSS to adjust font-weight based on screen width.
You will need to rework the measurements so that a smaller viewport width would be assigned a slightly larger font-weight. See this side-by-side comparison of Geist in medium weight at a smaller screen size.
This implies using a variable font:
- Google Fonts - Introducing variable fonts
- v-fonts.com - Resource for finding and trying variable fonts
Legibility after adjustments will vary based on the font used.
- Temani Afif: Update CSS variables using range slider
- Jane Ori: CSS Type Casting to Numeric: tan(atan2()) Scalars
- Mandy Michael: Fluid Font Weight with Viewport Size - Variable Fonts