Responsive QR Code using CSS Flexbox, CSS Variables, w/ auto dark mode

I'm not sure if it's a good idea to include auto dark mode within a website, and i am conflicted about using filters to make the QR image appear easier on the eyes when in dark mode. Should i keep doing it this way going forward, or should i abandon the thought?

Another thing i'd like to know is if i should keep using CSS Resets, or move onto html5boilerplate and alike.