• 2em base font size is waaaaaay too large. I zoomed out to 50% and breathed a sigh of relief (and later dialed it back up to 67% which was tolerable too and probably more where it should be for such a thing).

• radio/checkbox need to be more distinct. I recommend a cross in the checkbox.

• Focus styles: you’ve killed the outlines on radio/checkbox and not replaced them with anything better, which is doubleplusungood, and where you haven’t touched the outline, the browser’s default clashes with your style.

• It could be fun to try replacing the border technique with feTurbulence + feDisplacementMap, not specifying the SVG’s viewBox/width/height, and using percentages for the sizes of things, allowing it to render at whatever size it needs to be, allowing you to avoid stretching in one direction or the other, though given the same seed the curves of the top and left edges will be consistent. A demo of much the underlying concept can be found within this WIP of my own that’s simultaneously overdone and underdone: https://temp.chrismorgan.info/2021-12-15-svg-drawn-filters-d..., look at the page edge, and fiddle with #paper-fuzzy-edge’s feTurbulence baseFrequency (e.g. 0.05) and feDisplacementMap’s scale (e.g. 20), also twiddling the #paper rect’s x/y/width/height.