I swapped out the Lectora generated buttons for graphical buttons (PNGs) I created in Inkscape. I still had the same problem with things coming out “fuzzy”. It turns out this was caused by the “Scale to fit” option in the Publish window. When I turn that option off, and re-publish I don’t have the same issue.
With graphical buttons this makes a little sense, as the more you scale the PNGs you’re likely to get distortion. PNGs, JPGs, etc… don’t always scale well. Although, I shall admit I thought it was a bit strange that the published buttons appear in SVG <PATH> tags, and the graphic is used as a background fill. I should think a standard tag with a bit of CSS would have been sufficient to render them. I’m sure you have your reasons for doing it this way. (Probably a backwards-compatibility thing with IE or something.)
With the Lectora generated buttons, this phenomena does perplex me a little bit. I didn’t look at the coding of the Lectora generated buttons that in-depth, but if they’re truly rendered using SVG I should think they would scale better with no blur. #Strange
In either case, still no shadows on publish.