I have switched back to a serifed font (which, honestly, I never meant to get rid of in the first place) and have embedded the comments so that they no longer appear in a white pop-up window. These changes eliminate two small problems with the new design.
I recognize that, with three columns, I squeeze the middle post column a bit and also that it makes the site less legible for readers using certain browsers and devices. That's something I'd like to fix, but I also really like having that extra column. What I'm considering now is shrinking the column sizes somewhat but I don't know if that'll solve the problem.
As for the white on black text, I'm willing to make some alterations to that. However, I really do prefer a dark overall look to the blog. So, if you're someone who finds the current color scheme problematic, I'd appreciate some suggestions of alternatives that don't involve a white background and black text. I'd be even more appreciative if you could provide some HTML color codes to assist me.
Thanks again for your patience as I work to get this right.