The front page menu looks larger than dbb.net's now, which I don't mind at all (better that than too small), but the text in post bodies is still smaller. This is with Firefox, Opera, and Midori (Webkit), and I'm using the default theme that you get when not signed in since my account hasn't been activated yet.
I've looked over your *.css file. Let's go over some font best practices. I hope this doesn't come across as condescending--if it does, I apologize. I mean this to be strictly informal.
As far as font size is concerned, 1em == 100% is the user's preferred size. In modern browsers, this defaults to 16px == 12pt, but the user can change this in his preferences. So almost all content should be near 1em == 100%, without good reason, since this is just giving the user what he prefers. Some things should be larger (e.g. headers) and some thing can be smaller (e.g. navigation, subtitles, breadcrumbs, etc.), but the primary content should be near 100% (I'd push it as low as 0.8em). So when I read this, I'm a bit alarmed:
Code: Select all
body {
. . .
font-size: 70.5%; /* This sets the default font size to be equivalent to 10px */
. . .
}
This says to me that you want fonts, by default, to be 70% the size that I prefer! The other problem with this is that font em's/%'s styles are recursive. In other words, if you set the body to 50%, you're going to have to set something in the body to 200% to get back to 100%. So by setting the entire body to 70.5%, you're going to have to do some back-of-the-envelope math to even get back to 100%! That's a lot of hard and needless work! It gets even worse once you have multiple layers of em/% font styles nesting.
This is why, as a best practice, the body tag and large tags that comprise most of the page should be 100%. If you want individual elements in the body to be smaller, just make those individual elements smaller. If you want individual elements in the body to be larger, just make those individual elements larger. Note that styling the body tag (or any tag) with 100% font size is
equivalent to setting no font size at all, so this makes it easy peasy.
As another example, Firebug tells me that the calculated font size for posts is 14.6px. Since my default font size is 16px == 12pt, this tells me that this is still a bit smaller than my preferred size, which isn't necessarily bad. But this also tells me that at some point you've tried increasing the font size with something over 1em inside the body to try to offset the small recursive font size applied to the body. Ideally, the post body should just be set to specifically whatever size you want without recursively inheriting anything. The body tag should just be left at 100% by default. The containers the post body is in should be left at 100% by default. And the post body itself should be either left at 100% by default or set to something conservative, no less than 0.8em. This way, it makes it easy peasy to make sure that the post body is the desired size, and no awful algebra required to get it there.
The other issue is different fonts themselves. Looking over the css file, it looks like \"angry fruit salad.\" There seem to be font typos (veranda == verdana?) and a lot of different fonts for different contexts. As a best practice, I think you should replace all sans-serif font styles with a single ubiquitous font name followed by the generic name, e.g., font-family: Arial, sans-serif, or you would also do well with just the generic name. Do this again with monospace fonts, and continue to not use serif fonts. There's usually not a good reason to use different fonts on the same page with the notable exception of sans-serif vs. monospace and maybe a logo or very large headers. (FWIW, the dbb.net appears to use Arial).
Let me know if you have any questions.
edit: So back to post sizes, since it looks like the dbb.net uses 12pt, and since seafoam blue on black doesn't provide the best contrast
and figure out what the theme designer was doing. that persectage was actual set to 63.4 when I first started editing and yes I was chasing that font size since the first time you posted your question. 
(Please don't void any of the aforementioned...)