This style demonstrates why mixing serif and sans-serif fonts is not generally a good idea (unless it's only me getting that?). Also, the colour scheme lacks effective contrast; I'd try making the background grey darker so the yellow borders don't blend into it, failing that it might be better off white. Lastly, two small things, but along the top,
Home,
Blogs and
Chat are underlined (I mean
like this, not the yellow lines), but
Oekaki is not; and the second matter, the
quick reply button's text goes into the yellow bar on its right edge, rather unsightly. Sorry, but your style really does seem poorly thought out.
Well, actually, it would look the same if it was in .png. People simply have negative views on .jpg because of pixel art which should be saved as .png to preserve hard edges, but normal images work fine saved as a high quality .jpg.
Watch out there, high quality JPEGs can end up with larger filesizes than PNGs, and yet still minor artifacting.
It's called portable
network graphics for a reason. Just saying, though — usually JPEGs are smaller.
