Set a hard base font size of 14px

At least two people on Apple OS X have reported that the release
announcement font is too small, apparently because their browsers
default to a 14pt font size instead of 16pt.

I'm afraid people with different visual requirements will have to use
zooming, custom stylesheets, or a screen magnifier.
New 1280x768 screenshots, including one for the titlescreen

These replace the previous 1024x768 screenshots. In the future we'll use
1280x768 screenshots for everything else too.

Screenshots.