Thanks for the demo. It seems to work well.
Is this easily adapted to higher resolution monitors as well? I haven't tried to understand you code for this page.
Like I said, its a compromise. If you want the actual content to fit on a 480x600 screen, and if you do not want the users to have to scroll vertically or horizontally, you can only have 480x600 pixels worth of content on the page. That's roughly 2K or so of text. So to "fill" a larger window you need to have increasing screen acreage filled by headers, footers and whatever! Now you could in theory do that right up to 1920x1080, but you'd probably want to put more content on the page if you did. But if you do that, you will have to scroll the text on anything less than a PC screen. So, yes, it can be done, but there are compromises to be made!
Another point, I chose the height of 600 pixels to fit on the most popular PC screens which are (1366x720). I.e. I've allowed 120px for the browser header etc. That's only a rough estimate, but you certainly can't go much large than that without a significant proportion of users having to scroll the page. So to get more content on the page, you will need to use greater width for content. But excessively long lines of text become less readable, so you may then need to adopt a columnar format. Which, again, is not impossible, but it does raise its own issues.
Basically, I was just showing you what can be done to fit a reasonable quantity of content on a wide range of screen/window sizes.