I had been thinking of including the static parts into an object, but it would require a duplication of the CSS required by the non-static parts.

I was already afraid that splitting the menu in a constant and a variable part would give trouble. But it might be possible to treat the entire menu as variable, and put it externally. After all, the menu is not very variable; a given user will only need two different versions of it, one where he is signed in, and the other where no one is signed in.

I have never seen a PHP script, but I imagine the msdisplay.php looks something like this:

GenerateHeader();
GenerateMenuBar(USER);
GenerateAds();
GenerateArticle(SUBJECT);

The GenerateMenuBar part could be moved to a separate script, menu.php (say), which would also generate the styling instructions. The output of this script would then be included as an <object> in the main page. So the msdisplay.php script would become

GenerateHeader();
Generate('<object data="menu.php?user=USER"></object>');
GenerateAds();
GenerateArticle(SUBJECT);

and tne menu.php would contain

GenerateMenuBar($user);

The main script would only generate two different menu URLs in the <object> tag for a given user XXX: menu.php?user=none, and menu.php?user=XXX, and the browser would cache both, and from then on would only use these cached versions, not accessing the menu.php on the server anymore.

[Edit] Forget it, this idea does not work. I made a 'mockup' of the CVP website by copying the /g/global.css style file and all icons in /index (and /ads/showads.js) to my Linux VM, and put the page source of /invention/werewolf-chess on a file with .html extension. Showing the latter in my browser gives a reasnable reproduction of how the page looks on the site itself. (For reasons I have not identified yet the ebay ad below the menu bar stays blank, although the ebay ad in the banner does appear). This does result in a fully operational menu bar (at least as far as opening menus and sub-menus; when you actually select a menu item, the link is usually broken, as it points to a onsite file/script that I did not copy).

This allowed me to experiment with the menu bar. It was possible to migrate the menu section of the page source together with its styling to an external html file, and include that as an object (although that gave a margin of about 5 pixels around it that I did not managed to suppress yet). Such a wrapped menu bar responds to mouse hover for popping up the menus. But what kills the idea is that the menus that pop up are confined to the size reserved for the <object>:

 

I added  max-width: 100%;  to the CSS for the ARTICLE element, and it seems to have fixed the problem.

Good trick. I will try that in the diagram design wizard too. For some reason long lines in a <pre> element (like what I use to present the generated HTML code in the wizard) now force the element wide enough to completely contain them, rather than wrapping. That didn't use to be a problem in the past. But restricting the width as a percentage of the parent element might combat this problem.