Lessee here...
Looking at the HTML:* Drop all support for IE < 8. IE 9-11 will either keep up, or miss a few features, and you can safely ignore them. IE 8, 9, & 10 make up 0.7% of the All The Tropes user base, while IE 11 is 5%.* No uppercase tags pls k tx* Except this one: * Whoa a main page webring. Did their interface change?* Easily the most dated thing on the page is the text-on-image part of the menus. Even if you don't redesign, put ordinary text and use a CSS background image. This will look way clearer on highres displays* The GURPS Werewolf item looks really strange in the menu. That's
because you're using non-breaking spaces for layout. Use CSS instead.* The webring on the Greendale page looks like another questionable thing. Also is this the same Greendale as in
Community? That would explain so much.
Features:* Mobile reading mode with a custom mobile CSS? Don't make it too fancy because uh...
* Alternate dark-on-light mode, like ff.net has would be nice. Or dark brown on light tan, like Apple's Sepia mode.* A font-size adjuster -- mainly useful on mobile, same idea. Both of these are pretty easy to implement.* Comments sections are deals with the devil. Don't give in; we have a forum.
I'm not really sure what your hosting setup looks like, and how flexible it is. If it were me, I might set up something with a simple combination of Perl Dancer and Template Toolkit. Bootstrap seems pretty popular (and this is why a lot of websites look the same these days). You could probably set up a simple menu transclusion system using basic PHP. I am actually pretty terrible at keeping up with modern frameworks. You might just want to pick up something that you want to learn and do it for the sake of learning that.
jQuery is pretty simple really, and the docs are not that hard to read -- it's just being aware of features. Remember that there are useful jQuery libraries out there, like
this one. Underscore is also a thing but I've never bothered to learn it.
Hard mode suggestion: figure out a way to automatically include footnotes inline, and hide the footnotes until a button is clicked. Mainly suggesting because I'm thinking of doing this with EPU on the EPUBs I'm making. Oh, there's another one, HTML that could be used to compile an ebook easily!
Finally, I'd do something that you could deploy and backup a change in only one or two steps. I keep saying git is great for creative writing too.
-- ∇×V