> (I am the website author & tech co-creator with Said Achmiz.)

I recently spend some time reading some parts of your website and found myself a little bit frustrated by the experience. I'm hesitant to criticise, since your site is of course your personal Memex, but count me as a n+1 with the opinion that there is room for improvement.

I too struggled with the hover popups. The boxy design isn’t very aesthetically pleasing – at the same time too much chrome, I think, and like the OP wrote, too less differentiation from the body of the page. For a casual reader the whole window management of those popups seems too much. And there is a certain lack of predicability of them. For one, only some links seem to have them, second, the delay to pop is just the right time of infuriating. A common occurrence of mine, when reading your pages, is the following: I'm scrolling down, start reading the next paragraph, then, without me doing something, suddenly a popup pops up. What did I do? Did I do something wrong? Why is that happening? Of course, the explanation is simple: while scrolling, my cursor landed on a link which has a link preview popup and the delay happens, presumably, because the network request fetched the preview. But it is still an UI change without any real and conscious user action on my part. The effect is that one has to be careful to read you page, knowing where one's cursor is, and where to put it as not to trigger anything. I ended up deactivating the popups and later using Reader mode, first your site's own, then later my own browser's.

(Aside: The gear icon in the top right seems invisible in my browser [Safari, MacOS]. There is still a clickable spot of white background, the rest of the menu works. I only found out that there is a setting because I was reading your site design pages, learned about that feature and compared with Chrome.)

I am, sorry to say, also not the biggest fan of the design. The main body imitates in a lot of ways a classical printed product. That, I think, is great. But the specialised parts – the examples, the backlinks, the digressions, the blockquotes, even the inline <code> fragments – are all in that boxy sub-design, sometimes even in boxes inside of boxes, which, I think, clashes with the book aesthetic. A common cited quote by designers is Design is perfect when there is nothing more to take away. In that vein I'd try to use far less boxes but more typography and whitespace for differentiation.

And: I'd use far less interactivity. Maybe that's just me, but my preferred interaction with web pages is simply scrolling, not clicking. That is both on Desktop (space bar) and on touch. Click to expand something, click to turn a carousel, etc. is always a touch annoying. My preferred textual web page is simply static, has no reflows, and has no other need for interaction other than scrolling down.

All of these changes are of course not necessary – there are far worse pages on the web. But maybe, if you sometimes in the future have time, interest and energy, you'll keep iterating. gwern.net has very good bones; but there is room for improvement.

Oh, and since this thread is about sidenotes: When I, in a default HD desktop viewport resolution put the zoom level up a notch, because I find the font size too small, the sidenote implementation decides that the sidenotes have less room and the sidenotes are gone. I can understand that at higher zoom levels, but at a simple 110% it's frustrating. Stuff like that is why me preferred sidenote implementations are a simple float:right with the notes displayed inline at a break point for smaller viewports.