Resizing the window reduces the user's desired font size: I don't know how many web readability rules this breaks.
If the user then increases the font size, the web page obliges, expanding beyond the window boundary, yet doesn't provide a horizontal scroller! Very bad.
The thing is: Tufte's style isn't designed for webpages. It's designed for books. Books have defined margins, a fixed size, and pages with a defined length. (Good) web pages don't necessarily have any of that. This is where sidenotes fall down, for example: the CSS author has to jump through a variety of hoops, breaking various conventions, in order to make them usable when the user narrows his window width.
If the user then increases the font size, the web page obliges, expanding beyond the window boundary, yet doesn't provide a horizontal scroller! Very bad.
The thing is: Tufte's style isn't designed for webpages. It's designed for books. Books have defined margins, a fixed size, and pages with a defined length. (Good) web pages don't necessarily have any of that. This is where sidenotes fall down, for example: the CSS author has to jump through a variety of hoops, breaking various conventions, in order to make them usable when the user narrows his window width.