Virtual Japanese manuscript paper created purely with HTML and CSS, made for fun.
https://static.nya.nz/manuscript-paper
Manuscript paper is used generally for Japanese handwriting or nicely laid out longform articles, and I quite like the vertical writing style, so I thought I would check out how I could make a grid in the least number of HTML tags to fake it on a webpage.
Probably not the most exciting or unique thing in the world, but you can edit the text on the page and it also can be printed for handwriting practice!
Requires modern browser support for CSS3 writing mode, multiple backgrounds and linear gradients.
I would have used flexbox for the layout but the interactions with top-bottom, right-left text flow elements completely broke scrolling when the virtual paper overflowed. Oh well.