It's really rather sad that people, even people advertising a TUI drawing library that draws boxes, don't get Unicode block graphic and line drawing characters to the extent that the box lines in the "title on bottom" example here don't join up.

This is, ironically, because https://blog.orhun.dev/site.css also sets a font-size and a line-height that make the explicit list of fonts that it selects not work. I take these out and go back to using the WWW browser's own pre-supplied monospace fonts and styles for <pre>, and the example appears correctly.