Yeah (i guess you mean epub), though in practice readers support only a tiny subset and epubs avoid using anything fancier than basic XHTML. Epubs that try to u

Yeah (i guess you mean epub), though in practice readers support only a tiny subset and epubs avoid using anything fancier than basic XHTML. Epubs that try to use fancy stuff (like most CSS outside of setting fonts - that readers can ignore either because they do not support it, or because the user wants to use another font) tend to not display correctly.