I never said it can't be done. Yes, I realize I've taken this discussion outside the scope of what the OP intended. That's because I'm interested in learning how one would format such poems.
How far will CSS/HTML translate into other formats? If I'm setting type for a printed book, I pick the font and style. In a static HTML page, I could even get by with non-breaking space characters and not use CSS.
But what about devices that allow the user to pick different fonts? Even a font change could break the formatting of a poem.
If you formatted a poem (or any text) using advanced CSS techniques, such as putting each line in a div and using float and clear, or using so-called "sandbag divs" (
technique illustrated here) what happens when that gets converted to an e-book format?