If I have a paragraph marked up as
Code:
p(poem). 'Twas brillig, and the slithy toves...
and in extra CSS box have
Code:
.poem {padding-left:10%; padding-right:10%; text-indent:0; text-align: left; font-style: italic;}
Then the resulting epub html DOES keep the 'poem' classname
Code:
<p class="poem">‘Twas brillig, and the slithy toves...</p>
EDIT:
If I have another paragraph marked up as
Code:
p(poem)=. 'Twas brillig, and the slithy toves...
(Note the = center align)
Calibre also creates a .poem1 class with the same css as poem but also including the text-align:center; tags.