applying style to single post page only

I am using 20 11 as my base template. I have created a child template, so please don’t freak out on me! My issue is that single post pages seem to use the class .hentry, so anything I want to apply to a single post page, is also applied to my home page.

.singular .hentry and .singular.page .hentry appear to be useless. So, how do I apply a style to a single post page without applying it to my home page (or vice versa)?? In this case, I have applied a bottom border to .hentry so as to viusally distinguish posts. Clearly, I do not need this border on my single post pages. Thank you in advance.