styling a horizontal line between posts

Hi,

I have used this to add a line between blog posts:

/*add horizontal line between posts*/
.hentry {
    border-bottom:4px solid #ccc;
}

Is it possible to specify a width to the line so it doesn’t go across the whole page?

Also the line is below the title of my posts and i would like it to be above.

http://kiraaskaroff.com/BB_Test2/?cat=7

Thanks a lot.