Gap between posts

We meet again, I see.

You’ve got two choices. First, you could just style the lines you’ve already got, like so (using a hideous color so it will be obvious what’s going on):

hr{height:1em;border:none;background:#f00;}

Fiddle with the height to make it the size you want. And definitely change that hideous color I used.

SECOND, you could try something like this (again, with hideous colors):

.post{margin-bottom:3em;background:#00f;}
#content{background:#f00;}

With this option, you’d probably want to delete the <hr /> tags.

The #content background is what will show up between posts. The .post’s margin-bottom determines how much you’ll see.