Change background for authenticated user I'm pleased with my body background for my site; it looks great when not logged in.  But when a user is logged in I need a different one.  I need to specify a slightly different background because of the fact that my Marinelli-based D7 site's custom body background (2 horizontal bands of green and black) stays in position but all content moves down almost 100px due to the administrative menu at the top.   

An authenticated user would not be able to see the navbar due to this color change  (green words on a now green background).  

Can I specify an alternate background for authenticated users vs. visitors?  Or perhaps better:  Is there a way to specify that the body background should move down when the user logs in and all the admin menus show up at the top?  

Here's my present CSS for body:

body.marinelli{
    background: #fff url(../img/backgrounds/body-background.jpg);
    background-repeat:repeat-x;
}
I think your solution would be the class "logged-in" and the CSS property "background-position" to move the background image down 100px for logged-in users:

body {
  background: #fff url(../img/backgrounds/body-background.jpg);
  background-repeat: repeat-x;
}

body.logged-in {
  background-position: 0 100px;
}