Q:

Unable to fix broken CSS which once worked

I am having a lot of trouble with this CSS in a large community wiki I run. It used to work just fine but has since stopped using the specified background image for the wiki and has broken the page formatting for the main page.
I was not the one to design the CSS, but was provided with it be a generous volunteer. The code is below, but I don't even know what is broken and what is not.
.body { 
background-image: url("http://i.imgur.com/Vb4KDsz.jpg");
background-position: top center;
margin:auto;
}

.WikiaPageContentWrapper {
background: #eadfbb;
border: 2px solid #0f1620;
}

.WikiaPageContentWrapper:before {
position: fixed;
left: 50%;
bottom: 35px;
padding-left: 115px;
content: url("http://i.imgur.com/Jg7GHkG.png");
}

#WikiaArticle:before {
position: absolute;
top: 120px;
left: -210px;
content: url("http://i.imgur.com/LVeNyOJ.png");
}
.WikiaPage { border: 0 }

To actually address the problem, it would be easier to link the wiki and you can see for yourself that the CSS only actually inserts the final part of code. Here is the link 
For example, the main page is very oddly formatted depending on your screen resolution, and the background image specified in the CSS has been replaced by a grey background, along with the second image in the above code.

For some reason, after fiddling with the first answer, it caused something to change and the background to be restored. While the background itself is fixed, the page is far too wide, which is the formatting problem I addressed earlier. The new/old code is:
.i18ndoc {
background-color: #FFF77D;
border-bottom: 1px solid lightgrey;
font-family: monospace;
font-size: 8pt;
height: 140px;
overflow: auto;
padding: 3px;
}

body.mediawiki{
background:url("http://i.imgur.com/W23xCc6.jpg") repeat-x fixed center top #0f1620;
}
.WikiaPageContentWrapper {
background: #eadfbb;
border: 2px solid #0f1620;
margin-top: 10px;
}

.WikiaPageContentWrapper:before {
position: fixed;
left: 50%;
bottom: 50px;
padding-left: 170px;
content: url("http://i.imgur.com/Jg7GHkG.png");
}
#WikiHeader:before {
position: absolute;
top: 270px;
left: -200px;
content: url("http://i.imgur.com/LVeNyOJ.png");
}
.WikiaPage {
border: 0 !important;
}
footer {
position: relative;
z-index: 1;
}

.infobox tr {
line-height: 1em;
}
.infobox tr img {
margin-bottom: 10px;
}

With that fixed (thanks for the help) how do I reduce the width of the screen? If you go to the homepage of link you can see the issue. Any help will be appreciated.

A:

That is happening because Wikia recently renamed a few of their classes with the recent Fluid Layout features they implemented a few weeks ago.
All you need to do is change .body to body.background-dynamic.skin-oasis and your background will show up again.
That being said, you will probably have other issues related to the Fluid Layout changes that have completely fubar'd something or another. If you notice anything else please contact me on my MessageWall
at Community Central. I'll be more than happy to assist you with anything you need.

