I don't know if someone changed default themes, if so, it wasn't me :)
This is my a part of my CSS style (from http://squark.pl), bold fragments are important:
{{
#container {
margin: 0 auto; // make the page centered
width: 1000px; // fixed width 1000px
padding: 0;
}
#content-wrap{ // one big div where is all page (except background of course)
padding:0; margin:0;
border-bottom: 10px solid white;
border-right: 10px solid white; // +10px border
border-left: 10px solid white; // +10px border
background-color: #222222;
}
#side-bar{ // side bar (nav:side))
background-color: #3D3D3D;
border-left: 2px solid black; // +2px border
float: right;
width: 300px; // +300px width of the sidebar
padding-top: 0px;
padding-bottom: 0px;
padding-left: 10px; // paddings
padding-right: 10px; // paddings
margin: 0 0 0 0; // 0 margins
clear: both;
}
#main-content{
margin-top: 85px;
margin-left: 0; // no margins
margin-right: 0; // no margins
padding-left: 20px; // +20px padding
padding-right: 20px; // +20px padding
padding-top: 10px;
padding-bottom: 10px;
width: 610px; // width of the page content 610px
background-color: #222222;
}
}}
When you'll add everything: 10+10+2+300+10+10+20+20+610 = 992, it couldn't be more than 1000px from #container, even better if it's a little bit less than.
