.main
{
background-color:#669;
width:1200px;
margin-left:auto;
margin-right:auto;
height:1000px;
}
.content
{
background-color: #CCF;
width:100%;
height:1000px;
margin-top:5%;
position: absolute;
}
Despite setting the main class to a width of 1200px, all divs are not fitting within that limit.
The content class was given a 100% width, assuming it would be constrained by the main class which had a width of 1200px.
However, the content class is actually extending beyond the main class and occupying the entire page.