body
{
    margin:0;
    background-color: seagreen;
} 

#container
{
    position:relative;
    height:100%;
    width:100%;
    min-width:400px;
} 


#content 
{
    position:absolute;
    top:50%;
    left:50%;
    transform:translate(-50%,-50%);
    outline:3px solid red;