.page {
    margin:0 auto;
    position:relative;
    width:90%;
    clear:both;
}
    .page .col1 {
        float:left;
    }
    .page .col2 {
        float:left;
    }
/* 
 * wrapper's class name is based on the left column's width
 * 
 * col60 – left column is ~60% wide
-------------------------------------*/
.col-left-60 .col1 {
    width:53%;
}
.col-left-60 .col2 {
    width:30%;float:left;margin-left:5%;
}
/* col70 – left column is ~70% wide
-------------------------------------*/
.col-left-70 .col1 {
    width:100%;
}
.col-left-70 .col2 {
    width:27%;
}
/* col25 – left column is ~25% wide
-------------------------------------*/
.col-left-25 .col1 {
    width:24%;
}
.col-left-25 .col2 {
    width:72%;
}
/* col50 – both columns are almost identical
-------------------------------------*/
.col-left-50 .col1,
.col-left-50 .col2 {
    width:48%;
}