.pgn_mask{
position: relative;
overflow: hidden;
margin: 0px auto;
width: 100%;
background-color: #ffffff
}
.pgn_header{
float: left;
width: 100%;
background-color: #ffffff
}
.pgn_colleft{
position: relative;
width: 100%;
right: 50%;
background-color: #ffffff
}
.pgn_col1{
position: relative;
overflow: hidden;
float: left;
width: 48%;
left: 101%;
background-color: #ffffff
}
.pgn_col2{
position: relative;
overflow: hidden;
float: left;
width: 48%;
left: 3%;
background-color: #ffffff
}
.pgn_footer{
float: left;
width: 100%;
background-color: #ffffff
}
<div class="pgn_mask">
<div class="pgn_header">
header
</div>
<div class="pgn_colleft">
<div class="pgn_col1">
right
</div>
<div class="pgn_col2">
left
</div>
</div>
<div class="pgn_footer">
footer
</div>