With the best understanding of your question, I tried to give you an answer.
section {}
.main {
float: left;
position: absolute;
width: 400px;
height: 100%;
margin: auto 13%;
top: 0;
bottom: 0;
left: 0;
right: 0;
}
.section1 {
width: 40%;
}
.section2 {
width: 40%;
}
.section1,
.section2 {
margin: 0px;
padding: 0px;
padding: 0px 5px;
float: left;
position: relative;
height: 80%;
}
.section3 {
padding: 0px;
/*border: 1px solid #cccccc;*/
float: left;
position: relative;
width: 83%;
margin: 5px 5px;
height: 20%;
}
.section1 .inner-1 {
float: left;
width: 100%;
height: 100%;
border: 1px solid #000000;
}
.section2 .inner-1 {
float: left;
width: 100%;
min-height: 30%;
border: 1px solid #000000;
}
.section2 .inner-2 {
float: left;
width: 100%;
min-height: 30%;
border: 1px solid #000000;
margin: 10px 0px 0px 0px;
}
.section3 .inner-1 {
width: 100%;
float: left;
border: 1px solid #000000;
width: 100%;
height: 50%;
}
<section class="main">
<section class="section1">
<div class="inner-1">
</div>
</section>
<section class="section2">
<div class="inner-1"></div>
<div class="inner-2"></div>
</section>
<section class="section3">
<div class="inner-1"></div>
</section>
</section>
Hope it may helpful to you.
solved Acessing and positioning divs with css