CSS values for DIV structure setup - html

Question

I need to setup the following DIV structure (See image below. It tells more than a 1000 words)
The structure consists of 2 colums. The main column (left) has a variable width and 100% height.
The right colums has a FIXED width of 380px and 100% height.
Then inside the right column I need 3 DIVS.
The top DIV has a fixed height of 200px and must be aligned to the top.
The bottom DIV has a fixed height of 150px and must be aligned to the bottom.
The middle DIV has a variable height and must fill up the space vertically.
This is the DIV setup And the CSS I have:
.main-content {
width: 100%;
padding: 0px;
}
.col-1 {
width: calc(100% - 380px);
min-height: calc(var(--vh, 1vh)*100);
background-color: #2693FF;
float: left;
}
.col-2 {
width: 380px;
min-height: calc(var(--vh, 1vh)*100);
float: right;
}
.col-2-top {
height: 200px;
background-color: #00B200;
}
.col-2-middle {
height: 100%;
background-color: #FF8000;
}
.col-2-bottom {
height: 100px;
background-color: #B25900;
}
<div class="main-content">
<div class="col-1"></div>
<div class="col-2">
<div class="col-2-top"></div>
<div class="col-2-middle"></div>
<div class="col-2-bottom"></div>
</div>
</div>
Then... Column 1 and 2 should stack when the viewport width becomes less than 768px.
Column 1 on top and Column 2 below it.
Like this:
I think I'm almost there, but I'm having problems with the height of the Main DIV and the heights and aligning of the DIV col-2 middle DIV. I also need a bit helpt to get these divs stack nicely above each each other.

Answer 1

I would suggest that you use grid layout instead of floating around your <div>s, grid layout allows you to structure your layout and separate them in columns and rows, and areas using grid-template-areas.
for max-width:748 just add media query, here is how it might be implemented:
body {
padding: 0;
margin: 0;
}
.main-content {
display: grid;
background-color: #2196F3;
grid-template-areas:
'main fixed-top'
'main variable-mid-area'
'main fixed-bottom';
background-color: #2196F3;
height: 100vh;
grid-template-columns: 1fr 380px;
grid-template-rows: 200px 1fr 150px;
}
.main-content > div {
color: #fff;
font-size: 30px;
vertical-align: middle;
display: flex;
justify-content: center;
align-items: center;
}
.main {
grid-area: main;
background-color: #2693FC;
}
.variable-mid-area {
grid-area: variable-mid-area;
background-color: #FF8015;
}
.fixed-top {
grid-area: fixed-top;
background-color:#00B21F;
}
.fixed-bottom {
grid-area: fixed-bottom;
background-color: #B2590B;
}
#media only screen and (max-width: 768px) {
.main-content {
grid-template-areas:
'main'
'fixed-top'
'variable-mid-area'
'fixed-bottom';
grid-template-rows: 300px 200px 1fr 150px;
grid-template-columns: 100%;
height: auto;
}
}
<div class="main-content">
<div class="main"> main </div>
<div class="fixed-top"> 200 </div>
<div class="variable-mid-area"> auto </div>
<div class="fixed-bottom"> 150 </div>
</div>

Answer 2

If you have any questions how the css works, feel free to ask them in the comments.
I know the background-colors are irrelevant but they help to visualize it.
.container {
min-width: 768px;
width: 100%;
display: grid;
grid-template-columns: calc(100% - 380px) 1fr;
min-height: 100vh;
}
.col1 {
background-color: dodgerblue;
}
.col2 {
display: flex;
flex-direction: column;
}
.col2-row1 {
height: 200px;
background-color: orange;
}
.col2-row2 {
background-color: forestgreen;
height: 100%;
}
.col2-row3 {
height: 150px;
background-color: red;
}
#media (max-width: 768px) {
.container {
grid-template-columns: 1fr;
}
}
<div class="container">
<div class="col1">1</div>
<div class="col2">
<div class="col2-row1">2</div>
<div class="col2-row2">3</div>
<div class="col2-row3">4</div>
</div>
</div>