Flexbox column layout: 1 to left and two stacked on right - html

Question

I'm trying to achieve the following responsive grid-layout using flexbox, but i can't manage to get the "desktop"-version right without a fixed height. I want #1 to be on its own to the left and #2 and #3 stacked on each other to the right (#1 does not have to have the same height as the right col)
HTML (simplified)
<div class="wrapper">
<div class="inner">
<div class="col1"></div>
<div class="col2"></div>
<div class="col3"></div>
</div>
</div>
CSS (simplified)
.wrapper {
max-width: 600px;
margin: 0 auto;
border: 1px solid #c4c4c4
}
.col1, .col2, .col3 {
background: #fe4c4c;
position: relative;
margin: 10px;
padding: 5px;
color: #FFF;
font-weight: bold;
font-size: 40px;
font-family: sans-serif;
min-height: 100px;
&:after {
position: absolute;
top: 50%;
left: 50%;
transform: translate(-50%, -50%);
}
}
.col1 {
&:after {
content: '1';
}
width: 100px;
}
.col2 {
&:after {
content: '2';
}
width: calc(100% - (100px + 60px))
}
.col3 {
&:after {
content: '3';
}
width: calc(100% - 30px);
}
.inner {
width: 100%;
display: flex;
flex-wrap: wrap;
}
#media only screen and (min-width: 768px) {
.inner {
flex-direction: column;
}
.col1 {
width: 300px;
}
.col2 {
width: auto;
}
.col3 {
width: auto;
}
}
jsFiddle
https://jsfiddle.net/pcwudrmc/28053/
I've search around for similar problems but can't find an answer without fixed height.
Thanks in advance!

Answer 1

Solution using CSS grid:
https://codepen.io/seanstopnik/pen/bd511c728bb79d02d11ae04edbfe9a33
* {
box-sizing: border-box;
}
.wrapper {
max-width: 600px;
margin: 0 auto;
border: 1px solid #c4c4c4;
padding: 10px;
}
.col1,
.col2,
.col3 {
background: #fe4c4c;
position: relative;
color: #fff;
font: {
family: sans-serif;
size: 40px;
weight: 700;
}
min-height: 100px;
&:after {
position: absolute;
top: 50%;
left: 50%;
transform: translate(-50%, -50%);
}
}
.col1:after {
content: '1';
}
.col2:after {
content: '2';
}
.col3:after {
content: '3';
}
// Inner
.inner {
display: grid;
grid: {
template-columns: 100px auto;
template-rows: 100px;
gap: 10px 10px;
}
#media (min-width: 768px) {
grid-template-columns: 300px auto;
}
}
.col1 {
#media (min-width: 768px) {
grid: {
column: 1 / span 1;
row: 1 / span 2;
}
}
}
.col3 {
grid: {
column: 1 / span 2;
row: 2 / span 2;
}
#media (min-width: 768px) {
grid: {
column: auto;
row: auto;
}
}
}

Answer 2

It can be done with Flexbox.
Based on the answer of Nenad Vracar to this question Flexbox/Float - 2 1 2 Layout I did this:
body,
html,
ul {
margin: 0;
padding: 0;
}
* {
box-sizing: border-box;
}
ul {
display: flex;
height: 100vh;
list-style-type: none;
flex-direction: column;
flex-wrap: wrap;
}
li {
flex: 0 0 50%;
border: 1px solid black;
display: flex;
align-items: center;
justify-content: center;
font-size: 50px;
}
li:nth-child(1) {
flex: 0 0 100%;
}
<ul>
<li>1</li>
<li>2</li>
<li>3</li>
</ul>
It gives you one item to the left with 100% height and two stacked one over the other on the right with 50% height each. This is the result: