Flex Example
HTML
<div class="container">
<div>
<div class='h100'>Div 2</div>
<div class='h100'>Div 3</div>
</div>
<div>
<div class='h100percent'>
<div>Div 4</div>
</div>
</div>
CSS
.h100 {
height: 50px;
display: flex;
flex-direction: column;
flex-wrap: wrap-reverse;
justify-content: center;
align-items: stretch;
align-content: flex-start;
}
.h100percent {
height: 100%;
display: flex;
flex-direction: column;
flex-wrap: wrap-reverse;
justify-content: center;
align-items: stretch;
align-content: flex-start;
}
.container {
border: 1px solid black;
background: #ececec;
padding: 10px;
margin-left: 10px;
flex: 1;
height: 300px;
display: flex;
flex-direction: column;
flex-wrap: wrap-reverse;
justify-content: flex-start;
align-items: stretch;
align-content: flex-start;
}