<div class='parent'>
<div class='child'></div>
<div class='child2'></div>
</div>
.parent {
padding: 10px;
width: 150px;
display: flex;
justify-content: space-between;
background: red;
}
.child {
width: 2px;
height: 100%;
background: #fff;
}
.child2 {
width: 50px;
height: 200px;
background: black;
}