JSFiddle - React, Tailwind, and code Playground

HTML

<div class="parent">
    <div  class="child">a <br/> b</div>
    <div class="child">a</div>
</div>

CSS

.parent{
    width:100px;
    display:table;
    border:1px solid green;
}
.child{
    width:50px;
    background:blue;
    display:table-cell;
}
.child + .child{background:red;}