JSFiddle - React, Tailwind, and code Playground

HTML

<div class="container">
      <div class="left">
        small left
      </div>
      <div class="left">
          left content<br />left content<br />left content
      </div>
      <div class="right">
        top right
      </div>
      <div class="right last">
        bottom right
      </div>
    </div>

CSS

.container{
    background:#ddd;
    width:400px;
    overflow:auto;
}
.container>div{
    box-sizing:border-box;
    padding:10px;
    width:50%;
}
.left{
    float:left; clear:left;
}
.leftno{
    float:left; clear:left;
}
.right{
    float:right; clear:right;
    background:#eee;
}
.right.last{
    background:#ccc;
}