JSFiddle - React, Tailwind, and code Playground

HTML

<div class="right">
id 2</div>
<div class="left">
    <div class="top">id 1</div>
    <div class="content">id 3</div>
</div>

CSS

.right{
float:right;
width:25px;
height:25px;
background:#666;
}
.left{
margin-right:26px;
}
.top{
height:100px;
background:#eee;
border:1px solid #369;}
.content{
min-height:300px;
background:#999;
}