JSFiddle - React, Tailwind, and code Playground

HTML

<div class="wrap">
    <div class="left">
    <div class="left-main">
        Left
    </div>
</div>
<div class="right right-main">
    Right
    <div class="bottom-right">
        Bottom Right
    </div>
</div>
</div>

CSS

.wrap {
    display: block;
    position: relative; }
.left {
    display: inline-block;
}
.right {
    float: right;
}
.left-main {
    width:200px;
    height: 500px;
    background-color: red;
}
.right-main {
    position: absolute;
    bottom: 0;
    right: 0;
    width: 100px;
    height: 30px;
    background-color: green;
}
.bottom-right {
    background-color: blue;
}