JSFiddle - React, Tailwind, and code Playground

HTML

<div id="main_div">{main_div}
<!-- Content will come here -->
    <div id="inner_div">{inner_div}
    <!-- Social icons will come here and stays at bottom -->
    </div>
</div>
<div>
  Esto es otra cosa.
</div>

CSS

#main_div{
    position: relative;
    width: 400px;
    height: 400px;
    border: 2px solid #000000;
}
#inner_div{
    position: absolute;
    bottom: 0;
    left: 0;
    width: 400px;
    height: 50px;
    border: 2px solid #000000;
}