JSFiddle - React, Tailwind, and code Playground

HTML

<div class="pan row1"></div>
<div class="pan row2"></div>

CSS

div.pan {
       position: absolute;
       z-index: -1;
       left: 0;
       top: 0;

       height: 100px;  
       width: 100%;
       background: red;
    }

    div.row2 {
       top: 100px;
       background: blue;
    }