JSFiddle - React, Tailwind, and code Playground

by Oleg Khobotov

HTML

<div class="first">
    500px без паддинга; 
<div class="second">
    50%;
</div>
</div>

CSS

.first{
width: 500px;
background-color: red;
padding-right: 300px; 
box-sizing: border-box;     
}

.second{
width: 50%;
background-color: yellow;    
}