JSFiddle - React, Tailwind, and code Playground

HTML

<div class="container">
    <div class="box">  </div>
</div>

CSS

.container{
    height: 60px;
    width: 80%;
    border: 2px solid #333;
    margin: 20px;
    overflow: hidden;
    position: relative;
    border-radius: 10px;
    -moz-border-radius: 10px;
    -webkit-border-radius: 10px;
}
.box{
    width: 50%;
    height: 96%;
    background: #fff;
    border-radius: 10px;
    -moz-border-radius: 10px;
    -webkit-border-radius: 10px;
    position: absolute;
    left: 200px;
    border: 1px solid red;
}