JSFiddle - React, Tailwind, and code Playground

HTML

<div id="border1"></div>

CSS

#border1 {
height:300px;
width:300px;
background:transparent;
border-top-style:solid;
border-top-width:1px;
border-top-color:black;
border-top-left-radius:0px;
border-top-right-radius:0px;
border-bottom-style:solid;
border-bottom-width:1px;
border-bottom-color:black;
border-bottom-left-radius:0px;
border-bottom-right-radius:0px;
border-left-style:solid;
border-left-width:1px;
border-left-color:black;
border-right-style:solid;
border-right-width:1px;
border-right-color:black;
}