JSFiddle - React, Tailwind, and code Playground

HTML

<div class="block1">бордер</div>
<div class="block2">тень</div>

CSS

div{
width:100px;
height:100px;
margin:0px 20px;   
border-radius:50px;
}

.block1{
border:1px solid #222;
box-sizing:border-box;    
}

.block2{
box-shadow:0px 0px 0px 1px #222;
}