JSFiddle - React, Tailwind, and code Playground

HTML

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

CSS

.box{
  width: 180px;
  height: 180px;
  border: 18px solid #f6d58c;
  background-color: #fff;
  display: flex;
  justify-content: flex-end;
  align-items: center;
}

.box:before{
  content: "";
  width: 18px;
  height:100px;
  float: left;
  background-color: blue;
  right: -18px;
  position: relative;
}