JSFiddle - React, Tailwind, and code Playground

HTML

<div class="incomplete-box">
Lorem ipsum dolor sit amet, consectetur adipisicing elit. Tempore in quae incidunt deleniti minima quibusdam, suscipit dignissimos cumque officia ullam.
</div>

CSS

body{
  background-color: gray;
}
.incomplete-box{
  border: solid 1px #fff;
  border-right: none;
  width: 100px;
  height: auto;
  position: relative;
}
.incomplete-box::after,
.incomplete-box::before{
  content: '';
  position: absolute;
  height: 30%;
  width: 1px;
  background-color: #fff;
  right: 0;
}
.incomplete-box::after{
  top: 0;
}
.incomplete-box::before{
  bottom: 0;
}