<div></div>

html {
  display: table;
  height: 100%;
  width: 25px;
  margin: auto;
}

body {
  display: table-cell;
  vertical-align: middle;
}

div::before {
	line-height: 25px;
	font-size: 25px;
	content: "　　";
	background: white;
}
div {
	display: inline;
	outline: 25px ridge white;
	outline-offset: -40px;
	border: 25px dotted #ABABAB;
}