<!doctype html>
<style>
* { padding: 0; margin: 0; }
div { position: absolute;
top: 50px;
left: 50px;
width:1px;
height:1px;
background: rgba(0,0,255,0.5);
outline: 50px solid rgba(0,0,255,0.5); }
}
</style>
<div></div>