<!doctype html>
<style>
* { margin: 8; padding: 0; }
div {
position: absolute;
top: 50px;
left: 50px;
outline: 50px solid rgba(0,0,255,0.5);
background: rgba(0,0,255,0.5);
width: 1px;
height: 1px;
}
</style>
<div></div>