<button popovertarget="mypopover">Toggle the popover</button>
<div id="mypopover" popover=manual>Popover content <a href="#">link</a></div>

<button popovertarget="mypopover2">Toggle the second popover (red border)</button>
<div id="mypopover2" popover=manual>Popover content 2</div>

#mypopover {
  position: fixed;
  top: 100px;
  left: 0;
  margin: 0;
}
#mypopover2 {
  position: fixed;
  top: 130px;
  left: 0;
  margin: 0;
  border-color: red;
}