How is a click outside of an element tracked?

Question

css

For example, there is a dropdown , which has a dropdown list when you click on it.
How to track a click outside of this element to close it?

Answer 1

Track the click on the document, and if event.target is not the desired element, then execute the closing code.
UPD: Example https://codepen.io/VladIT4/pen/vjNOKW