The div below (containing the label and iframe but not the buttons) has event handlers for mousedown, mouseup, and
mouseleave, each of which logs to the console.
The iframe starts with pointer-events: none, which gets removed by the div's mousedown handler and replaced by the
div's mouseup and mouseleave handlers.
Usually, the div will receive the mouse events for the iframe when pointer-events: none is present, but the iframe will
receive the mouse events when it is not. Thus, the div typically receives the mousedown but not the mouseup when the
user clicks on the iframe.