我添加了一些javascript，它使用event.preventDefault（）方法来确保在单击图标时输入不会被聚焦。

const infoIcon = document.querySelector('.info-icon');
const popup = document.querySelector('#popup');

infoIcon.addEventListener('click', function(event) {
  event.preventDefault(); // prevent default behavior of focusing on the input
  
//toggles the popup on click/touch of the icon
popup.style.display = popup.style.display === 'none' ? 'block' : 'none' 
});

span {
  border: 1px solid red;
}

#popup {
   position:absolute;
   display:none;
   width:50px;
   height:50px;
   border-style:solid;
   background-color:yellow;
}

.info-icon:hover + #popup { /*uses the '+' adjacent child selector to display popup on hover*/
  display: block;
}

<label for="myInput">
  I am a label! <span class="info-icon">icon</span>
  <div id='popup'>POP UP</div>
</label>
<input id="myInput"/>