JSFiddle - React, Tailwind, and code Playground

HTML

<label id="label1">label без for <input id="inp" type="text"></label>
<br>
<br>
<br>
<label id="label2" for="inp">other label</label>

CSS

.outline_red {
  outline: dashed 2px red;
}

.outline_blue {
  outline: dashed 2px blue;
}

.border_green {
  border: solid 2px green;
}

JavaScript

label1.onmouseover = function() {
   this.control.classList.toggle('outline_red');
}

label2.onmouseover = function() {
   this.control.classList.toggle('border_green');
}

inp.onmouseover = function() {
   this.labels.forEach(label => label.classList.toggle('outline_blue'));
}