JSFiddle - React, Tailwind, and code Playground

HTML

<input type='text' name='feld' class='inp' value='standard'/>
<label for='feld' class='help' data-helptext='Hilfe'></label>

CSS

.inp:hover + .help::after { 
  opacity: 1;
  transition: opacity 0.1s ease-in 0.4s;
}

.help::after {
  opacity: 0;
  content: attr(data-helptext);
  transition: opacity 0.1s ease-out;
}