JSFiddle - React, Tailwind, and code Playground

HTML

<input type="text" value="ostemad">
 <input type="text" value="banan">
 <input type="text" value="leverhørmer">
 <input type="text" value="abemad">
 <input type="text" value="hotdog">

CSS

input[type="text"] { color: #aaa; }
 input.selected { color: #000; }

JavaScript

$("input[type=text]").each(
     function(i,elm) {
         var $this = $(this),
             val = $this.val();
 
         $this
             .focus(function(e) {
                 $this
                     .val('')
                     .addClass("selected");
             })
             .blur(function(e) {
                 if($this.val() == "") {
                     $this
                         .val(val)
                         .removeClass("selected");
                 }
             });
     }
 )