JSFiddle - React, Tailwind, and code Playground

HTML

<form action="" method="post">
    <h3>Formulario</h3>
    <input type="text" name="campo1" /><br />
    <button type="submit" name="enviar">Enviar</button>
</form>
<div id="loading">
    <img src="http://sierrafire.cr.usgs.gov/images/loading.gif" height="100" width="100" />
</div>

CSS

body{
    background-color:black;
    color:white;
}

JavaScript

$(document).ready(function(){
  $('#loading').hide();
  $('form').submit(function(){
    $('#loading').show();
  });
});