<body>
  <main>
    <h1>L'interMEDIAire</h1>
    <h2>Avant - Après</h2>
    <div id="beer-slider" class="beer-slider" data-beer-label="" data-beer-start="50">
      <img src="https://picsum.photos/id/102/600/400
" alt="Original - Man holding beer">
      <div class="beer-reveal" data-beer-label="">
        <img src="https://picsum.photos/id/102/600/400?blur=6">
      </div>
    </div>
  </main>
</body>
/*COULEURS*/
$noir:        rgba(0,0,0,1);
$noirfonce:   rgba(29,31,32,1);
$noiropaque:  rgba(29,31,32,.9);
$rose:        rgba(152,38,114,1);
$bleu:        rgba(128,155,189,1);
$blanc:       rgba(255,255,255,1);
$gris:        rgba(55,55,55,1);
$gris2:       rgba(255,255,255,.8);
$gris3:       rgba(204,204,204,1);
$padding:     20px 10px;

/*TOUS LES ELEMENTS*/
*,*:after,*:before {
  box-sizing: border-box;
  -moz-box-sizing: border-box;
  -webkit-box-sizing: border-box;
}

body {
  margin: 0px auto;
  width: 640px;
  background: $noir;
  color: $blanc;
  font-size: 1em;
  padding: $padding;
}

main {
  padding: $padding;
  background: $noirfonce;
}

a {
  color: $bleu;
  text-decoration: none;
  transition: all .3s ease-in-out;
}

a:hover,a:active {
  color: $blanc
}

h1 {
  margin: 0;
  padding: 0;
  font-size: 1.4em;
  color: $bleu;
}

h2 {
  margin-top: 15px;
  width: 100%;
  color: $rose;
}

h3 {
  display: inline-block;
  margin: 10px 0px;
  color: $gris2;
  text-transform: uppercase;
}

h1,h2,h3 {
  font-family: 'Inconsolata', monospace;
}

hr {
  margin-top: 20px;
  border: 0px solid $bleu;
  border-bottom-width: 1px;
}

p {
  opacity: .85;
  color: $gris2;
  line-height: 1.6em;
}

ul {
  margin: 0;
  padding: 0;
  color: $gris3;
  list-style: none;
}

img {
  margin-top: 20px;
  width: 100%;
  height: auto;
  -webkit-filter: grayscale(100%); /* Safari 6.0 - 9.0 */
  filter: grayscale(100%);
}

/*www.lintermediaire.be*/
View Compiled
  $.fn.BeerSlider = function ( options ) {
    options = options || {};
    return this.each(function() {
      new BeerSlider(this, options);
    });
  };
  $('.beer-slider').BeerSlider({start: 50});

External CSS

  1. https://unpkg.com/beerslider/dist/BeerSlider.css

External JavaScript

  1. https://unpkg.com/beerslider/dist/BeerSlider.js
  2. https://cdnjs.cloudflare.com/ajax/libs/jquery/3.5.1/jquery.min.js