JSFiddle - React, Tailwind, and code Playground

HTML

<div class="js-menu sliding-panel-content middle-content is-visible">
  <span class="closeBtn sliding-panel-close"></span>
  <div class="slide-content">


    <div class="super-image-thumb">
      <div id="product-gallery-super">
        <a href="#" class="product-gallery">
          <img src="http://placehold.it/61x79?text=1">
        </a>
        <a href="#" class="product-gallery">
          <img src="http://placehold.it/61x79?text=2">
        </a>
        <a href="#" class="product-gallery">
          <img src="http://placehold.it/61x79?text=3">
        </a>
        <a href="#" class="product-gallery">
          <img src="http://placehold.it/61x79?text=4">
        </a>        
        <a href="#" class="product-gallery">
          <img src="http://placehold.it/61x79?text=5">
        </a>
        <a href="#" class="product-gallery">
          <img src="http://placehold.it/61x79?text=6">
        </a>
      </div>
    </div>

    <div class="main-image-container">
      <img class="main-image" src="http://placehold.it/500x2045">

      <button name="prev" id="super-prev">Prev</button>
      <button name="next" id="super-next">Next</button>
    </div>


  </div>
</div>

CSS

.sliding-panel-content {
    z-index: 1204;
}
.middle-content {
    border-left: 1px solid #ddd;
    border-right: 1px solid #ddd;
}

.middle-content {
    position: fixed;
    left: 8%;
    top: auto;
    width: 85%;


 

}

.sliding-panel-content {
    overflow: auto;
    top: 0;
    bottom: 0;
    height: 100%;
    background-color: #fff;
    -webkit-overflow-scrolling: touch;
}

.sliding-panel-content.is-visible {
    -webkit-transform: translateX(0);
}

.slide-content {
    position:relative;
}
.super-image-thumb {
    position:fixed;
    background: #FFF;
    top:0;
    width:100%;
    z-index: 2;
}

.main-image-container {
    position:absolute;
    top:85px;
    z-index: 0;
}