JSFiddle - React, Tailwind, and code Playground

HTML

<div id="top_menu"><div id="overlay">
</div>
    <span>
        fasdfsfafasdfas
    </span>
</div>

CSS

#overlay{
    position: fixed;
  top: 0;
  right: 0;
  bottom: 0;
  left: 0;
  z-index: 1101;
  background-color: #000;
  opacity: 0.8;
}
#top_menu{
    position:fixed;
    top:0;
    left:0;
    right:0;
    height:200px;
    background-color:red;
    padding-top:40px;
    padding-left:40px;
  z-index: 1100;
}
#top_menu > span{
    font-weight:bold;
    color:white;
    font-size:30px;
    z-index:1102;
    position:relative;
}