JSFiddle - React, Tailwind, and code Playground

HTML

<div class="overlay"></div>
<div class="rect rect-1"></div>
<div class="rect rect-2"></div>
<div class="rect rect-3"></div>

CSS

body {
  height: 100%;
  margin: 0;
  padding: 0;
  background: yellow;
}

.overlay {
  position: absolute;
  width: 100%;
  height: 100%;
  background: rgba(0,0,0,0.5);
  z-index: 1;
}

.rect {
  position: absolute;
  border: 1px solid white;
  z-index: 2;
}

.rect-1 {
  left: 50px;
  top: 50px;
  width: 50px;
  height: 50px;
}

.rect-2 {
  left: 150px;
  top: 150px;
  width: 100px;
  height: 25px;
}

.rect-3 {
  left: 400px;
  top: 80px;
  width: 70px;
  height: 45px;
}