JSFiddle - React, Tailwind, and code Playground

HTML

<div class="container">
<div class="inner inner1">

</div>
</div>

<div class="container">
<div class="inner inner2">

</div>
</div>

<div class="container">
<div class="inner inner3">

</div>
</div>

<div class="container">
<div class="inner inner4">

</div>
</div>

CSS

.container {
  position: relative;
  background: green;
  margin: 20px;
  height: 150px;
}

.inner {
  position: absolute;
  width: 20%;
  height: 20%;
  background: white;
}

.inner1 {
  left: 0;
  right: 0;
  margin: auto;
}

.inner2 {
  left: 0;
  right: 0;
  top: 0;
  bottom: 0;
  margin: auto;
}

.inner3 {
  left: 50%;
  transform: translateX(-50%);
  top: 0;
  
}

.inner4 {
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
  
}