JSFiddle - React, Tailwind, and code Playground

HTML

<html>
  <head>
    <style>
      .container {
        width: 300px;
        height: 300px;
        background: gray;
        border: 2px solid black;
        display: flex;
      }
      .centerH {
        justify-content: center;
      }
      .centerV {
        align-items: center;
      }
      .left {
        justify-content: flex-start;
      }
      .right {
        justify-content: flex-end;
      }
      .top {
        align-items: flex-start;
      }
      .bottom {
        align-items: flex-end;
      }
      .box {
        width: 100px;
        height: 100px;
        background: blue;
      }
    </style>
  </head>
  <body>

    <div class="container centerH centerV">
      <div class="box"></div>
    </div>
    <div class="container left centerV">
      <div class="box"></div>
    </div>
    <div class="container right centerV">
      <div class="box"></div>
    </div>
    <div class="container centerH top">
      <div class="box"></div>
    </div>
    <div class="container centerH bottom">
      <div class="box"></div>
    </div>

  </body>
</html>