JSFiddle - React, Tailwind, and code Playground

HTML

<div id="main-box">
      <div id="blue" class="box-test"></div>
      <div id="red" class="box-test"></div>
    </div>

CSS

.box-test {
  height: 200px;
  display: inline-block;
  width: 30%;
}

#blue {
  background-color: blue;
}

#red {
  background-color: red;
}

#main-box {
  text-align: center;
  border: 1px solid black;
  font-size:0;
}