JSFiddle - React, Tailwind, and code Playground

HTML

<div class="box1"></div>
<div class="box2"></div>
<div class="box3"></div>

CSS

.box1, .box2, .box3 {
  box-sizing: border-box;
}

.box1, .box2, .box3 {
  width: 150px;
  height: 250px;
  border: 1px solid red;
}

.box1 {
  border: 1px solid green;
  float: left;
}

.box2 {
  border: 1px solid green;
  float: left;
}
.box3 {
  border: 1px solid blue;
  float: right;
}