JSFiddle - React, Tailwind, and code Playground

HTML

<div class="flex">
        <span class="my-btn btn-back">back</span>

        <span class="my-btn btn-download">download</span>

        <span class="my-btn btn-next">next</span>
    </div>

CSS

.flex {
  display: -webkit-box;
  display: -moz-box;
  display: -ms-flexbox;
  display: -webkit-flex;
  display: flex;
  justify-content: space-between;
}

.my-btn {
  width: 150px;
  height: 50px;
  background-color: #3f729b;
  line-height: 50px;
  text-align: center;
  color: #FFFFFF;
  cursor: pointer;
  display: inline-block;
}

.btn-next {
  margin-left: auto;
}

.btn-back {
  margin-right: auto;
}

.btn-download, .btn-back {
  display: none;      
}