JSFiddle - React, Tailwind, and code Playground

HTML

<div class="content">
  Content
</div>
<div class="footer">
  Footer
</div>

CSS

body {
  margin: 0; /*Reset body margin*/
}

.content {
  min-height: calc(100vh - 10rem); /*10rem is the size of footer*/
}

.footer {
  height: 10rem;
  background-color: blue;
}