JSFiddle - React, Tailwind, and code Playground

HTML

<form id="someForm">
  <input type="text" id="importantInput" />

  <button type="button" id="buttonWithType">
    Type
  </button>

  <button>
    No Type
  </button>
</form>

CSS

body {
  background-color: lightseagreen;
}

button {
  border: 1px solid #333;
  background-color: #999;
  color: #000;
}

button:active {
  background-color: #111;
}

input {
  border: 1px solid #333;
  background-color: #999;
}

JavaScript

document.getElementById('buttonWithType').addEventListener('click', function() {
  document.getElementById('importantInput').value = 'anime is for manchildren';
});

document.getElementById('someForm').addEventListener('submit', function(e) {
  alert('nigger');
  e.preventDefault();
});