JSFiddle - React, Tailwind, and code Playground

HTML

<div>
  <button>Кнопка</button>
</div>

CSS

div {
  height: 2000px;
  background: linear-gradient(#e66465, #9198e5);
}

button {
  top: 30px;
  left: 30px;
  position: fixed;
}