JSFiddle - React, Tailwind, and code Playground

HTML

<div class="parent">
      <h1 class="child">Какой то текст</h1>
  </div>

CSS

body {
      height: 5000px;
      margin: 0;
      font-family: sans-serif;
    }
    .parent {
        position: fixed;
        top: 0;
        left: 0;
        width: 80%;
        padding: 30px;
        background-color: #03121b;
    }
    .child {
        font-size: 30px;
        color: red;
    }