JSFiddle - React, Tailwind, and code Playground

HTML

<canvas></canvas>

CSS

body, html { padding: 0; margin: 0; width: 100vw; height: 100vh; }
* { box-sizing: border-box; }

JavaScript

let masterCanvas = document.querySelector('canvas');
let parent = masterCanvas.parentElement;
masterCanvas.width = document.body.offsetWidth;
masterCanvas.height = document.body.offsetHeight;