Resize the canvas for different window size

canvas.js

(function() {
    "use strict";

    function resizeCanvas() {
        var canvas = document.querySelector("#canvas");
        var context = canvas.getContext("2d");

        //Need to set the canvas size here, as it zoom with CSS
        canvas.width = window.innerWidth;
        canvas.height = window.innerHeight;
    }

    window.onload = function() {
       resizeCanvas();
    };

})();