JSFiddle - React, Tailwind, and code Playground

JavaScript

var seed, nums, c;
    seed = [];
    nums = [];
    c = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXTZabcdefghiklmnopqrstuvwxyz!@#$%^&*()";

    window.addEventListener("mousemove", function (e) {
        if (nums.join('').indexOf(e.offsetX + e.offsetY) >= 0) {
            seed.push(parseInt(nums.join('')));
            nums = [];
            seed.length > 256 ? nums.splice(0, 1) : 1;
        }
        nums.push(e.offsetX);
        nums.push(e.offsetY);
    });

    var random = function (l, r) {
        r = r || '';
        if (l === 0) {
            return r;
        } else {
            return random(l - 1, r + c[seed[seed.length - l] % c.length]);
        }
    }

    window.addEventListener("click", function () {
        var pass = random(parseInt(window.prompt("How many characters should this password be?")));
        alert(pass);
    });