JSFiddle - React, Tailwind, and code Playground

JavaScript

var no = 10;
        var delai = 10;
        var dx = new Array(),
            xp = new Array(),
            yp = new Array();
        var am = new Array(),
            stx = new Array(),
            sty = new Array();
        var i;
        larg_fenetre = (document.body.offsetWidth < window.innerWidth) ? window.innerWidth : document.body.offsetWidth;
        haut_fenetre = (document.body.offsetHeight < window.innerHeight) ? window.innerHeight : document.body.offsetHeight;
        
        var iteration_max = 100;
        var iteration = 0;

        for (i = 0; i < no; i++) {
            dx[i] = 0;
            xp[i] = Math.random() * (larg_fenetre - 40);
            yp[i] = Math.random() * haut_fenetre;
            am[i] = Math.random() * 20;
            stx[i] = 0.02 + Math.random() / 10;
            sty[i] = 0.7 + Math.random();

            obj = document.getElementsByTagName('body')[0];
            para = document.createElement("img");
            para.setAttribute("src", "img/fall.png");
            para.setAttribute("id", "dot" + i);
            para.style.position = "absolute";
            para.style.zIndex = "2";
            obj.appendChild(para);
        }

        function neige() {
            for (i = 0; i < no; i++) {
                dx[i] += stx[i];
                yp[i] += sty[i];
                if (yp[i] > haut_fenetre - 50) {
                    xp[i] = Math.random() * (larg_fenetre - am[i] - 40);
                    yp[i] = 0;
                }
                document.getElementById("dot" + i).style.top = yp[i] + "px";
                document.getElementById("dot" + i).style.left = xp[i] + am[i] * Math.sin(dx[i]) + "px";
            }
            console.log(iteration);
            if (iteration < iteration_max) {
                setTimeout("neige()", delai);
                iteration++;
            }

        }

        neige();