JSFiddle - React, Tailwind, and code Playground

CSS

html, body{height:100%}
#matrix{overflow:visible}

JavaScript

//(function () {
    // initialisation
    var Cols = 4,
    Cl = 20,
    Cs = 15,
    Ts = 14,
    Tc = '#008800',
    Tc1 = '#00ff00',
    MnS = 6,
    MxS = 6,
    I = Cs,
    A,
    Sp = new Array(),
    S = new Array(),
    Y = new Array(),
    C = new Array(),
    M = new Array(),
    B = new Array(),
    RC = new Array(),
    E = new Array(),
    Tcc = new Array(0, 0),
    Container = document.createElement("DIV");    
    Container.id='matrix';
    Container.style = 'position:absolute;top:0;right:-' + Cs + 'px';
    Container.innerHTML = "<div style='position:relative'>";
    for (i = 0; i < Cols; i++) {
        S[i] = I += Cs;
        Container.innerHTML += "<div class='A' style='position:absolute;top:0;font-family:comic sans ms;font-size:" + Ts + "px;right:" + S[i] + "px;width:" + Ts + "px;height:0px;color:" + Tc + ";visibility:hidden'></div>";
    }
    Container.innerHTML += "</div>";

    document.body.appendChild(Container);
    
    A = document.getElementsByClassName('A');
    for (j = 0; j < Cols; j++) {
        RC[j] = 1 + Math.round(Math.random() * Cl);
        Y[j] = 0;
        Sp[j] = Math.round(MnS + Math.random() * MxS);
        for (i = 0; i < RC[j]; i++) {
            B[i] = '';
            C[i] = Math.round(Math.random() * 1) + ' ';
            M[j] = B[0] += C[i];
        }
    };

    // boucle d'animation
    function Cycle() {
        Container.style.top = document.body.scrollTop;
        for (i = 0; i < Cols; i++) {
            var r = Math.floor(Math.random() * Tcc.length);
            E[i] = '<font color=' + Tc1 + '>' + Tcc[r] + '</font>';
            Y[i] += Sp[i];

            if (Y[i] > document.body.clientHeight) {
                for (i2 = 0; i2 < Cols; i2++) {
                    RC[i2] = 1 + Math.round(Math.random() * Cl);
                    for (i3 = 0; i3 < RC[i2]; i3++) {
                        B[i3] = '';
                        C[i3] = Math.round(Math.random() * 1) + ' ';
                       ...