JSFiddle - React, Tailwind, and code Playground

HTML

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html>
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=no">
  <title>Meine nächste HTML/CSS Seite</title>
 
 
  <link rel="stylesheet" href="css/Seite02css.css">
 
 
  <!--Bootstrap auf entferntem Server -->
   <link rel="stylesheet" href="//cdnjs.cloudflare.com/ajax/libs/bootstrap-table/1.12.1/bootstrap-table.min.css">
   <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/css/bootstrap.min.css">
   <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
   <script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.12.9/umd/popper.min.js"></script>
   <script src="https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/3.3.6/js/bootstrap.min.js"></script>
   <script src="//cdnjs.cloudflare.com/ajax/libs/bootstrap-table/1.12.1/bootstrap-table.min.js"></script>
 
 
</head>
 
   <script src="js/Seite02js.js"></script>
 
<body onload="ausblenden()">
 
<img id="titel" src="bilder/anmeldung.png">
<img id="molekuele" src="bilder/molekuele.png">
<p> Klicken Sie bitte auf Ihr<br> Gebäude</p>
<ul class="bottom-nav nav nav-pills  d-flex justify-content-end fixed-bottom">
      <li><a id="einblenden" onClick="einblenden()" class="btn btn-outline-warning btn-space" role="button">Beenden</a></li>
      <li><a href="Nobi_Seite01.htm" class="btn btn-outline-warning btn-space" role="button">Zurück</a></li>
</ul>
 
 
 
<div class="container">
<div class="container">
  <div class="row">
    <div class="col-md-4">
        <table class="table table-hover"
             id="table"
             data-height="400"
             data-sortable = "true"
        <colgroup>
        <col class="col-md-3">
        </colgroup>
 
        <thead>
            <tr class="bg-primary">
               <th data-field="Bezeichnung">Geb&aumlude/Arbeitsplatz</th>
            </tr>
        </thead>
     ...

JavaScript

function ausblenden() {
     document.getElementById("hinweis").style.display='none';
}
function einblenden() {
     document.getElementById("hinweis").style.display='block';
}