/* Erst ma die Buttos aus dem Akkordion-Menue verbergen: */
      .accordion {
        display: none;
      }


      /* Style fuer das Menue */
      .tab {
        /*border: 1px solid #ccc; */
        height: 100%;
        width: 180px;
        position: fixed;
        z-index: 1;
        top: 0;
        left: 0;
        background-color: #111;
        /*background-color: #f1f1f1;*/
        overflow-x: hidden;
        padding-top: 16px;
      }


      /* Style fuer die Buttons in der Menueleiste */
      .tab button {
        padding: 6px 2px 6px 6px;
        width: 100%;
        text-decoration: none;
        font-size: 18px;
        display: block;
        cursor: pointer;
        text-align: left;
        color: rgb(150,150,150);
        background-color: inherit;
        border: none;
        color: #818181;
        float: left;
        outline: none;
        transition: 0.3s;
      }


      /* Change background color of buttons on hover */
      .tab button:hover {
        background-color: #ddd;
      }

      /* Create an active/current tablink class */
      .tab button.active {
        background-color: #ccc;
      }


      /* Style the tab content */
      .panel {
        margin-left: 180px;  /* Same as the width of the sidenav */
        display: none;
        padding: 6px 12px;
        border: none;
        /*background-color: #c1c;*/
      }



/*
lies:
https://www.w3schools.com/howto/howto_js_accordion.asp
https://www.w3schools.com/howto/howto_css_sidebar_icons.asp  (linker Tab, Nicht Lauffaehig)
https://www.w3schools.com/howto/howto_js_tabs.asp       (obere Tableiste. Lauffaehig)
https://wiki.selfhtml.org/wiki/HTML/Frames
https://www.mediaevent.de/xhtml/frameset.html
*/