JSFiddle - React, Tailwind, and code Playground

HTML

<link rel="stylesheet" href="http://archive.dojotoolkit.org/nightly/dojotoolkit/dijit/themes/claro/claro.css">
<body class="claro">
    <div id="appContainer"></div> 
</body>

CSS

html, body {
    height: 100%;
    margin: 0;
    padding: 0;
    overflow: hidden;
}

JavaScript

require([
   "dojo/_base/declare",
    "dojo/on",
    
   "dijit/_WidgetBase",
   "dijit/_TemplatedMixin",
   "dijit/_WidgetsInTemplateMixin",

   "dijit/layout/BorderContainer",
   "dijit/layout/StackContainer",
   "dijit/layout/TabContainer",
   "dijit/layout/ContentPane"

   ], function(
     declare
     , on
     , _WidgetBase
     , _TemplatedMixin
     , _WidgetsInTemplateMixin

     , BorderContainer
     , StackContainer
     , TabContainer
     , ContentPane){

  declare('SubWidget', [ContentPane, _TemplatedMixin, _WidgetsInTemplateMixin], {
      
      templateString: '' +
      '  <div class="subWidget">' +
          
      '    <div style="height:100%" data-dojo-type="dijit.layout.TabContainer" data-dojo-props="tabPosition: \'left-h\'" data-dojo-attach-point="tabContainer" >' +

      '      <div data-dojo-type="dijit.layout.ContentPane" data-dojo-props="title: \'Second Widget one\'">Second Widget One</div>' +
      '      <div data-dojo-type="dijit.layout.ContentPane" data-dojo-props="title: \'Second Widget Two\'">Section Widget Two</div>' +

          '    </div>'+
        '    </div>',
      
   });                             
         
      var App = declare( [_WidgetBase, _TemplatedMixin, _WidgetsInTemplateMixin], {

      templateString: '' +
          '<div>' +
          '  <div class="bookingDojo" data-dojo-type="dijit.layout.BorderContainer" design: \'headline\'">' +
          
          '    <div data-dojo-type="dijit.layout.TabContainer" data-dojo-props="region: \'center\', tabPosition: \'left-h\'">' +

          
          '      <div data-dojo-type="dijit.layout.ContentPane" data-dojo-props="title: \'Main One\'">Main One</div>' +
          '      <div data-dojo-type="dijit.layout.ContentPane" data-dojo-props="title: \'Main Two\'">Main Two</div>' +

        '        <div data-dojo-type="dijit.layout.TabContainer" data-dojo-props="title: \'Complex\', tabPosition: \'top\'" >' +
        '          <div...