JSFiddle - React, Tailwind, and code Playground

HTML

<link rel="stylesheet" href="http://cdn.kendostatic.com/2013.1.514/styles/kendo.common.min.css">
<link rel="stylesheet" href="http://cdn.kendostatic.com/2013.1.514/styles/kendo.mobile.all.min.css">
<script src="http://code.jquery.com/jquery-1.9.1.min.js"></script>
<script src="http://cdn.kendostatic.com/2013.1.514/js/kendo.mobile.min.js"></script>
<div data-role="view" id="tabstrip-home" data-title="Flexbox test" data-stretch="true">
    <div class="mainmenu">
        <div class="header1">Header</div>
        <div class="button1">
            <a href="#page1" data-role="button">Button 1</a>
        </div>
        
        <div class="button2">
            <a href="#page1" data-role="button">Button 2</a>
        </div>
        <div class="button3">
            <a href="#page1" data-role="button">Button 3</a>
        </div>
        <div class="button4">
            <a href="#page1" data-role="button">Button 1</a>
        </div>
        <div class="footer1">Footer</div>
    </div>
</div>
<div data-role="view" id="page1" data-title="App">
    You just started the Kendo UI Mobile app!
</div>
<div data-role="layout" data-id="mobile-tabstrip">
    <header data-role="header">
        <div data-role="navbar">
            <span data-role="view-title"></span>
        </div>
    </header>
    
    <div data-role="footer">
        <div data-role="tabstrip">
            <a href="#tabstrip-home" data-icon="home">Home</a>
        </div>
    </div>
</div>
<div data-role="layout" data-id="blank"></div>
<script>
    var app = new kendo.mobile.Application(document.body, { transition: "slide", layout: "mobile-tabstrip" });
</script>

CSS

.mainmenu { 
  /* Old Syntax */
  display: -webkit-box;
  -webkit-box-orient: vertical;
  display: -moz-box;
  -moz-box-orient: vertical;
  /* New Syntax */
  display: -webkit-flexbox;
  -webkit-flex-direction: column;
  background-color: yellow; /* To see what area the container covers */
}

.header1 {
    background-color: gray;
  height: 20px;
}
.button1 {
    background-color: green;
      /* Old Syntax */
  -webkit-box-flex: 1;
  -moz-box-flex: 1;
  /* New Syntax */
  -webkit-flex: 1;
}
.button2 {
    background-color: yellow;
      /* Old Syntax */
  -webkit-box-flex: 1;
  -moz-box-flex: 1;
  /* New Syntax */
  -webkit-flex: 1;
}
.button3 {
    background-color: red;
      /* Old Syntax */
  -webkit-box-flex: 1;
  -moz-box-flex: 1;
  /* New Syntax */
  -webkit-flex: 1;
}
.button4 {
    background-color: silver;
      /* Old Syntax */
  -webkit-box-flex: 1;
  -moz-box-flex: 1;
  /* New Syntax */
  -webkit-flex: 1;
}
.footer1 {
    color: white;
    background-color: black;
    height: 20px;
}